Rapid-recall takeaways distilled from the MRCS Part A question bank, grouped by specialty. One pearl per high-frequency concept. Use it for last-pass revision alongside questions, not as a replacement for them.
603 pearls · 8 specialties · Generated 6 November 2026
Applied Surgical Anatomy
80 high-yield facts
Hartmann procedure creates an end colostomy and closed rectal stump - it is the standard emergency procedure for perforated diverticulitis with faecal peritonitis (Hinchey III/IV).
Tracheostomy traverses skin, platysma, investing fascia, strap muscles, pretracheal fascia, thyroid isthmus, and trachea - the brachiocephalic artery anterior to the trachea is at risk of fatal haemorrhage from erosion.
Allen's test assesses ulnar collateral circulation before radial artery cannulation - the dual blood supply via the palmar arches usually protects the hand, but an abnormal Allen's test mandates using an alternative site.
The inferior parathyroid glands migrate with the thymus (third pharyngeal pouch) - ectopic inferior glands are most commonly found in the thyrothymic ligament or thymus in the anterior mediastinum.
The ACL runs from the anterior tibia to the lateral femoral condyle - on sagittal MRI it appears as a low-signal band, and disruption with high signal confirms the tear.
The uterus lies posterior to the bladder on pelvic ultrasound - the Pouch of Douglas is the most dependent peritoneal space posteriorly and is assessed for free fluid in acute presentations.
The hypoglossal nerve crosses the ICA and ECA above the bifurcation - injury causes tongue deviation towards the affected side, and the vagus nerve in the carotid sheath is at risk of causing vocal cord palsy.
The caecum is the widest part of the large bowel in the right iliac fossa - an apple-core lesion on barium enema represents an annular carcinoma, most commonly in the sigmoid colon.
The main portal vein is the key ultrasound landmark for the gallbladder - it lies anterior to the portal vein at the junction of right and left liver lobes.
The ampulla of Vater lies on the posteromedial wall of D2 - ERCP involves cannulation of this papilla, and pancreatitis is the most common complication at 3-5% incidence.
Applied Surgical Physiology
80 high-yield facts
CPP = MAP - ICP, target 60-70mmHg - ICP >22mmHg requires treatment, and a single episode of systolic BP <90mmHg doubles TBI mortality.
TT = fibrinogen to fibrin - prolonged by low/dysfunctional fibrinogen, heparin, DIC.
BMR = lean body mass (dominant) + age + sex + thyroid status - estimate with Harris-Benedict or Mifflin-St Jeor; hypothyroidism, ageing, and starvation lower BMR, while pyrexia, sepsis, and hyperthyroidism raise it.
surgical smoke contains carcinogens, viable cells, and viral DNA - use dedicated smoke evacuation within 2cm of the source and high-filtration masks. Standard surgical masks do NOT adequately filter surgical smoke particles.
Crystalloids distribute in the ECF (25% intravascular), colloids initially remain intravascular - balanced crystalloids (Hartmann's) are preferred over 0.9% NaCl to avoid hyperchloraemic acidosis, and HES is contraindicated in critically ill patients.
eye protection specific to the laser wavelength is the most critical safety measure - eye injury is the most common serious laser complication. Use laser-safe ETT for airway surgery and keep FiO2 <0.4 to reduce fire risk.
Somatostatin is a universal GI inhibitor - octreotide is used for variceal bleeding, high-output fistulae, and NETs, and somatostatinomas present with diabetes, gallstones, and steatorrhoea.
Post-thyroidectomy hypocalcaemia = parathyroid injury or devascularisation - presents 24-72h; treat with calcium, calcitriol; check magnesium.
prehabilitation = exercise + nutrition + psychology + smoking/alcohol cessation before surgery. CPET with AT <11mL/kg/min predicts high risk. 'Better in, better out' - 3-6 weeks of structured exercise improves outcomes.
Common Surgical Conditions
80 high-yield facts
Murphy's sign = inspiratory arrest during RUQ palpation; diagnose with Tokyo Guidelines (local signs + systemic inflammation + ultrasound findings); USS is first-line imaging; 5 Fs describe the classic patient profile.
Classic appendicitis = periumbilical pain migrating to RIF + anorexia + low-grade fever + raised WCC/CRP; Alvarado ≥7 is highly suggestive; CT is the gold standard imaging modality.
Type II endoleak = branch vessels; often observe; intervene if sac growth; Type I/III need repair.
Penetrating chest trauma + Beck's triad → FAST scan, pericardiocentesis to temporise, emergency thoracotomy for definitive cardiac repair (ATLS 10th edition, NICE NG39); never rely on a chest drain alone.
AUR = urgent catheterisation; record residual; alpha-blocker before TWOC at 2-3 days; identify precipitants; TURP if TWOC fails; monitor for post-obstructive diuresis in high residuals.
Nissen fundoplication (360° wrap) for PPI-refractory GORD with normal motility; requires endoscopy + manometry + pH study pre-operatively; partial wrap for impaired motility; 85-90% long-term success; main complications are dysphagia and gas-bloat.
NICE NG12 - urgent 2-week wait referral for rectal bleeding + change in bowel habit, or iron deficiency anaemia; colonoscopy is the gold standard; FIT for lower-risk symptomatic patients; right-sided = anaemia, left-sided = change in bowel habit; CEA is for surveillance not diagnosis.
Femoral hernia = below and lateral to pubic tubercle; rigid boundaries cause 22-45% strangulation rate; ALL femoral hernias need urgent repair; McEvedy approach preferred for strangulated cases; beware corona mortis (aberrant obturator artery) when dividing the lacunar ligament.
ESWL for renal stones <20 mm, radio-opaque, unobstructed; stop anticoagulants; contraindicated in pregnancy; PCNL for stones >20 mm; steinstrasse is a recognised complication.
POVL from ischaemic optic neuropathy is the most feared prone position complication - risk factors include prolonged surgery, blood loss, hypotension; protect eyes from direct pressure; allow abdomen to hang free to prevent venous congestion.
POI management: reduce opioids, mobilise, chewing gum, correct electrolytes, NG drainage if needed - ERAS reduces POI through laparoscopic surgery and opioid-sparing analgesia; investigate if ileus persists beyond 5-7 days (CT to exclude mechanical cause or leak).
New neurological deficit after CEA = CT head to exclude haemorrhage then urgent re-exploration. The cause is usually carotid thrombosis or embolism at the surgical site. Time-critical surgical emergency. The correct answer is C.
New postoperative AF: rate control (beta-blocker/amiodarone), correct precipitants (sepsis, K⁺, Mg²⁺, hypoxia) - most cases revert within 48 hours; anticoagulate if AF persists >48 hours based on CHA₂DS₂-VASc; DC cardioversion only if haemodynamically unstable.
Achieve euthyroid state with antithyroid drugs and beta-blockers before thyroidectomy - Lugol's iodine for 10-14 days preoperatively reduces vascularity; operating on uncontrolled hyperthyroidism risks life-threatening thyroid storm.
Non-pharmacological multicomponent interventions are first-line for delirium - orientation, sleep hygiene, mobilisation, pain control, remove unnecessary lines, sensory aids; 4AT screens for delirium; haloperidol only for severe agitation; benzodiazepines worsen delirium (except alcohol withdrawal).
Morbid obesity reduces FRC and oxygen reserve causing rapid desaturation - ramped positioning, pre-oxygenation, apnoeic oxygenation, and careful drug dosing on appropriate weight metrics (lean vs total) are essential.
Chronic respiratory acidosis = renal compensation (elevated bicarbonate); acute-on-chronic = low pH with high PaCO2 and bicarbonate.
The lethal triad = Hypothermia + Acidosis + Coagulopathy. DCS phases: (1) abbreviated surgery, (2) ICU resuscitation, (3) definitive repair. Physiology drives the decision, not anatomy.
Applied Surgical Pathology
80 high-yield facts
PSP = apical bleb rupture in tall, thin, young males. SSP = underlying lung disease (COPD most common). Tension pneumothorax = clinical diagnosis, decompress immediately. BTS: PSP >2 cm → aspirate first. 30% recurrence rate.
Postoperative platelet drop >50% on days 5-14 of heparin = think HIT immediately - stop ALL heparin, calculate 4T score, send HIT antibodies, and switch to an alternative anticoagulant.
Tendinopathy = degenerative (angiofibroblastic), NOT inflammatory. No inflammatory cells on histology. Disorganised collagen + neovascularisation + mucoid change. Eccentric exercises are first-line treatment. Corticosteroid injections give short-term relief but may worsen long-term outcomes.
Rh HDFN = maternal IgG anti-D crossing the placenta → fetal extravascular haemolysis - prevention with routine anti-D prophylaxis is essential; IgM does NOT cross the placenta, only IgG does.
Ganglion = mucoid degeneration (NOT synovial herniation). Dorsal wrist most common site. Viscous jelly-like fluid. Transillumination positive. Aspiration: 50% recurrence. Surgical excision: 5-10% recurrence. Many resolve spontaneously. Most common soft tissue swelling of the hand/wrist.
The two cardinal features of irreversible injury are membrane disruption and severe mitochondrial dysfunction with flocculent densities. Nuclear changes (pyknosis, karyorrhexis, karyolysis) confirm the diagnosis histologically.
FMF = autoinflammatory (innate immunity, not autoimmune). MEFV gene → pyrin dysfunction → uncontrolled IL-1β → neutrophilic serositis. Colchicine is first-line treatment and prevents AA amyloidosis. Common cause of unnecessary laparotomy.
Pyogenic granuloma = misnomer - it's a lobular capillary haemangioma. Not infective, not granulomatous. Rapid growth, pedunculated, bleeds easily. Always send for histology to exclude amelanotic melanoma. Pregnancy epulis = gingival pyogenic granuloma. Excision + cauterisation is treatment.
Trauma Assessment and Management
80 high-yield facts
SI >0.7 = abnormal, >0.9 = significant shock, >1.0 = severe shock, >1.5 = life-threatening. Higher SI values correlate with increased mortality, transfusion requirements, and need for emergency surgery. It is a simple, rapid, bedside assessment tool.
Operate for open fractures, failed closed reduction, unacceptable alignment, or floating elbow. Consider fixation for older children (>10 years) with less remodelling potential. Monitor for compartment syndrome.
Individualise based on injury pattern. Major trauma, pelvic fracture, spinal cord injury increase risk. Consider extended prophylaxis after discharge in high-risk patients. Inferior vena cava filter in selected cases when anticoagulation contraindicated.
The 'white-eyed blowout fracture' in children is an emergency - minimal bruising but severe entrapment with bradycardia (oculocardiac reflex). This requires urgent surgery within 24-48 hours.
'Chest, pelvis, lateral C-spine' is the ATLS teaching. In modern trauma practice, CT has superseded plain films in stable patients, but portable chest and pelvis X-rays remain essential for unstable patients.
MAP ≥85 mmHg for 5-7 days. Methylprednisolone is NOT recommended (outdated NASCIS protocols). Early surgery for incomplete injuries (<24 hours). Multidisciplinary rehabilitation from day one. Autonomic dysreflexia prevention in injuries above T6.
Open tibia = debridement + antibiotics + stabilisation. IM nail or ex-fix. Soft tissue determines approach. Early antibiotics.
Maintain immobilisation until clinical and/or radiological clearance. Consider CT for high-risk mechanisms; MRI for neurological deficit or persistent pain with normal X-ray. Age-appropriate collars are essential.
Gartland classification guides management. Type II-III often need closed reduction and K-wire fixation. Urgent reduction relieves vascular compromise. Volkmann ischaemic contracture is a devastating late complication of missed compartment syndrome.
Surgical Pharmacology and Investigations
65 high-yield facts
Fluoroscopy = real-time dynamic X-ray imaging - essential for cholangiography, fracture fixation, vascular procedures, and guided interventions; use pulsed mode, collimate, and follow ALARA principles to minimise radiation.
FAST positive + haemodynamically unstable = emergency laparotomy; FAST positive + stable = CT abdomen; FAST negative does NOT exclude injury - reassess clinically and consider CT; FAST detects free fluid, not solid organ injury.
Forest plot interpretation: point estimate (effect size), CI crossing 1.0 (significance), I² (heterogeneity), funnel plot (publication bias); OR <1 favours intervention, >1 favours control; I²<25% = safe to pool; symmetrical funnel = no publication bias.
Severe C. difficile = oral vancomycin 125 mg QDS; fulminant = oral vancomycin 500 mg QDS + IV metronidazole; stop causative antibiotics; NO loperamide; soap and water hand hygiene; surgery for toxic megacolon or perforation.
Biliary sepsis = enteric organisms (E. coli, Klebsiella, Enterococcus) ascending from the duodenum - management is antibiotics + urgent biliary drainage (ERCP); Charcot's triad = pain + jaundice + fever; Reynolds' pentad adds confusion + hypotension.
Small bowel = valvulae conniventes (complete folds, central, <3 cm); Large bowel = haustra (incomplete folds, peripheral, <6 cm); 3-6-9 rule for dilatation thresholds; CT is the gold standard for obstruction workup.
NICE NG232 CT head within 1 hour: GCS <13 initial, GCS <15 at 2 hrs, open/depressed fracture, basal skull signs, post-traumatic seizure, focal deficit, >1 vomit; within 8 hours: anticoagulant/bleeding disorder (regardless), or loss of consciousness/amnesia plus age ≥65, dangerous mechanism, or >30 min retrograde amnesia.
Severe contrast reaction = anaphylaxis protocol - IM adrenaline 500 µg first-line; steroids and antihistamines are adjuncts only; premedication for patients with previous reactions; low-osmolality contrast reduces but does not eliminate risk.
Paediatric Surgical Principles
58 high-yield facts
oesophageal foreign body or button battery in the oesophagus = urgent removal; asymptomatic gastric coin = observe and repeat radiograph; sharp/magnetic objects or non-progressing batteries = endoscopic removal.
Bilious vomiting in neonate = volvulus until proven otherwise; upper GI contrast confirms; emergency Ladd procedure; delay risks midgut necrosis.
NEC = pneumatosis intestinalis; medical management first (NBM, antibiotics, TPN); surgery for perforation or deterioration; breast milk protective.
Paediatric inguinal hernia = indirect, patent processus; herniotomy (no mesh); no spontaneous resolution; early repair to avoid incarceration.
Hypospadias = ventral meatus, hooded foreskin, chordee; repair at 6-18 months; preserve foreskin for reconstruction.
PUV = most common congenital urethral obstruction in males; catheterise first; cystoscopic ablation; monitor renal function long-term.
Hepatoblastoma = under 3 years, elevated AFP, liver mass; neoadjuvant chemo then resection; AFP monitors response; transplant if unresectable.
SUFE = obese adolescent, external rotation, referred knee pain; frog-lateral X-ray; in-situ screw fixation; AVN risk especially in unstable slips.
Holliday-Segar = 100/50/20 mL/kg/day; use isotonic fluids in children; avoid hypotonic solutions (hyponatraemia risk); add dextrose to prevent hypoglycaemia.
Paediatric pain = paracetamol + ibuprofen ± local anaesthetic; avoid codeine <12 years and aspirin <16; use age-appropriate pain scoring.
Gillick competence = child can consent if understands; child's refusal can be overridden by parent/court; 16-17 can consent but refusal overridable; 18 = full autonomy.
The GOJ is at approximately 40cm from the incisors - Barrett's oesophagus is columnar metaplasia above the GOJ, classified by the Prague system and surveilled with the Seattle biopsy protocol.
The four FAST windows are RUQ (Morison's pouch), LUQ (splenorenal), suprapubic (pelvic), and subxiphoid (pericardial) - a positive FAST in an unstable patient mandates emergency laparotomy.
The recurrent laryngeal nerve lies in the tracheo-oesophageal groove posterior to the thyroid - it is at greatest risk at the ligament of Berry and must be identified during thyroidectomy.
The tragal pointer is the key landmark for the facial nerve trunk - the nerve is approximately 1cm deep and inferior to this point, and the marginal mandibular branch is the branch most at risk.
AAST Grade IV renal injury involves collecting system laceration with urinary extravasation - delayed-phase CT is essential for diagnosis, and most can be managed non-operatively with ureteric stenting.
The thoracoacromial trunk divides into four PACK branches - the pectoral branch is the dominant supply to pectoralis major, making it the key pedicle for pectoralis major flap reconstruction in head and neck surgery.
The arcuate line marks where the posterior rectus sheath ends - below it, only transversalis fascia lies posterior to the rectus; the inferior epigastric artery enters at this level.
The outer red-red zone of the meniscus has blood supply and healing potential - tears here should be repaired when possible, while avascular white-white zone tears require partial meniscectomy.
The trigone with both ureteric orifices and the internal urethral meatus is the key cystoscopic landmark - observing ureteric efflux confirms ureteric patency and is essential for tumour assessment.
The transversalis fascia forms the posterior wall of the inguinal canal - Lichtenstein mesh reinforces this layer, and the ilioinguinal nerve must be identified to prevent chronic pain.
The posterior approach to the glenohumeral joint targets the inferior-middle humeral head junction - MR arthrography improves detection of labral and partial-thickness rotator cuff tears.
Posterolateral thoracotomy divides latissimus dorsi and serratus anterior - the long thoracic nerve on serratus anterior is at risk, and injury causes scapular winging.
A filling defect on IOC indicates a retained CBD stone - IOC confirms biliary anatomy and reduces bile duct injury risk, and the critical view of safety is the key technique for preventing bile duct injury.
At L1 level on axial CT, the coeliac trunk and SMA origins, pancreas, adrenal glands, and upper kidneys are the key structures to identify.
The right main bronchus is wider, shorter, and more vertical - this explains why foreign body aspiration preferentially affects the right lung, particularly the right lower lobe.
The basal ganglia level on axial CT shows the caudate, lentiform nucleus (putamen and globus pallidus), internal capsule, and thalamus - hypertensive bleeds commonly affect the putamen via lenticulostriate arteries.
On midline sagittal MRI, the corpus callosum is the dominant white matter structure - pituitary tumours cause bitemporal hemianopia by compressing the optic chiasm superiorly.
The left brachiocephalic vein and thymus lie behind the manubrium - in redo-sternotomy, the right ventricle adherent to the posterior sternum is at significant risk of injury.
The right paratracheal stripe should be ≤4mm - widening raises suspicion of paratracheal lymphadenopathy, and the aortopulmonary window should be concave on PA CXR.
The right ventricle forms the anterior cardiac surface - it is the chamber most at risk in penetrating anterior chest trauma and the first chamber encountered during emergency sternotomy.
The great saphenous vein passes anterior to the medial malleolus and drains into the common femoral vein at the SFJ - the small saphenous vein passes posterior to the lateral malleolus and drains into the popliteal vein.
The central line tip should lie at the cavoatrial junction (approximately 2cm below the carina on CXR) - too high risks thrombosis and malposition, too low risks arrhythmias and tamponade.
Complete colonoscopy is confirmed by identification of the appendiceal orifice and ileocaecal valve - the caecal intubation rate is a key quality indicator with a target of ≥95%.
Glass >2mm is radio-opaque and visible on plain X-ray - wooden and organic foreign bodies are radiolucent and require ultrasound for detection.
The right upper lobe bronchus has three segmental bronchi (apical, posterior, anterior) - it is the first lobar branch on the right and a common site for central lung tumours.
HCC derives >90% of blood supply from hepatic arteries, unlike normal liver (75% portal venous) - TACE selectively targets the tumour-feeding artery, and variant hepatic arterial anatomy must be identified pre-procedure.
Calot's triangle = CHD medially + cystic duct inferiorly + liver edge superiorly - the critical view of safety requires only the cystic duct and artery entering the gallbladder before clipping.
A posterolateral disc prolapse compresses the traversing root (numbered one below the disc level) - at L4/L5 this is the L5 root, causing foot drop and dorsal foot sensory loss.
The coeliac trunk gives off the left gastric, splenic, and common hepatic arteries - variant hepatic arterial anatomy is present in approximately 40% of patients and must be identified pre-operatively.
The ileocolic artery is the most constant branch of the SMA - acute SMA occlusion causes pain disproportionate to examination findings with progressive metabolic acidosis.
The single most reliable way to distinguish an intratesticular from an extratesticular mass on ultrasound is demonstrating that the lesion lies within the tunica albuginea - solid intratesticular masses are cancer until proven otherwise (BAUS guidance).
The superficial inguinal nodes drain the lower limb, perineum, and lower abdominal wall - sentinel lymph node biopsy guides staging and management of melanoma with Breslow thickness >1mm.
Modified radical neck dissection preserves the SCM, IJV, and spinal accessory nerve - the spinal accessory nerve is the most functionally important, and its sacrifice causes significant shoulder disability.
The aortic bifurcation lies at the level of the umbilicus (L4) - the inferior epigastric vessels on the posterior rectus sheath are at risk during lateral port placement and should be identified by transillumination.
The CFA is punctured over the femoral head at the mid-inguinal point - puncture above the inguinal ligament risks retroperitoneal haemorrhage, and below the bifurcation risks pseudoaneurysm.
The pulmonary trunk bifurcates beneath the aortic arch at T4-T5 level - a saddle embolus at this bifurcation is a life-threatening finding, and RV/LV ratio >1.0 on CT indicates significant right heart strain.
A Colles fracture shows dorsal displacement of the distal radius with a dinner-fork deformity - Smith is volar displacement, Monteggia is proximal ulna with radial head dislocation, and Galeazzi is distal radius with DRUJ disruption.
The intercostal neurovascular bundle runs along the inferior rib border (VAN) - always insert the needle over the superior border of the lower rib to avoid vascular and nerve injury.
NG tube position is confirmed by the tip lying below the diaphragm in the stomach on CXR - bronchial misplacement is a potentially fatal complication, and CXR confirmation is mandatory before first use.
The infrapatellar branch of the saphenous nerve is the nerve most commonly injured during knee arthroscopy - the anteromedial portal should be created under direct vision to avoid meniscal and neurovascular injury.
A midline laparotomy through the linea alba is avascular and does not divide muscle - below the arcuate line the posterior rectus sheath is absent, and the transversalis fascia is the only layer before the peritoneum.
The PLC comprises the supraspinous and interspinous ligaments, ligamentum flavum, and facet capsules - its disruption indicates instability; the SLIC score guides management of subaxial cervical injuries.
The levator ani is the deepest pelvic floor muscle divided in APR - the presacral venous plexus posteriorly and the urethra anteriorly are critical structures at risk.
The tentorium cerebelli separates the cerebellum from the cerebral hemispheres - the tentorial notch allows passage of the brainstem; posterior fossa tumours are the commonest brain tumours in children.
Right hemicolectomy ligates the ileocolic, right colic, and right branch of the middle colic arteries - the right ureter and duodenum are critical posterior relations at risk during mobilisation.
The normal conus terminates at L1/L2 in adults - termination below L3 suggests tethered cord; conus lesions cause lower motor neuron bladder and bowel dysfunction.
The splenorenal ligament contains the splenic vessels and the pancreatic tail - division must avoid pancreatic injury, and post-splenectomy patients require lifelong vaccination and antibiotic prophylaxis.
The pancreatic tail lies anterior to the left renal hilum - the left renal vein receives the adrenal and gonadal veins and crosses anterior to the aorta below the SMA.
The RLN is at greatest risk at the ligament of Berry where it enters the larynx - a non-recurrent laryngeal nerve (right side only) is associated with an aberrant right subclavian artery.
Three nerves at risk during submandibular gland excision are the marginal mandibular (superficial), lingual (deep), and hypoglossal (deep) - the lingual nerve loops under the submandibular duct.
The cricothyroid membrane between the thyroid and cricoid cartilages is the emergency airway access site - the scalpel-bougie technique is recommended by DAS for 'can't intubate, can't oxygenate' scenarios.
Choroid plexus is in the lateral, third, and fourth ventricles - CSF flows from ventricles to subarachnoid space and is absorbed by arachnoid granulations into the superior sagittal sinus.
The safe triangle boundaries are pectoralis major anteriorly, latissimus dorsi posteriorly, and the nipple line inferiorly - insert over the superior border of the lower rib to avoid the neurovascular bundle.
The IJV lies anterolateral to the carotid artery in the carotid sheath - ultrasound guidance is mandatory (NICE TA49), and the right side is preferred for the most direct SVC route.
The rooftop incision provides the widest upper abdominal exposure - it can be extended superiorly as a Mercedes-Benz incision, and the superior epigastric arteries require ligation bilaterally.
The left adrenal vein drains into the left renal vein, while the right adrenal vein drains directly into the IVC - the short right adrenal vein is a common source of surgical haemorrhage.
Emergency anterolateral thoracotomy is in the left 5th intercostal space - it provides access for pericardiotomy, internal cardiac massage, aortic cross-clamping, and hilum control.
The appendicular artery arises from the ileocolic artery and is an end artery - the appendix base is found at the convergence of the three taeniae coli on the posteromedial caecal wall.
normal upper limits: small bowel 3cm, large bowel 6cm, caecum 9cm. Caecal diameter exceeding 9cm indicates impending perforation risk, particularly in large bowel obstruction with a competent ileocaecal valve.
The upper outer quadrant contains the most glandular breast tissue and is the commonest site for breast cancer - lymphatic drainage is predominantly to the axillary nodes.
Solid hypoechoic nodules with microcalcifications, irregular margins, and taller-than-wide shape are U5 (highly suspicious) - fine needle aspiration is mandatory for cytological assessment.
The VUJ is the narrowest point of the ureter and the most common site for stone impaction - CT KUB is the gold standard investigation for ureteric colic.
The presacral hypogastric nerves on the sacral promontory are at greatest risk during posterior TME dissection - nerve-sparing technique preserves urinary and sexual function.
The aortic arch branches from right to left are brachiocephalic trunk, left common carotid, and left subclavian - a bovine arch variant is present in approximately 20% of patients.
In the mid-pelvis on axial CT, the rectum lies posterior to the bladder or uterus, with the obturator internus and levator ani muscles forming the pelvic walls and floor.
The foramina of Monro connect lateral ventricles to the third ventricle - in obstructive hydrocephalus, the site of obstruction determines the pattern of ventricular dilatation.
The left hilum is normally higher than the right - hilar masses cause enlargement and increased density, and unilateral hilar prominence should raise suspicion of bronchogenic carcinoma.
The ICA has no branches in the neck and has a dilated bulb at its origin - the ECA's multiple branches are the key angiographic distinguishing feature.
The inferior pulmonary veins define the middle-lower oesophageal junction - the oesophagus has three narrowings at C6, T4-T5, and T10, which are common sites for pathology.
Stanford Type B dissection (descending aorta only) is managed medically unless complicated - Type A (ascending aorta involvement) requires emergency surgery, with mortality increasing 1-2% per hour.
Lymphoedema is caused by impaired lymphatic drainage of protein-rich fluid - post-axillary clearance lymphoedema occurs in 15-25% and predisposes to recurrent cellulitis and rarely lymphangiosarcoma.
G cells in the gastric antrum produce gastrin - it stimulates acid secretion directly and via ECL cell histamine release, and negative feedback occurs when antral pH drops below 2 (somatostatin from D cells).
multimodal analgesia = multiple drugs targeting different pain pathway points, reducing opioid requirements. Regular paracetamol + NSAIDs + local anaesthetic technique ± opioid rescue is the standard ERAS approach.
hyperacute = preformed antibodies (minutes), prevented by crossmatching; acute = T-cell or antibody-mediated (days-months), treatable; chronic = fibrosis and vasculopathy (months-years), poorly treatable and commonest cause of late graft loss.
Suppressed TSH + elevated T4/T3 = thyrotoxicosis; elevated TSH + low T4 = primary hypothyroidism; sick euthyroid has low T3 with non-thyroidal illness.
The axon hillock has the lowest threshold and initiates action potentials - the axon conducts them, and compression causes conduction block.
Sodium influx causes depolarisation - hyperkalaemia depolarises resting potential and reduces excitability, and local anaesthetics block Na+ channels.
Calcium triggers exocytosis - botulinum toxin blocks SNARE proteins and prevents ACh release, and neurotransmitter action is terminated by reuptake or enzymatic breakdown.
M2 causes bradycardia, M3 causes bronchospasm - antimuscarinics block neostigmine side effects, and nicotinic receptors are at the NMJ.
Noradrenaline is the main postganglionic sympathetic transmitter - tricyclics potentiate it, and dopamine has renal and emetic effects.
One motor neurone plus its fibres = motor unit - recruitment order follows size principle, and hand muscles have small units for precision.
Myosin power stroke pulls actin - calcium exposes binding sites via troponin, and ATP is required for cross-bridge detachment.
Type I = slow, oxidative, fatigue-resistant - Type II = fast, powerful, fatigable, and distribution varies by muscle function.
Phosphocreatine is the fastest ATP source - glycolysis covers short bursts and oxidative phosphorylation powers endurance, while ischaemic ATP loss drives the rhabdomyolysis of compartment syndrome.
Denervation causes atrophy and ACh supersensitivity - suxamethonium risk of hyperkalaemia, and early reinnervation improves outcome.
T cells = cell-mediated immunity; B cells = antibodies - immunosuppression targets T cell activation.
The portal system delivers hypothalamic releasing hormones to the anterior pituitary without systemic dilution - the posterior pituitary receives direct neuronal input, and pituitary surgery risks disrupting both systems.
GH causes insulin resistance and lipolysis - acromegaly is associated with diabetes; GH pulses occur during sleep; IGF-1 mediates growth effects.
Prolactin is under tonic dopaminergic inhibition - dopamine antagonists cause hyperprolactinaemia; cabergoline treats prolactinomas; prolactin suppresses GnRH causing hypogonadism.
Thyrotoxic patients risk thyroid storm perioperatively - optimise beta-blockers and antithyroid drugs; in emergency, give propranolol, carbimazole, consider iodine; avoid sympathomimetics.
Hypothyroidism causes bradycardia via reduced beta-adrenergic sensitivity - also causes cold intolerance, slowed metabolism; perioperatively consider sedation sensitivity and hypothermia.
Calcitonin inhibits bone resorption and lowers calcium - PTH raises calcium; vitamin D increases absorption; calcitonin has limited role in adults.
Primary hyperparathyroidism = elevated PTH + hypercalcaemia from adenoma - surgery is curative; PTHrP from malignancy suppresses PTH.
Secondary HPT in CKD = hypocalcaemia, hyperphosphataemia, low 1,25-D - parathyroids hypertrophy; treat with phosphate binders, vitamin D, calcimimetics.
Exogenous steroids are the commonest cause - endogenous: pituitary adenoma (Cushing disease) most common; diagnose with UFC, dexamethasone suppression.
Aldosterone increases Na⁺ reabsorption and K⁺/H⁺ excretion in the distal nephron - stimulated by angiotensin II and hyperkalaemia; ACE inhibitors reduce aldosterone production, while spironolactone blocks the mineralocorticoid receptor (NICE NG106).
Phaeochromocytoma = elevated metanephrines - alpha-blockade before surgery; rule of 10s; never beta-block before alpha-blockade.
The hypothalamus is the body's thermostat - anaesthesia blunts it, so warm the patient actively during prolonged surgery (NICE CG65).
Liver (primary) and kidney (prolonged fasting) perform gluconeogenesis; substrates are lactate, glucogenic amino acids and glycerol; muscle lacks glucose-6-phosphatase; glucagon/cortisol stimulate, insulin inhibits (CPOC perioperative fasting guidance).
Glucagon and adrenaline stimulate glycogenolysis - insulin inhibits.
Fasting drives lipolysis to release FFAs and hepatic ketogenesis to fuel the brain; unopposed, this same pathway causes the ketoacidosis of DKA (JBDS).
Early starvation = glycogenolysis first, then rising ketogenesis after glycogen depletion; prolonged fasting shifts metabolism toward fat and ketone use - minimise fasting per ERAS/NICE perioperative nutrition principles.
Refeeding syndrome = insulin-driven intracellular shift of phosphate, potassium and magnesium - feed slowly, give thiamine and replace electrolytes (NICE CG32).
Catabolic = proteolysis > synthesis (cortisol, catecholamines, sepsis); anabolic = synthesis > breakdown (insulin, IGF-1, recovery). Negative nitrogen balance signals catabolism - minimise with ERAS principles and early nutritional support per NICE CG32.
RANKL activates osteoclasts, OPG inhibits them - denosumab (anti-RANKL antibody) is used to treat osteoporosis by blocking osteoclast differentiation.
adaptive immunity is defined by specificity, diversity, memory, and self-tolerance - vaccination exploits immunological memory to provide protection without causing disease.
zinc is a cofactor for over 300 metalloenzymes - deficiency causes acrodermatitis, poor healing, dysgeusia, and immune dysfunction. High-output stomas are a common surgical cause of zinc depletion.
critically ill patients need 1.2-2.0g/kg/day protein - nitrogen balance is calculated from protein intake ÷ 6.25 minus urinary urea nitrogen plus insensible losses.
μ receptor = analgesia + respiratory depression + constipation + nausea. Morphine is a full μ agonist. UK ERAS/NICE NG193 promote multimodal opioid-sparing analgesia to reduce ileus, PONV and chronic opioid use.
True shunt blood bypasses ventilated alveoli entirely and is refractory to supplemental O2 - PEEP recruits collapsed alveoli to reduce shunt, and the shunt equation (Qs/Qt) quantifies the proportion of shunted blood.
Alveolar PO2 is approximately 13.3kPa on room air at sea level - the alveolar gas equation calculates PAO2, and the A-a gradient assesses the efficiency of gas exchange (normal <2kPa).
Monro-Kellie - total intracranial volume is constant (brain 80%, blood 10%, CSF 10%) - initial volume increases are compensated by CSF displacement, but once exhausted, ICP rises exponentially with further small volume changes.
Propofol causes hypotension through vasodilation and myocardial depression - etomidate is the induction agent of choice for haemodynamically unstable patients, and ketamine has sympathomimetic effects that may support blood pressure.
The MMC is the fasting intestinal housekeeper sweeping debris and bacteria distally every 90-120 minutes - it is mediated by motilin, abolished by feeding, and disruption predisposes to small bowel bacterial overgrowth.
Conjugated bilirubin is water-soluble and appears in urine (dark urine) - obstructive jaundice shows raised conjugated bilirubin with pale stools (absent stercobilin) and dark urine (bilirubinuria).
Haemodialysis primarily uses diffusion for solute removal and convection for fluid removal - peritoneal dialysis uses the peritoneum as a natural semipermeable membrane, and hypertonic dialysate provides the osmotic gradient for ultrafiltration.
Normal osmolality is 275-295mOsm/kg, calculated as 2(Na) + glucose + urea - sodium is the major determinant of tonicity, and both hyper- and hyponatraemia must be corrected gradually to avoid neurological injury.
Group O Rh-negative is the universal donor because red cells lack A, B, and D antigens - ABO-incompatible transfusion causes acute intravascular haemolysis, and the most common cause of fatal transfusion reactions is administrative error (wrong blood given to the wrong patient).
ABPI <0.5 = critical ischaemia requiring urgent vascular referral - NEVER apply compression to an arterial ulcer, and NEVER elevate an ischaemic limb.
Glutamine synthetase in astrocytes converts ammonia to glutamine causing osmotic swelling - this is the mechanism of cerebral oedema in hepatic encephalopathy, and lactulose reduces ammonia absorption by acidifying the colonic lumen.
A-delta = fast sharp first pain (myelinated); C = slow burning second pain (unmyelinated); prostaglandin sensitisation explains NSAID efficacy; gate control and descending modulation underpin TENS, tramadol, duloxetine, and amitriptyline per NICE NG193.
ARAS and cortex/thalamus maintain consciousness - GCS ≤8 = coma; brainstem lesions cause arousal failure.
Tertiary HPT = autonomous PTH after long-standing secondary HPT - often post-renal transplant; may need parathyroidectomy; watch for hungry bone syndrome.
Catecholamines increase HR, contractility, vasoconstriction - stimulate glycogenolysis and lipolysis.
SIRS = hypermetabolic, catabolic state with raised energy expenditure, hyperglycaemia, muscle proteolysis (negative nitrogen balance) and lactic acidosis; cytokine and stress-hormone driven; per NICE NG51/SSC, early enteral feeding and glucose 6-10 mmol/L.
RQ = VCO₂/VO₂. Carbohydrate ~1.0, protein ~0.8, fat ~0.7, mixed diet 0.8-0.85. RQ >1.0 = lipogenesis/overfeeding (more CO₂, harder to wean); RQ <0.7 = ketosis/starvation. Use indirect calorimetry per NICE CG32 / ESPEN to guide ICU nutrition.
TXA inhibits fibrinolysis - blocks plasminogen; give early in trauma; reduces mortality in CRASH-2.
MAC = pore formation, cell lysis - complement deficiencies increase Neisseria risk; three pathways converge at C3.
ALARA = As Low As Reasonably Achievable; minimise dose using time, distance, and shielding, as required under IR(ME)R 2017 and IRR17.
Iron absorbed in duodenum - hepcidin regulates ferroportin; inflammation increases hepcidin.
Type I = sliding (95%, GORD); Type II = paraesophageal (GOJ in situ, fundus herniates - risk of volvulus); Type III = mixed; Type IV = other organs herniate; Cameron ulcers cause iron deficiency anaemia; Types II-IV usually require surgical repair.
APR = permanent end colostomy; indicated for low rectal cancer involving the sphincter; ELAPE provides wider margins than standard APR; neoadjuvant CRT is standard for T3/4 or N+ rectal cancer; perineal wound complications are common (20-40%); MERCURY study validated MRI for CRM prediction.
Symptomatic severe AS = surgical indication; syncope/angina/HF; asymptomatic if LV dysfunction or exercise symptoms; median survival poor without intervention.
Gangrene = vascular assessment; revascularise if possible; primary amputation if not reconstructable.
Gastrografin is both diagnostic (contrast in caecum by 24h = resolution) and therapeutic (osmotic effect reduces oedema); reduces hospital stay; not a substitute for surgery when strangulation or peritonitis present; administer at 24 hours per Bologna guidelines.
Elective THR → LMWH 28 days or DOAC 28-35 days plus mechanical prophylaxis (NICE NG89); TKR = 14 days; aspirin alone is not first-line.
Adult femoral shaft fracture → reamed antegrade intramedullary nail within 24-36 h (BOAST, NICE NG37); plate for periprosthetic; external fixation only as damage-control; LMWH VTE prophylaxis (NICE NG89).
Painless haematuria + smoking/occupational exposure = suspect bladder cancer; flexible cystoscopy is gold standard; CT urogram for upper tracts; TCC >90% of bladder cancers; 2-week wait referral for visible haematuria >45 years.
Gustilo II = 1-10 cm wound; IIIB = needs flap; IIIC = vascular injury; higher grade = more debridement, delayed closure.
Graves definitive = radioiodine or surgery; surgery for large goitre, pregnancy plan, ophthalmopathy; prepare euthyroid pre-op.
Hartmann procedure = sigmoid resection + end colostomy + rectal stump closure; safest option in septic/unstable patients with faecal peritonitis; reversal only achieved in 40-60%; primary anastomosis with loop ileostomy is an alternative in stable patients; LADIES trial informs decision-making.
Shunt malfunction = most common complication; obstruction at proximal end; enlarged ventricles on CT; urgent revision; infection = S. epidermidis, remove shunt.
Linear fracture = observe; depressed >1 cm or compound = surgery; growing fracture in children; always CT for intracranial pathology.
CTA = anatomy for planning; assess calcification, runoff; caution in renal impairment.
Early laparoscopic cholecystectomy within 72 hours (up to 1 week) is best practice per NICE; always achieve the critical view of safety; percutaneous cholecystostomy for patients unfit for surgery; subtotal cholecystectomy if anatomy unclear.
Mirizzi syndrome = stone impacted in GB neck compressing the CHD; Csendes Types I-V; Type I = extrinsic compression (cholecystectomy); Types II-IV = fistula (bile duct reconstruction); high risk of bile duct injury at surgery.
Male breast cancer = mastectomy + axillary staging; often ER+; tamoxifen for adjuvant hormonal therapy.
Carotid intervention within 2 weeks of TIA/stroke; early intervention = greater benefit.
Raynaud = lifestyle, CCB if needed; exclude secondary causes; sympathectomy for severe ulceration.
TOS = neurogenic or vascular; physio first; surgery if refractory.
Renal artery stenosis = stop ACEi if bilateral; revascularise for flash pulmonary oedema, refractory HTN.
Elective TKR per NICE NG89 = LMWH or DOAC (rivaroxaban/apixaban) for 10-14 days, plus mechanical prophylaxis. Extended prophylaxis (28-35 days) is for total hip replacement. Always document a VTE/bleeding risk assessment.
Vascular MDT = surgeons, IR, diabetes, podiatry; revascularisation vs amputation decisions.
Pulmonary contusion = delayed radiographic changes (6-24 hours); CT more sensitive; supportive care; restrict fluids; ventilate if severe; most lethal chest injury.
Traumatic aortic injury = isthmus, deceleration; widened mediastinum on CXR; CT aortogram to confirm; TEVAR or open repair; control BP.
Boerhaave = Mackler triad (vomiting, chest pain, emphysema); contrast swallow or CT; early surgical repair; delay = high mortality.
Thoracotomy for >1500 mL initial or >200 mL/hr ongoing; tamponade; resuscitative thoracotomy for penetrating cardiac arrest; best survival in penetrating cardiac injury.
CABG for left main stem, triple-vessel with low EF, diabetics; LIMA-LAD has best patency; SYNTAX score guides PCI vs CABG; risks include stroke and mediastinitis.
IE surgery for heart failure, uncontrolled infection, large vegetation with emboli; S. aureus left-sided = high mortality; early surgery improves outcomes.
SAH = thunderclap headache; berry aneurysm 85%; CT then CTA; coiling preferred over clipping; nimodipine for vasospasm; LP if CT negative.
Prolactinoma = cabergoline first (even macroadenoma); non-functioning = surgery; GH = surgery then octreotide; pituitary apoplexy = emergency.
Intradural extramedullary = meningioma/schwannoma; surgical excision; intramedullary = ependymoma/astrocytoma; extradural = metastases most common overall.
NPH = wet, wobbly, wacky; CSF tap test predicts shunt response; VP shunt is definitive; gait improves first; obstructive hydrocephalus = EVD/ETV urgently.
CSF leak = beta-2 transferrin positive; conservative initially; most resolve in 7-10 days; surgery if persistent; meningitis risk; antibiotics not routine.
NEXUS/Canadian rules guide clearance; CT if criteria not met; plain films insufficient; MRI for persistent concern in obtunded patients.
Spinal abscess with neurology = emergency surgery + IV antibiotics 6-8 weeks; S. aureus most common; diabetes/IVDU risk; outcome depends on pre-op neurology.
Nerve repair within 72 hours; epineural microsurgical technique; nerve graft for gaps; regeneration 1 mm/day; younger and distal = better prognosis.
Cubital tunnel = ulnar nerve at elbow; decompression ± transposition; clawing, Froment sign, Wartenberg sign; second most common entrapment.
Trigeminal neuralgia = lancinating facial pain, triggered; carbamazepine first-line; MRI to exclude secondary; MVD for refractory with best long-term outcomes.
Anterior dislocation = Bankart common; reduce, sling; surgery if recurrent.
Colles = dorsal (FOOSH, dinner-fork); Smith = volar; Barton = intra-articular fracture-dislocation; ORIF for unstable/intra-articular; always assess median nerve and bone health (BOAST 2020; NOGG; NICE NG226).
Weber A below / B at / C above the syndesmosis; A usually stable; B depends on stability (talar shift, medial injury); C usually needs ORIF plus syndesmotic fixation (BOAST Ankle Fracture 2016).
Osteomyelitis = IV antibiotics; surgery if abscess or no response; Staph most common.
Achilles rupture is a clinical diagnosis (positive Simmonds-Thompson test); both functional rehabilitation and surgery are valid, and modern functional bracing has narrowed the re-rupture difference (UKSTAR trial), so surgery is reserved for athletes, late presentation or re-rupture.
Cervical disc = ACDF or arthroplasty; posterior foraminotomy for lateral.
De Quervain = first dorsal compartment release; Finkelstein test; splintage/steroid first.
A graft needs a vascularised bed; exposed bone, tendon, cartilage or metalwork needs a flap. Open lower-limb fractures should be managed jointly by orthoplastic teams (BOAST 4 / BOA-BAPRAS Open Fractures standards; NICE NG37).
Free flap = microvascular; latissimus, ALT for limb; large defects when local insufficient.
Rule of nines for rapid adult estimation, Lund-Browder for accuracy and in children, and palm ≈ 1% TBSA; assess depth by appearance, sensation and capillary refill, then resuscitate using the Parkland formula.
Tangential excision and split-thickness skin grafting is for deep dermal and full-thickness burns; excise to a viable bleeding bed and graft; early excision (within ~3-5 days) lowers infection and improves outcomes.
Electrical = cardiac monitor; myoglobinuria; compartment syndrome; deep damage.
Frostbite = rapid rewarming 37-39°C; no rubbing; delay debridement until demarcation.
Stones <5 mm = conservative management; MET with tamsulosin for 5-10 mm distal stones; urgent intervention for sepsis, bilateral obstruction, or solitary kidney; follow-up imaging at 2-4 weeks.
Recurrent stones = 24-hour urine collection + stone analysis; hypercalciuria most common metabolic abnormality; fluid intake >2.5 L/day; thiazides for hypercalciuria; potassium citrate for hypocitraturia.
Ureteroscopy = gold standard for ureteric stones failing conservative management; holmium laser for fragmentation; JJ stent commonly placed; high stone-free rates; ESWL alternative for proximal stones.
PCNL for renal stones >20 mm and staghorn calculi; complete clearance essential for struvite; treat infection pre-operatively; complications include bleeding, sepsis, pneumothorax; stone-free rates 75-95%.
RASS -3 = moderate sedation (movement/eye opening to voice, no eye contact). Target RASS 0 to -2 for most ICU patients. Lighter sedation reduces ventilation days and delirium. The correct answer is C.
RCRI six factors - high-risk surgery, IHD, CHF, CVD, insulin-dependent diabetes, creatinine >177μmol/L; age and sex are NOT included; ≥3 factors indicate >9-15% risk of major cardiac events (Lee 1999; NICE NG45).
4 METs (one flight of stairs) is the key threshold - patients unable to achieve 4 METs have increased perioperative cardiac risk and may require further cardiac investigation before major surgery.
Withhold ACE inhibitors, ARBs, and NSAIDs on the day of surgery and ensure adequate hydration - these are the most important preoperative measures to reduce AKI risk in high-risk patients with pre-existing CKD.
Child-Pugh C (score 10-15) carries 50-80% perioperative mortality for abdominal surgery and is generally a contraindication to elective procedures - MELD >15 also indicates high surgical risk.
LMWH starting 6-12 hours postoperatively for 28-35 days (hip) or 14 days (knee) is NICE-recommended VTE prophylaxis for major orthopaedic surgery - extended prophylaxis beyond discharge is critical.
Routine MBP alone does not reduce anastomotic leak or SSI and may cause harm - MBP combined with oral antibiotics may reduce SSI; MBP is still indicated for rectal surgery and when intraoperative colonoscopy is planned.
ERAS integrates preoperative optimisation, minimally invasive surgery, multimodal analgesia, early nutrition, and early mobilisation - opioid-sparing analgesia is a cornerstone; programme success requires audit and compliance monitoring.
NICE NG45 recommends targeted preoperative testing based on ASA grade, comorbidities, and surgical complexity - healthy ASA I patients undergoing minor surgery need no routine blood tests; unnecessary testing generates false positives and delays.
Preoperative ECG is indicated for patients with cardiovascular disease, diabetes, or renal disease undergoing intermediate/major surgery - healthy patients undergoing minor surgery do not need routine ECG; age alone is not an indication.
RSI minimises aspiration risk through pre-oxygenation, cricoid pressure, rapid-onset NMB, and avoidance of mask ventilation - suxamethonium or high-dose rocuronium (with sugammadex available) are used; the goal is rapid airway securing.
Spinal anaesthesia causes sympathetic blockade - vasodilation and reduced venous return cause hypotension; block of T1-T4 cardiac accelerator fibres causes bradycardia; treat with fluids, vasopressors (ephedrine/phenylephrine), and atropine for bradycardia.
Axillary block is best for hand/forearm surgery targeting terminal branches - the safest approach with lowest complication rate; interscalene for shoulder; supraclavicular for arm/elbow; musculocutaneous nerve must be blocked separately with axillary approach.
Lidocaine: 3mg/kg plain, 7mg/kg with adrenaline; bupivacaine: 2mg/kg maximum; prilocaine 6mg/kg plain - always calculate dose, account for injection site vascularity, and avoid adrenaline in end-artery territories.
Moderate sedation = purposeful response to verbal commands + spontaneous ventilation + maintained airway; sedation depth is a continuum and can deepen unpredictably - full monitoring and resuscitation equipment are mandatory.
Procedural sedation uses midazolam+fentanyl, propofol, or ketamine - capnography is recommended for all procedural sedation; the sedationist and proceduralist must be separate individuals; full monitoring and resuscitation equipment are mandatory.
Day surgery requires medical fitness (ASA I-III stable), suitable procedure, and appropriate social circumstances including a responsible adult for 24 hours - age and BMI alone are not exclusion criteria; target day surgery rate >75% for suitable procedures.
NCEPOD Immediate = within minutes, life/limb/organ saving - resuscitation is simultaneous with preparation; Urgent = hours; Expedited = days; Elective = planned; NELA data shows emergency laparotomy carries ~10% 30-day mortality overall.
Adrenaline IM 0.5mg or IV 50mcg boluses is first-line for anaphylaxis - NAP6 identified NMBs as the most common trigger; take tryptase at 0, 1-2hrs, and >24hrs; refer to allergy clinic at 6 weeks.
Medication reconciliation creates an accurate medication list at every care transition to prevent errors - up to 70% of patients have discrepancies at admission; verify from multiple sources; document perioperative holding and restart plans clearly.
Prolonged lithotomy risks lower limb compartment syndrome - reduced perfusion pressure from elevation plus reperfusion injury on lowering; >4 hours is a significant risk factor; emergency fasciotomy is required if diagnosed.
Steep Trendelenburg reduces FRC by diaphragm displacement - exaggerated with obesity and pneumoperitoneum; risks include raised ICP/IOP, facial/airway oedema, and brachial plexus injury; check for cuff leak before extubation after prolonged head-down position.
Surgical smoke contains carcinogens, viable HPV DNA, and ultrafine particles - exposure equivalent to 27-30 cigarettes/day; evacuate with local exhaust within 2cm of source; FFP2/N95 masks minimum; standard surgical masks are insufficient.
Inadvertent hypothermia is core temperature <36°C - coagulopathy, SSI, arrhythmias, and delayed recovery; NICE mandates active warming for procedures >30 minutes, prewarming if <36°C, and theatre temperature ≥21°C; forced air warming is most effective.
Arterial puncture is the most common acute CVC complication - ultrasound guidance (NICE mandatory for IJV) reduces risk by >50%; confirm tip position with CXR; Trendelenburg position prevents air embolism; internal jugular is preferred site.
PA catheter thermodilution is the gold standard for cardiac output - declining use due to complications and lack of mortality benefit; oesophageal Doppler and arterial waveform analysis are preferred for GDFT in surgery; CVP does NOT reliably predict fluid responsiveness.
Catheterise for prolonged surgery (>2-3 hours), pelvic surgery, need for urine output monitoring, and lithotomy position - avoid unnecessary catheterisation (CAUTI risk 3-7% per day); ERAS recommends early removal within 24 hours; HOUDINI mnemonic guides removal decisions.
Routine drain use after colorectal anastomosis is not supported by evidence and is not recommended by ERAS - drains may be justified for haemostasis concerns, low pelvic anastomosis, and pancreatic surgery; remove early when output is minimal.
Target SpO2 88-92% in COPD/hypercapnic risk patients (BTS guidelines); 94-98% for all others - excessive oxygen causes CO2 retention in COPD; oxygen is a drug that must be prescribed; hyperoxia is harmful and worsens outcomes in MI and stroke.
Multimodal analgesia combines agents from different classes (paracetamol, NSAIDs, regional, gabapentinoids, opioids as rescue) - synergistic effect with reduced side effects; opioid-sparing is a core ERAS principle; regular dosing is superior to PRN.
PCA safety relies on the patient self-limiting their use through sedation (negative feedback) - only the patient should press the button; no background infusion in opioid-naive adults; monitor sedation score, RR, and SpO2; PCA by proxy has caused deaths.
POUR with bladder volume >500mL requires catheterisation - common after spinal anaesthesia especially with intrathecal morphine; TWOC in 24-48 hours; risk factors include male sex, BPH, opioids, and pelvic surgery; alpha-blockers may aid successful TWOC.
Atelectasis is the commonest cause of early postoperative fever - prevention with incentive spirometry, early mobilisation, and adequate analgesia; treat with chest physiotherapy and CPAP if needed; bronchoscopy reserved for refractory lobar collapse.
SSI prevention bundle: antibiotic within 60 minutes, normothermia >36°C, glycaemic control 6-10mmol/L, chlorhexidine-alcohol skin prep, clippers not razors - prolonged postoperative antibiotics do not reduce SSI and promote resistance.
CVC care bundle: hand hygiene, full barrier precautions, chlorhexidine prep, optimal site, daily review for removal - Matching Michigan reduced CLABSI by 60%; routine line changes are NOT recommended; subclavian has the lowest infection rate.
Duty of candour: inform the patient promptly, give a truthful account, apologise (not admission of liability), offer support, and provide written notification - statutory requirement after the Francis Report; CQC monitors compliance; failure is a criminal offence for organisations.
APACHE II = Acute Physiology Score (12 variables) + Age points + Chronic Health points - scored ONCE within the first 24 hours of ICU admission using worst values. SOFA tracks organ failure daily; APACHE II predicts hospital mortality at admission (FICM/ICNARC).
Non-rebreathing mask at 15 L/min = highest FiO2 non-invasively (~85-90%). For precise FiO2 delivery, use a Venturi mask. Always investigate the underlying cause of hypoxia.
HFNO = Heated + Humidified + High-flow (up to 60 L/min) + low-level PEEP + dead space washout. It bridges the gap between conventional oxygen and non-invasive ventilation. Monitor closely for failure.
BiPAP = two pressures (IPAP + EPAP) = ventilation support = type 2 respiratory failure. CPAP = one pressure = oxygenation support = type 1 respiratory failure/pulmonary oedema.
High-risk ICU patients need BOTH pharmacological (LMWH or UFH) AND mechanical (IPC devices) thromboprophylaxis. Start within 24 hours. GCS alone and aspirin alone are insufficient. Reassess daily for contraindications.
Target glucose 6-10 mmol/L in ICU patients (NICE-SUGAR). Avoid tight glycaemic control (Leuven target 4.4-6.1 associated with more hypoglycaemia and higher mortality). Hypoglycaemia kills - moderate control is safer than tight control.
CAM-ICU = gold standard for ICU delirium screening (NICE CG103; PADIS 2018). Features: acute/fluctuating + inattention + (disorganised thinking OR altered consciousness). Prevent with the ABCDEF bundle; avoid benzodiazepines.
NPWT + fascial traction = highest fascial closure rates (70-90%). Aim for closure within 7-10 days. Bogota bag is simple but low closure rates. Never force closure under tension - risks ACS recurrence.
Second-look laparotomy = planned at 24-48 hours when bowel viability is uncertain. The decision is made at the FIRST operation, not based on clinical deterioration. Key in mesenteric ischaemia and damage control surgery.
UK brainstem death preconditions = known irreversible aetiology + apnoeic coma on ventilator + exclude hypothermia, drugs, metabolic and circulatory causes. Two suitably qualified doctors, two complete sets of tests. EEG NOT required (AoMRC Code of Practice 2008/2024).
DNACPR = applies to CPR ONLY, not other treatments. Patients with capacity can make their own decision. Decisions should be reviewed regularly. A DNACPR patient can still have surgery, antibiotics, and active treatment.
Necrotising fasciitis = clinical diagnosis + EMERGENCY radical debridement. Do NOT delay for imaging. Broad-spectrum antibiotics + clindamycin (antitoxin). Re-look debridement at 24-48 hours. Early surgery saves lives (UK Sepsis Trust; RCS England).
Evisceration = DO NOT reduce at bedside + warm saline packs over bowel + supine with knees flexed + analgesia + emergency theatre. Never use dry gauze on exposed bowel. Cover, protect, and operate urgently.
Perioperative hypothermia (<36°C) = increased SSI + impaired coagulation + increased blood loss + cardiac risk + prolonged recovery. Prevent with forced-air warming + IV fluid warmers + warm theatre. NICE CG65 mandates active warming.
5% dextrose provides free water and calories; use with caution in hyponatraemia or cerebral oedema risk.
Insensible losses must be replaced even when NBM; failure leads to hypernatraemia and dehydration.
Peripheral IV potassium maximum 10 mmol/hour and 40 mmol/L (BNF/NICE NG29); central line with cardiac monitoring is needed for faster rates; always check and replace magnesium; never bolus undiluted potassium chloride.
In hyperkalaemia with ECG changes, give IV calcium first to protect the heart, then insulin-dextrose ± salbutamol to shift potassium into cells, and arrange dialysis for removal (UK Kidney Association: Treatment of Acute Hyperkalaemia in Adults; Resuscitation Council UK).
Correct magnesium in refractory hypokalaemia and before treating hypocalcaemia; magnesium protects against torsades.
Vomiting = metabolic alkalosis; diarrhoea = metabolic acidosis. Alkalosis is maintained by hypovolaemia and hypokalaemia.
Crystalloids distribute to ECF; ~25% stays intravascular. Use for resuscitation and maintenance; monitor for oedema with large volumes.
Crystalloids are first-line; colloids have limited evidence of benefit. Avoid starch in sepsis and renal failure.
5% dextrose = free water + glucose; use for maintenance when NBM; avoid in hyponatraemia and hypovolaemic shock.
4-2-1 rule for maintenance: 100 mL/kg for first 10 kg, 50 mL/kg for next 10 kg, 20 mL/kg for rest.
Third space = sequestered fluid in tissues; replace cautiously; excessive crystalloid worsens oedema and ileus.
Enteral preferred when gut works; preserves mucosal barrier, reduces infection. PN when enteral impossible or inadequate.
TPN when gut unusable or inadequate; assess nutritional risk. Avoid if enteral feasible. Start when anticipated duration >5-7 days.
Start slowly in malnourished patients; replace phosphate, K+, Mg2+; give thiamine. Monitor closely for refeeding syndrome.
Immunonutrition = arginine, omega-3, nucleotides; consider in high-risk GI surgery. Give 5-7 days pre-op.
Consent = capacity + voluntary + informed. Document the discussion. Montgomery: disclose material risks patient would consider significant.
Gillick competence = child's understanding of treatment. Competent under-16s can consent; parental consent also valid.
Bolam = standard of care (responsible body of opinion); Bolitho = that opinion must be logical; Montgomery = patient-centred consent (material risks); causation must also be proved for negligence to succeed.
Unexplained or inconsistent injuries in children = consider NAI. Discuss with paediatrics. Follow safeguarding procedures.
Diverticular bleeding = most common cause of major lower GI haemorrhage in elderly. Bleeding often from right-sided diverticula. Vasa recta erosion is the mechanism. Stops spontaneously in 80%.
NET grading: G1 = Ki-67 <3%, G2 = Ki-67 3-20%, G3 = Ki-67 >20% (well-differentiated). NEC = poorly differentiated, very high Ki-67. Ki-67 is the key grading parameter. Synaptophysin and chromogranin A are diagnostic markers. Functioning vs non-functioning based on hormone production.
Epidermoid = granular layer + lamellated keratin + punctum (anywhere). Pilar = no granular layer + homogeneous keratin + no punctum (scalp, AD). Dermoid = skin appendages inside (embryological fusion sites). 'Sebaceous cyst' is a misnomer - most are epidermoid or pilar.
Post-splenectomy blood film = Howell-Jolly bodies + target cells + acanthocytes + Pappenheimer bodies + thrombocytosis + lymphocytosis - these are permanent features confirming absent splenic function.
Biofilm on prosthetic surface prevents antibiotic and immune access → graft excision usually required. S. epidermidis (early), S. aureus (later). Aortoenteric fistula: herald bleed → massive GI haemorrhage (secondary to graft erosion into duodenum). Graft infection mortality is 25-75%.
Vulnerable plaque = thin cap, large necrotic core, intraplaque haemorrhage → highest stroke risk. Artery-to-artery embolism is the main stroke mechanism. CEA for symptomatic stenosis >50% within 2 weeks. Echolucent plaques on duplex = higher risk.
PD-1/PD-L1 and CTLA-4 are immune checkpoints. Nivolumab/pembrolizumab = anti-PD-1. Ipilimumab = anti-CTLA-4. Remove 'brakes' on T cells → anti-tumour immunity. irAEs = autoimmune-like side effects (colitis, thyroiditis, hepatitis). MSI-high CRC responds to pembrolizumab.
Myeloma = purely lytic lesions (RANKL/MIP-1α activates osteoclasts, DKK1 inhibits osteoblasts). Negative bone scan (no osteoblastic activity). CRAB criteria for diagnosis. Bence Jones proteinuria. >10% plasma cells on marrow. Raindrop skull on X-ray.
IVIg is the fastest way to raise platelets preoperatively in ITP - it works within 24-72 hours by blocking Fc-mediated platelet destruction, buying a safe surgical window.
Lipoma red flags = size >5 cm, deep to fascia, rapid growth, firm and fixed - refer urgently to a sarcoma service via NICE NG12.
DIC = consumptive coagulopathy driven by tissue factor - treat the cause (surgical source control), replace what is consumed (platelets, cryo, FFP), and monitor with the ISTH DIC score.
Ferritin <15 µg/L is virtually diagnostic of iron deficiency, but ferritin is an acute phase protein and may be falsely normal in inflammation - always interpret alongside TIBC and transferrin saturation.
The terminal ileum is the sole site of B12 absorption - any resection exceeding 60 cm necessitates lifelong parenteral B12 replacement to prevent irreversible neurological damage.
A safe prescribing mnemonic for G6PD-deficient patients is to avoid the 'NDPS' drugs - Nitrofurantoin, Dapsone, Primaquine, and Sulphonamides - and always check G6PD status before prescribing rasburicase.
Haematocrit <0.45 is the critical preoperative target in PV - venesect before elective surgery and ensure adequate hydration perioperatively to prevent life-threatening thrombosis.
Factor VIII dose = 0.5 × weight × desired rise; Factor IX dose = 1.0 × weight × desired rise - always check for inhibitors before surgery as they render standard factor replacement ineffective.
Pseudo-Pelger-Huët cells are the hallmark blood film finding of MDS - bilobed neutrophils with pancytopenia in an elderly patient should prompt haematology review and bone marrow biopsy for definitive diagnosis.
Leukoerythroblastic film + teardrop cells + pancytopenia = bone marrow infiltration until proven otherwise - always request a trephine biopsy (not just aspirate) and reconsider the surgical plan pending haematological diagnosis.
Stored red cells lose 2,3-DPG (leftward shift = poor oxygen delivery) and leak potassium - 2,3-DPG regenerates within 24-48 hours after transfusion; beware hyperkalaemia in massive transfusion and neonatal patients.
Platelet thresholds: <10 = prophylactic transfuse; >50 for most invasive procedures; >100 for neurosurgery/ophthalmic - platelets stored at 20-24°C, shelf life 5-7 days; contraindicated in TTP and HIT.
Rivaroxaban/apixaban reversal = andexanet alfa; dabigatran reversal = idarucizumab; heparin = protamine; warfarin = PCC + vitamin K - if specific agents unavailable, give PCC 50 IU/kg for DOACs.
ITP and hereditary spherocytosis are the commonest elective splenectomy indications - always vaccinate 2 weeks pre-op, combine with cholecystectomy if gallstones present, and plan lifelong penicillin V prophylaxis.
Post-emergency splenectomy vaccines at 2 weeks: Pneumovax + Prevenar, MenACWY, MenB, and Hib - plus lifelong penicillin V, annual flu vaccine, medical alert card, and patient education about OPSI risk.
Non-operative management + angioembolisation is the gold standard for haemodynamically stable splenic injuries - save the spleen whenever safely possible; splenectomy is reserved for haemodynamic instability or failure of NOM.
The key event is premature trypsinogen → trypsin conversion within the pancreas; trypsin then activates all other zymogens causing autodigestion; GET SMASHED mnemonic for causes; severity stratified by revised Atlanta 2012 / modified Glasgow per BSG 2021 guideline.
SMA embolism is the #1 cause (50%) - usually from AF. Pain out of proportion to examination is the classic early finding. Lactate elevation is a late sign indicating established ischaemia.
Massive splenomegaly = CML, myelofibrosis, chronic malaria, kala-azar, Gaucher disease. The mnemonic is 'Really Massive Spleens Can Kill' - CML, Myelofibrosis, Malaria, Kala-azar, Gaucher.
Post-operative pneumonia = atelectasis + impaired cough + retained secretions. Upper abdominal surgery has highest risk. Prevention: early mobilisation, incentive spirometry, adequate analgesia, physiotherapy. Pre-operative smoking cessation reduces risk.
CKD anaemia = reduced erythropoietin production (normocytic normochromic). Key surgical concerns: hyperkalaemia (ECG + correct K⁺), uraemic coagulopathy, infection risk. Protect the AV fistula arm. Check potassium immediately pre-operatively.
Calcium oxalate = most common (70-80%), radio-opaque. Uric acid = radiolucent, form in acid urine. Struvite = infection stones, alkaline urine, staghorn. Cystine = inherited, hexagonal crystals. All stones visible on CT KUB.
P fimbriae = pyelonephritis (bind renal epithelium), Type 1 fimbriae = cystitis (bind bladder epithelium). Adhesion is the critical first step. CAUTI risk increases ~5%/day - remove catheters early. E. coli causes 80% of community UTIs.
Communicating hydrocele = patent processus vaginalis (varies in size). Treat with herniotomy if persistent beyond age 2. Adult hydroceles: exclude underlying testicular pathology with ultrasound. Lord's or Jaboulay procedure for adults.
Cord ends at L1/L2 → below this is cauda equina (LMN, peripheral nerve roots). CES = saddle anaesthesia + bladder dysfunction + bilateral leg symptoms. Urinary retention is often the first sign. Emergency MRI and decompression - delay causes permanent damage.
Vertebral metastases = most common cause of MSCC. Breast, lung, prostate, kidney, thyroid are the top primaries. Thoracic spine most affected. Back pain + UMN signs + sensory level = MSCC until proven otherwise. Give dexamethasone immediately, urgent MRI.
Haematoma → inflammation → soft callus (cartilage) → hard callus (woven bone) → remodelling (lamellar bone). This is secondary healing with callus. Primary healing (no callus) only with rigid fixation. Smoking, NSAIDs, and infection impair healing.
Pannus = proliferative synovium eroding cartilage and bone (MMPs + osteoclasts). TNF-α is key cytokine (target of biologic therapies). C1/C2 instability must be assessed before anaesthesia. RA is a systemic disease - always consider extra-articular features.
Dermoid = ectodermal tissue trapped at embryological fusion lines. Contains skin appendages (hair, sebaceous glands). External angular (lateral eyebrow) = most common. Midline nasal - ALWAYS image to exclude intracranial extension before surgery. Attached to periosteum.
KA = 'rapid growth then involutes' but is histologically indistinguishable from well-differentiated SCC on small biopsies. Treat as SCC - excision with clear margins. Volcano-like appearance with keratin crater. Excision biopsy (not punch) needed for accurate diagnosis.
Rule of nines: arm 9%, anterior trunk 18%, posterior trunk 18%, leg 18%, head 9%, perineum 1%. Lund-Browder is more accurate (especially for children). Parkland formula: 4 mL × kg × %TBSA. Half in first 8 hours from time of burn. Fluid resuscitation for >15% TBSA (adults).
The sequence is ischaemia → ATP → hypoxanthine + xanthine oxidase → reperfusion → superoxide → H₂O₂ → hydroxyl radical (via Fenton). Superoxide from xanthine oxidase is the initial species.
Dystrophic = abnormal tissue + normal calcium. Metastatic = normal tissue + abnormal calcium. Mammographic microcalcifications in DCIS are dystrophic, forming in areas of comedo necrosis.
Virchow's triad = endothelial injury + stasis + hypercoagulability; all three elements operate post-operatively. Major orthopaedic surgery is highest risk (40-70% VTE without prophylaxis).
Class III shock = 30-40% loss = tachycardia + hypotension + confusion + oliguria. Shock classification is fundamental ATLS knowledge. Hypotension appears in Class III when compensatory mechanisms are overwhelmed.
DIC = systemic coagulation activation → widespread microthrombosis → consumption of factors/platelets → secondary fibrinolysis → bleeding. D-dimers elevated + low fibrinogen + low platelets + prolonged PT/APTT is the diagnostic constellation. Treat the underlying cause.
VWD = commonest inherited bleeding disorder. VWF bridges platelets to collagen (primary haemostasis) and carries factor VIII (secondary haemostasis). Type 1 = partial deficiency, treat with DDAVP. Prolonged bleeding time + prolonged APTT = VWD until proven otherwise.
Type IV = T cell-mediated (no antibodies) = delayed (48-72 hours). CD4+ T cells + macrophages are the key effectors. Contact dermatitis and the Mantoux test are classic examples. Patch testing is diagnostic.
Intestinal TB = ileocaecal + transverse ulcers + caseating granulomas + strictures. Crohn = any site + longitudinal ulcers + non-caseating granulomas + skip lesions. ADA elevated in TB ascites. Surgery only for complications.
Tetanospasmin → retrograde axonal transport → blocks glycine/GABA release from Renshaw cells → unopposed motor activity → spasm. Toxoid vaccine for prevention. HTIG for post-exposure prophylaxis in high-risk wounds. Trismus (lockjaw) is the classic presenting feature.
MRSA = mecA gene → PBP2a (altered penicillin-binding protein) → resistance to ALL beta-lactams. Carried on SCCmec. Different from beta-lactamase which destroys the drug. Treat with vancomycin, linezolid, or daptomycin.
C. difficile = Toxin A (enterotoxin) + Toxin B (cytotoxin) → mucosal damage + pseudomembranes. Does NOT invade tissue. Risk factors = antibiotics + age + hospitalisation + PPIs. Fulminant colitis with toxic megacolon requires emergency subtotal colectomy.
Transplant recipients = 65-250x increased SCC risk. BCC:SCC ratio reverses. Impaired immune surveillance + HPV. SCC has metastatic potential (2-5%). Actinic keratosis = precursor. Marjolin ulcer = SCC in chronic wound/scar. Keratin pearls on histology.
GBM = most common primary malignant brain tumour in adults. IDH wild-type + microvascular proliferation + pseudopalisading necrosis = WHO grade 4. Ring enhancement on MRI. Stupp protocol: surgery + TMZ/RT → adjuvant TMZ. MGMT methylation predicts TMZ response. Median survival 14-16 months.
Midgut carcinoid syndrome requires liver metastases (first-pass metabolism); flushing + diarrhoea + bronchospasm + right-sided valvulopathy; diagnose with 24-hour urinary 5-HIAA; treat per ENETS/UKINETs with somatostatin analogues; cover anaesthesia with octreotide to prevent carcinoid crisis.
Cetuximab = anti-EGFR monoclonal antibody. Only works in K-RAS wild-type CRC (test RAS status first). Acneiform rash is an on-target effect (correlates with response). Bevacizumab = anti-VEGF, trastuzumab = anti-HER2, imatinib = anti-KIT.
Cancer cachexia ≠ simple starvation - not fully reversible with nutrition alone. TNF-α + IL-6 + tumour-derived factors drive inflammation + proteolysis + lipolysis. GPS (CRP + albumin) predicts surgical outcomes. Sarcopenia = independent predictor of poor outcomes.
Type II = IgG/IgM antibodies against cell surface antigens → complement + ADCC → cell destruction. HDN = maternal IgG anti-RhD crosses placenta → fetal red cell destruction. Prevention = anti-D prophylaxis at 28 weeks and post-delivery.
ZES = gastrinoma → acid hypersecretion → ulcers + diarrhoea + steatorrhoea. Gastrinoma triangle. 60% malignant. 25% associated with MEN 1. Fasting gastrin >1000 + secretin stimulation test diagnostic. PPIs control symptoms; surgery for localised disease.
Graves = stimulatory IgG anti-TSH receptor antibodies = type II hypersensitivity (stimulatory variant). Unlike most type II reactions which are destructive, Graves antibodies stimulate the target cell. Thyrotoxicosis + exophthalmos + pretibial myxoedema is the classic triad.
Smoking = #1 modifiable risk for bladder cancer (50% of cases). Urothelial carcinoma >90% in the West. Schistosoma → SCC in endemic areas. Non-muscle-invasive → TURBT + BCG. Muscle-invasive → radical cystectomy. Check for detrusor muscle in TURBT specimen to confirm staging adequacy.
Pre-splenectomy: vaccinate ≥2 weeks before (Pneumococcus, Meningococcus, Hib, influenza). Post-splenectomy: lifelong penicillin V + carry card + urgent antibiotics for fever. OPSI = 50-70% mortality. S. pneumoniae is the most common pathogen. Vaccinate 2 weeks post-op if emergency splenectomy.
Aromatase inhibitors = block androgen-to-oestrogen conversion in peripheral tissues. Post-menopausal only (pre-menopausal = tamoxifen). Side effects: arthralgia + osteoporosis. Monitor DEXA. Tamoxifen = SERM, used pre-menopausal, risk of endometrial cancer + VTE.
Consider IV fluids before release if possible. Monitor potassium; treat hyperkalaemia. Alkalinise urine (bicarbonate) to reduce myoglobin precipitation. Mannitol is sometimes used. Dialysis may be needed. Compartment syndrome can also develop.
ATLS does not require complete diagnosis before treatment - it mandates 'treat as you find' with constant reassessment. The primary survey, resuscitation, secondary survey, and definitive care form the four pillars of the ATLS approach.
Tension pneumothorax is one of the immediately life-threatening conditions identified during 'B' of the primary survey - diagnose clinically, treat immediately, confirm later.
The two key thoracotomy indications for haemothorax: >1500 mL immediate drainage OR >200 mL/hour for 2-4 hours. Both indicate ongoing surgical bleeding requiring operative control.
Pericardiocentesis is a temporising, not definitive, procedure in traumatic tamponade. Aim towards the left shoulder from the subxiphoid position. Emergency thoracotomy is the definitive approach.
The 1:1:1 ratio is the standard of care in massive transfusion protocols. Group O Rh-negative blood is used initially until crossmatched blood is available. Warm all products to prevent hypothermia.
Pelvic binder at greater trochanter level - this is a common MRCS examination point. The binder is the first step, not external fixation or surgery.
Pan-scan is indicated in significant mechanism + haemodynamically stable. Unstable patients go to theatre, not CT. The 'donut of death' teaching emphasises that haemodynamically unstable patients should not be in the CT scanner.
AMPLE history should be obtained from the patient, relatives, or paramedics. Warfarin and DOACs are critical medications that change trauma management - always ask about anticoagulants.
'Resuscitate before you relocate' - but don't use stabilisation as an excuse to delay time-critical transfer. The transfer decision involves balancing stabilisation against the urgency of definitive intervention.
Rule of Nines for adults, Lund and Browder chart is more accurate (especially children). Only include partial and full-thickness burns in TBSA calculation - do NOT include superficial/erythema-only burns.
Primary blast injury affects air-filled structures due to the pressure differential. Blast lung presents with the triad of apnoea, bradycardia, and hypotension. Positive pressure ventilation may worsen air embolism - use low tidal volumes and permissive hypercapnia.
DAI = coma out of proportion to CT findings. MRI is more sensitive. Three key locations: grey-white junction, corpus callosum, brainstem. There is no surgical treatment - management is supportive with prevention of secondary brain injury. Prognosis depends on grade and age.
EDT survival: cardiac stab ~35%, thoracic penetrating ~15%, abdominal penetrating ~5%, blunt <2%. Time limits: penetrating <15 min CPR, blunt <10 min CPR.
Left anterolateral approach - 5th intercostal space. Open pericardium anterior to the phrenic nerve. The aortic cross-clamp is applied to the descending thoracic aorta against the vertebral body.
Standard lab tests warm the sample to 37°C and will NOT detect hypothermic coagulopathy. Core temperature <34°C = significant coagulopathy. Active rewarming is essential - the lethal triad demands simultaneous correction of hypothermia, acidosis, and coagulopathy.
The lethal triad = hypothermia + acidosis + coagulopathy. Breaking this cycle is the primary goal of damage control resuscitation. Once fully established, mortality exceeds 50%.
CRASH trial = steroids harm TBI. Target CPP 60-70 mmHg. ICP target <20-22 mmHg. Never aggressively hyperventilate. Mannitol requires serum osmolality monitoring (stop if >320 mOsm/kg). Hypertonic saline is an alternative first-line osmotic agent.
FIBTEM MCF reflects fibrinogen contribution to clot strength. Low FIBTEM = give fibrinogen (cryoprecipitate or concentrate). EXTEM MCF reflects fibrinogen + platelets. Low EXTEM MCF with normal FIBTEM = give platelets. ROTEM guides goal-directed transfusion, reducing waste.
Shock index = HR/SBP. Normal = 0.5-0.7. Values >0.9 predict massive transfusion need. Values >1.0 = significant shock. It is more sensitive than blood pressure alone as a triage and assessment tool.
The 'platinum 10 minutes' concept - scene time should ideally be <10 minutes for critical trauma. Transport to MTC, not nearest hospital. Perform only life-saving interventions en route.
START triage is for MASS CASUALTY sorting, not individual patient assessment. A patient who breathes only after airway intervention = T1 (Immediate). Walking wounded = T3 (Delayed). Mental status failure = T1 (Immediate).
Unstable spine + cord compression + incomplete deficit = urgent surgery. The STASCIS trial suggested that early surgery (<24 hours) may improve outcomes by at least 2 ASIA grades. Mean arterial pressure should be maintained ≥85 mmHg for 7 days (spinal cord perfusion).
Gold = Strategy (remote HQ), Silver = Tactics (near scene), Bronze = Operations (at scene). Each service has its own command hierarchy. JESIP principles: Co-locate, Communicate, Co-ordinate, Jointly understand risk, Shared situational awareness.
METHANE is for scene reporting in major incidents. It should be sent as early as possible, even with incomplete information - update as more details become available. All emergency services use the same METHANE format under JESIP.
QuikClot Combat Gauze (kaolin) = current standard haemostatic agent. Pack wound tightly, apply direct pressure for 3+ minutes. Junctional haemorrhage = pack with haemostatic gauze when tourniquets can't be applied.
MILS during intubation is the standard of care for suspected cervical spine injury. Remove the front of the collar to allow mouth opening while maintaining MILS. Video laryngoscopy reduces cervical movement compared to direct laryngoscopy. A GCS of 4 mandates definitive airway.
ROTEM-guided therapy: prolonged CT = FFP/PCC. Low EXTEM MCF + normal FIBTEM MCF = platelets. Low FIBTEM MCF = fibrinogen (cryoprecipitate/concentrate). Increased ML = TXA for fibrinolysis. Goal-directed therapy reduces blood product use and improves outcomes.
<32°C = moderate hypothermia, <30°C = severe. Severe hypothermia requires active core rewarming. Avoid rough handling - VF risk. Consider bypass/ECMO for cardiac arrest. 'You're not dead until you're warm and dead.'
TXA within 3 hours = beneficial. After 3 hours = potentially harmful. Earlier = better. Dose: 1g IV over 10 minutes + 1g IV over 8 hours. Prehospital administration is the goal. The CRASH-3 trial extended TXA evidence to traumatic brain injury.
Track the lactate trend, not just the initial value. Clearance >20% at 6 hours = good prognosis. Failure to clear = reassess for ongoing bleeding, missed injury, or inadequate resuscitation. Target lactate normalisation (<2 mmol/L) within 24 hours.
Kaolin = activates intrinsic pathway (needs functioning clotting factors). Chitosan = directly cross-links RBCs (works independently of clotting cascade, potentially advantageous in coagulopathic patients). Both require wound packing with direct pressure.
In austere surgery: pack and go. Control haemorrhage (packing), control contamination (staple bowel), temporary closure, resuscitate, return later. The ICRC War Surgery manual emphasises these principles for resource-limited settings.
GCS ≤8 = intubate. The purpose is twofold: airway protection AND control of PaCO2 (target 4.5-5.0 kPa) to prevent secondary brain injury. Avoid hyperventilation (PaCO2 <4.0 kPa) which causes cerebral vasoconstriction and ischaemia.
Raccoon eyes = anterior fossa fracture. Battle sign = middle fossa/petrous fracture. CSF leak = dural tear. Nasopharyngeal airways are CONTRAINDICATED in suspected base of skull fracture. Most CSF leaks resolve spontaneously within 7-10 days.
Ipsilateral fixed dilated pupil + contralateral hemiplegia = uncal herniation until proven otherwise. This is a neurosurgical emergency requiring urgent surgical decompression. The pupil on the side of the lesion dilates first (same side as the haematoma).
Refer early, not when the patient is dying. NICE criteria are designed to capture patients who MAY need neurosurgery. The decision to operate rests with the neurosurgeon. GCS ≤8 or deteriorating GCS + CT abnormality = likely operative.
Neurogenic shock ≠ spinal shock. Neurogenic = haemodynamic (hypotension + bradycardia). Spinal shock = neurological (temporary loss of all reflexes below the level). They often coexist but are distinct entities. Always exclude haemorrhage before attributing hypotension solely to neurogenic shock.
AD can cause stroke, seizures, and death if untreated. Bladder distension is the #1 trigger (blocked catheter, UTI). Bowel distension is #2 (constipation, impaction). Always sit the patient up first, then find and fix the trigger. Occurs in injuries at or above T6.
All Le Fort fractures involve the pterygoid plates. Le Fort I = mobile palate, Le Fort II = mobile mid-face (pyramidal), Le Fort III = mobile entire face (craniofacial dissociation).
Lower lip numbness = inferior alveolar/mental nerve injury (sensory, V3). Don't confuse with marginal mandibular nerve (motor, CN VII - lip movement). The mandible is the second most commonly fractured facial bone (after the nasal bone). Condylar fractures are most common overall.
Infraorbital numbness = V2 (maxillary nerve) injury. Zygomatic fracture features: cheek flattening, infraorbital numbness, diplopia, trismus, and epistaxis (maxillary sinus involvement). Surgical fixation is via open reduction internal fixation (ORIF) if displaced.
The three neck zones: Zone I (clavicle to cricoid - great vessels, thoracic duct), Zone II (cricoid to mandible angle - carotid, jugular, larynx, pharynx), Zone III (mandible angle to skull base - distal carotid, pharynx).
BCVI can present with delayed stroke - have a high index of suspicion. Screen with CTA if risk factors are present. Cervical spine fractures through the transverse foramen strongly predict vertebral artery injury. Early antithrombotic therapy reduces stroke risk.
Laryngeal fracture = high-risk airway. Do NOT blindly intubate. Prepare for surgical airway. CT + fibreoptic assessment.
Gunshot wound + unstable + peritonitis = immediate laparotomy. No imaging required for unstable patients - go to theatre. Midline laparotomy provides the best access. Damage control principles apply.
Intraperitoneal rectal injury = treat like colon. Extraperitoneal = diversion is key. The traditional '4 Ds' have been simplified - diversion remains the most important element. Perineal wounds should be debrided and managed with wound care.
Posterior knee dislocation = assume popliteal artery injury until proven otherwise. Check ABPI: <0.9 = investigate (CTA). Warm ischaemia >6 hours = high amputation risk. Always perform fasciotomy after revascularisation. Common peroneal nerve injury also frequent (25-35%).
MESS ≥7 predicts amputation, but it is a guide not a mandate. Ischaemia score doubles after 6 hours - this emphasises the urgency of revascularisation. The MESS has ~100% specificity but lower sensitivity - a low score doesn't guarantee salvage. The decision to amputate is multidisciplinary.
The decision to amputate is not a failure - it can be the best option for long-term function and quality of life. Insensate plantar foot + prolonged ischaemia + severe injury = strong indication for amputation. Patient involvement in the decision is essential.
Stop, drop, and roll first. Then cool the burn with cool running water for 20 minutes. Remove non-adherent clothing and jewellery. Do not use ice.
0.5-1 mL/kg/hour urine output guides burn resuscitation. Titrate fluids to this target. Consider avoiding over-resuscitation (fluid creep).
If in doubt, intubate early in inhalation injury. Airway oedema progresses - a patent airway now may be obstructed in hours. Hoarseness is a warning sign.
Electrical burns = iceberg injury. Bone resistance causes deep heating. Watch for myoglobinuria, compartment syndrome, and delayed vascular complications.
Chemical burns: remove contaminant, irrigate copiously with water first. Neutralisation can cause thermal injury. HF needs calcium gluconate after irrigation.
Alkali = liquefactive necrosis = deeper. Acid = coagulative necrosis = more superficial. Both need copious irrigation.
Blood at meatus = do NOT catheterise. RUG first. Anterior (straddle) vs posterior (pelvic fracture) injuries have different mechanisms and management. Suprapubic catheter is the safe alternative when urethral injury is confirmed.
Curreri: 25 kcal/kg + 40 kcal/% TBSA. High protein. Early enteral feeding. Burns cause massive catabolism.
Tile A = stable. Tile B = rotationally unstable. Tile C = vertically + rotationally unstable. Tile C has highest haemorrhage risk.
Schatzker VI = metaphyseal-diaphyseal dissociation. High energy. Watch soft tissues. May need staged fixation.
Displaced midshaft clavicle = consider fixation. Shortening >2 cm, skin tenting, open = fix. Plate preferred.
4-part + elderly + osteoporosis = reverse TSA. ORIF for younger patients with good bone. Neer = 4 parts, >1 cm or >45° displacement.
Stable fixation, especially intramedullary nailing, of a tibial shaft fracture allows early weight-bearing as tolerated; comminuted patterns or less stable constructs may need protected weight-bearing, and you should always follow the operating surgeon's protocol.
The systematic approach remains ABCDE - treat the greatest threat to life first. Paediatric trauma teams should have age-appropriate equipment immediately available.
Use 0.9% saline or balanced crystalloid. Reassess after each bolus. In haemorrhagic shock, early blood product consideration is appropriate. IO access is acceptable if IV access is difficult.
Operate for haemodynamic instability unresponsive to resuscitation, peritonitis, or associated injuries requiring laparotomy. Damage control surgery with packing may be needed. Most paediatric liver injuries heal without intervention.
Consider non-accidental injury in non-ambulant children. Age-appropriate management: <6 years - spica; 6-11 - flexible nails or spica; >11 - rigid nail (avoiding piriformis fossa in pre-adolescents).
Think NAI when the history doesn't match the injury, there are multiple injuries of different ages, or the child is pre-ambulant. Document meticulously. Safeguarding takes priority over parental rapport.
Maternal survival is the priority. Perimortem caesarean may be considered if the mother is in cardiac arrest and gestation is viable (>24 weeks). Document gestational age and involve obstetrics early.
Consider exploration for deep hand wounds. Infection can develop within 24 hours. Cat scratch disease (Bartonella) is different - from scratches, causes lymphadenopathy. Document and consider rabies if from an unvaccinated cat abroad.
Contained anastomotic leak + stable patient = image-guided drainage first; approaches include transgluteal, transrectal, or percutaneous; surgery reserved for failed drainage, diffuse peritonitis, or haemodynamic instability.
Valid RCT = randomisation + allocation concealment + blinding (where possible) + ITT analysis + adequate power; CONSORT guidelines standardise reporting; surgical trials face unique blinding challenges but can use blinded outcome assessment.
Aminoglycosides = concentration-dependent killing + narrow therapeutic index - monitor trough levels (<1 mg/L for gentamicin), check renal function daily, and limit courses to <7 days where possible.
Give antibiotics within 60 minutes of incision at induction - single dose is usually sufficient; re-dose for operations >4 hours or blood loss >1500 mL; never extend beyond 24 hours postoperatively.
Type I NF = polymicrobial (aerobes + anaerobes, diabetics, perineum/abdominal wall); Type II = monomicrobial (GAS, young/healthy); treatment = emergency radical debridement + broad-spectrum antibiotics; delay = death.
Sestamibi = mitochondria-rich tissue accumulation; parathyroid adenomas retain tracer on delayed imaging while thyroid washes out - sensitivity 80-90% for single adenomas; SPECT-CT improves 3D localisation for minimally invasive parathyroidectomy.
PET-CT = metabolic + anatomical imaging - FDG uptake reflects glucose metabolism (Warburg effect); essential for staging oesophageal, lung, colorectal, and head/neck cancers; detects occult metastases that change surgical management; false positives from inflammation.
Paracetamol toxicity = NAPQI accumulation when glutathione is depleted - NAC replenishes glutathione; give within 8 hours of ingestion; enzyme inducers and malnutrition increase risk; maximum safe dose is 4 g/day (2 g in liver disease).
Adrenaline treats ALL components of anaphylaxis: α1 = vasoconstriction (BP); β1 = cardiac output; β2 = bronchodilation + mast cell stabilisation - give 500 µg IM (1:1000) for anaphylaxis; NEVER use 1:1000 IV (fatal arrhythmias).
PONV risk assessment with Apfel score; multimodal antiemesis for high-risk patients: ondansetron (5-HT3) + dexamethasone (steroid) ± cyclizine (H1) - each additional antiemetic class reduces PONV by approximately 25%.
UFH = antithrombin-dependent anti-Xa and anti-IIa; LMWH = antithrombin-dependent anti-Xa predominant; warfarin = blocks vitamin K factor synthesis; DOACs = direct factor Xa (apixaban/rivaroxaban) or thrombin (dabigatran) inhibition.
CDC wound classes: I Clean (1-2%); II Clean-contaminated (3-10%); III Contaminated (10-20%); IV Dirty (15-40%) - faecal peritonitis is Class IV; consider delayed closure and therapeutic antibiotics for dirty wounds.
S. aureus in multiple blood cultures = true bacteraemia always - treat with prolonged IV antibiotics, get an echocardiogram, identify the source, and repeat cultures to confirm clearance; never dismiss as contamination.
CAUTI management = change/remove the catheter + targeted antibiotics - biofilm on the catheter surface harbours organisms resistant to antibiotics; daily assess catheter necessity; asymptomatic bacteriuria in catheterised patients does NOT need treatment.
Aciclovir = viral TK activation → DNA polymerase inhibition - selective toxicity to infected cells; IV for immunosuppressed patients with VZV; foscarnet for aciclovir-resistant strains; always consider antiviral prophylaxis in immunosuppressed surgical patients.
SBP = monomicrobial (single Gram-negative), cirrhotic ascites, treat with antibiotics only; Secondary peritonitis = polymicrobial (aerobes + anaerobes), surgical cause, REQUIRES operative source control - misdiagnosis is fatal.
Abdominal sepsis = give broad-spectrum IV antibiotics within 1 hour (piperacillin-tazobactam + gentamicin or equivalent); cover Gram-negatives, anaerobes, and Gram-positives; source control surgery is essential alongside antibiotics.
90% of 'penicillin allergic' patients are NOT truly allergic - non-severe reactions (rash only) allow safe cephalosporin use; cross-reactivity is <2%; promote penicillin allergy de-labelling programmes.
S. aureus = the #1 wound pathogen; coagulase creates protective fibrin barriers; treat MSSA with flucloxacillin, MRSA with vancomycin; biofilm formation on prosthetics requires device removal for cure.
MRSA resistance = mecA → PBP2a with low beta-lactam affinity, so it is resistant to ALL beta-lactams - treat with vancomycin/teicoplanin or linezolid, and decolonise with mupirocin plus chlorhexidine before prosthetic surgery.
CRBSI diagnosis = differential time to positivity (CVC culture ≥2 hours before peripheral) or quantitative cultures; S. aureus and Candida CRBSI = always remove the line; CoNS may allow line salvage with antibiotic lock therapy.
CT in pancreatitis = contrast-enhanced at 48-72 hours for optimal necrosis assessment; earlier if diagnostic doubt or clinical deterioration; CT Severity Index guides prognosis; IV contrast is safe and essential for assessment.
MRI = superior soft tissue contrast without radiation - gold standard for perianal fistulae, rectal cancer staging, spinal cord, and musculoskeletal; contraindicated with ferromagnetic implants; slow scan time limits emergency use.
Systematic CXR = RIPE quality check → airway → mediastinum → lungs → pleura → diaphragm → bones/soft tissues → review areas → lines/tubes - never jump to the obvious abnormality without completing the system.
Rifampicin (hepatitis, orange discolouration of body fluids, CYP450 enzyme inducer - reduces efficacy of warfarin, OCP, ciclosporin), Isoniazid (peripheral neuropathy - prevented with pyridoxine/vitamin B6, hepatitis), Pyrazinamide (hepatotoxicity - most hepatotoxic of the four, hyperuricaemia/gout), Ethambutol (optic neuritis - check visual acuity).
Early PJI (<3 months) with well-fixed prosthesis = DAIR + modular exchange + prolonged antibiotics including rifampicin; chronic PJI = two-stage revision (removal → spacer → antibiotics → reimplantation); culture at least 5 intraoperative tissue samples.
ALARA = Time, Distance, Shielding - the cornerstones of radiation safety; pregnant staff can work with radiation provided fetal dose <1 mSv; lead aprons reduce but do not eliminate exposure; inverse square law governs distance protection.
Sensitivity = TP/(TP+FN); Specificity = TN/(TN+FP); PPV = TP/(TP+FP); NPV = TN/(TN+FN); SnNOut (sensitive = rules out); SpPIn (specific = rules in); PPV depends on prevalence - the lower the prevalence, the lower the PPV.
Cephalosporin generations: 1st = Gram-positive; 2nd = balanced (cefuroxime - best for surgical prophylaxis); 3rd = Gram-negative; no standard cephalosporin covers MRSA (only ceftaroline, 5th gen).
Vancomycin = glycopeptide for serious MRSA infections - monitor trough levels (15-20 mg/L for deep infections), infuse slowly to avoid red man syndrome, and watch for nephrotoxicity especially with concurrent aminoglycosides.
Candidaemia = echinocandin first-line (caspofungin); remove CVCs; fluconazole for step-down if sensitive; amphotericin B if resistant - always perform ophthalmology review for endophthalmitis screening.
WHO ladder = Step 1 (paracetamol/NSAID) → Step 2 (add weak opioid) → Step 3 (add strong opioid); modern surgical pain uses multimodal analgesia and may start at Step 3 for major surgery, de-escalating as recovery progresses.
LAST = CNS signs → seizures → cardiac arrest - give 20% lipid emulsion immediately; bupivacaine is the most cardiotoxic LA; know the max safe doses and always aspirate before injecting.
PPIs irreversibly block the H⁺/K⁺-ATPase proton pump - the final common pathway of acid secretion; continue perioperatively; be aware of long-term risks including C. difficile, hypomagnesaemia, and osteoporosis.
Ranitidine withdrawn 2020 due to NDMA contamination (MHRA) - famotidine is the current preferred H2RA; H2RAs are LESS potent than PPIs (competitive, reversible H2 blockade); avoid cimetidine due to drug interactions and anti-androgen effects.
Aspirin = irreversible COX-1 acetylation → no TXA2; Clopidogrel = irreversible P2Y12 ADP receptor blockade - both last 7-10 days (platelet lifespan); ticagrelor is the only reversible P2Y12 inhibitor (offset in 3-5 days).
Steroid cover for major surgery = hydrocortisone 100 mg IV at induction + 50 mg 8-hourly for 48-72 hours; any patient on ≥5 mg prednisolone for >3 weeks needs supplementation; Addisonian crisis presents as refractory hypotension.
Tacrolimus = FKBP12 binding → calcineurin inhibition → blocked IL-2 → suppressed T-cell activation; monitor trough levels; main toxicity is nephrotoxicity; NEVER stop perioperatively without transplant team guidance.
30-60 minutes before incision = optimal prophylaxis timing (at induction); re-dose for long operations (>2 drug half-lives) or major blood loss (>1500 mL); never extend beyond 24 hours postoperatively.
Ultrasound = first-line for biliary, renal, thyroid, vascular, and gynaecological pathology - no radiation, portable, real-time; limitations include obesity, gas/bone, and operator dependence; CT and MRI complement ultrasound for specific indications.
NNT = 1/ARR; always round UP; NNH = 1/ARI; compare NNT vs NNH to assess benefit-harm balance; ARR is more clinically meaningful than RRR; a perfect treatment has NNT = 1.
Seven pillars of clinical governance = clinical effectiveness, audit, risk management, education/training, patient involvement, information management, and staffing - surgeons demonstrate engagement through M&M meetings, national audit participation, incident reporting, and revalidation.
MCA 2005 principles: assume capacity, decision-specific, best interests if incapable; family do NOT have automatic authority; ADRT is legally binding; emergency treatment can proceed under best interests without formal capacity assessment if urgent.
Report ALL incidents (including near misses); duty of candour = statutory legal requirement to inform patients of moderate/severe harm, provide truthful account, and apologise - an apology is NOT an admission of liability; never events must be reported nationally.
IR-guided percutaneous drainage = first-line for most hepatic abscesses - less invasive than surgery with comparable outcomes; surgery for failed IR, multiloculated collections, or associated pathology requiring operative management.
The audit cycle = standard → measure → compare → change → re-audit (close the loop); without re-audit, it's just data collection; audit ≠ research - audit measures against known standards, research generates new knowledge.
CTA = gold standard for acute mesenteric ischaemia - SMA filling defect + bowel non-enhancement + portal venous gas = embolism; SMA embolism is commonest (50%, AF); mortality >60% - early CTA and surgery save lives.
Opioid toxicity triad = respiratory depression + sedation + pinpoint pupils - give naloxone IV titrated to respiratory rate; naloxone has a shorter half-life than most opioids so re-dosing may be needed; avoid large boluses to prevent withdrawal and pain crisis.
Quinolone adverse effects = tendinopathy (Achilles rupture), QT prolongation, neuropathy, aortic dissection, and drug interactions - restrict use per MHRA guidance; avoid in patients >60 on steroids; always check QTc and concurrent medications.
Clarithromycin = potent CYP3A4 inhibitor - NEVER combine with simvastatin (rhabdomyolysis risk); azithromycin is safer for drug interactions; erythromycin has a unique prokinetic role via motilin receptor agonism.
Metronidazole = anaerobic specialist activated by electron transport in anaerobic bacteria → DNA damage; causes disulfiram-like reaction with alcohol (avoid for 48 hours); potentiates warfarin - essential in any regimen targeting intra-abdominal anaerobes.
NSAIDs reduce renal perfusion by blocking prostaglandin-mediated afferent vasodilation - avoid perioperatively in renal impairment, hypovolaemia, or with ACE inhibitors/diuretics; also impair platelet function and increase GI bleeding risk.
Cat bites → Pasteurella multocida (rapid onset, deep inoculation); dog bites → Pasteurella + Capnocytophaga; human bites → Eikenella; first-line = co-amoxiclav for all bite wounds; always assess tendon and joint involvement in hand bites.
Evidence hierarchy: systematic review > RCT > cohort > case-control > case series > expert opinion; RCTs minimise bias through randomisation; surgical RCTs face unique challenges (blinding, learning curve); always critically appraise methodology, not just the study type.
Wilson and Jungner = 10 criteria for screening; AAA screening exemplifies these perfectly; key elements include important condition, detectable latent phase, acceptable test, effective treatment, and cost-effectiveness; MASS trial provided the evidence base.
Tonsillectomy = 7/1, 5/2, or 3/3 documented episodes; OSA is major indication; secondary haemorrhage at day 5-10.
Epistaxis = first aid → anterior packing → posterior packing → sphenopalatine ligation; correct anticoagulation; never cauterise both sides.
Nasal FB = attempt removal with hook/suction; button battery = emergency; ear FB = irrigation if non-organic and TM intact; ENT for failed removal.
Branchial cyst = anterior SCM, young adult, cholesterol crystals; excise to prevent infection; >40 years = exclude malignancy.
Persistent lymphadenopathy >6 weeks + B symptoms = urgent biopsy; excision biopsy for lymphoma; FNA/core for metastatic cancer; 2WW pathway.
Hard neck lump in smoker = SCC until proven otherwise; USS-FNA + panendoscopy; never open biopsy first; 2WW pathway.
Hoarseness >3 weeks in smoker = 2WW; microlaryngoscopy and biopsy; CT/MRI staging; early glottic = radiotherapy; advanced = chemoRT or laryngectomy.
Tracheostomy for prolonged ventilation, airway obstruction, protection, weaning; benefits = comfort, less sedation, speech; percutaneous preferred in ICU.
Displaced tracheostomy = remove tube, cover stoma, ventilate via mouth; follow NCEPOD algorithm; late complications include tracheal stenosis and innominate artery fistula.
Facial repair = irrigate, layered closure, fine sutures, early removal 3-5 days; check facial nerve and parotid duct; align landmarks precisely.
TOF = Type C most common (85%); NG tube coils in pouch; gas in stomach = distal fistula; primary repair; screen VACTERL.
Pleomorphic adenoma = superficial parotidectomy, preserve facial nerve; no enucleation (recurrence); Frey syndrome post-op; risk of malignant transformation.
Orchidopexy by 12 months; laparoscopy for impalpable testis; increased malignancy and infertility risk if untreated.
Ranula = sublingual gland mucous cyst; bluish floor of mouth swelling; excision of sublingual gland is definitive; plunging ranula extends into neck.
Choledochal cyst = excise completely with Roux-en-Y; malignancy risk if left; internal drainage contraindicated.
Caustic ingestion = do not induce vomiting or lavage; early endoscopy; alkali worse than acid; long-term stricture and cancer risk.
NAI = mechanism inconsistent with developmental stage; bruising in a pre-mobile child must be explained; skeletal survey under 2 years; statutory safeguarding referral is mandatory.
Torus = buckle, stable, splint 3 weeks; greenstick = incomplete break, may need manipulation; both unique to paediatric bone.
Gastroschisis = right of umbilicus, no membrane, fewer anomalies; omphalocele = midline, membrane, chromosomal associations; both need surgical closure.
VUR = prophylactic antibiotics; low-grade often resolves; surgery for persistent high-grade, breakthrough infections, or progressive scarring.
Biliary atresia = conjugated jaundice >14 days, pale stools; Kasai before 60 days; many need eventual liver transplant.
Wilms = smooth mass, does not cross midline, age 3-4; nephrectomy ± chemotherapy; excellent prognosis; bilateral in 5%.
Mastoiditis = post-auricular swelling, pinna protrusion; CT temporal bone; IV antibiotics + mastoidectomy if abscess; intracranial complications are life-threatening.
Paediatric appendicitis = ultrasound (not CT); laparoscopic appendicectomy; younger children perforate faster; appendix mass may be managed conservatively initially.
Adenoidectomy for nasal obstruction, OSA, recurrent OME; often combined with tonsillectomy; caution in cleft palate; adenoids involute by age 7-8.
Paediatric umbilical hernia = usually closes by age 3-5; surgery if persists beyond 4-5 years or complications; no strapping.
Nasal fracture = reassess at 5-7 days; MUA within 2-3 weeks; exclude septal haematoma; late correction = septorhinoplasty.
Intussusception = colicky pain, redcurrant jelly stool, target sign on USS; air enema reduction first-line; surgery if failed or peritonitis.
Hirschsprung = delayed meconium, explosive decompression on PR; suction biopsy confirms absent ganglia; pull-through surgery is definitive.
Meconium ileus = CF association; Gastrografin enema for diagnosis and treatment; surgery if failed or complicated; confirm CF with sweat test.
CDH = stabilise before surgery; avoid bag-mask; NG decompression; pulmonary hypoplasia determines prognosis; Bochdalek most common.
Supracondylar = brachial artery and AIN at risk; urgent reduction and K-wires; Volkmann contracture if compartment syndrome missed.
Pulled elbow = traction injury, pronated arm, age 1-4; hyperpronation to reduce; no X-ray if classic history; recurrence common.
DDH = Barlow/Ortolani screening; Pavlik harness <6 months; USS confirms; late presentation needs open reduction; risk = breech, female, family history.
Clubfoot = CAVE deformity; Ponseti casting + tenotomy + brace; brace compliance prevents relapse; surgery reserved for resistant cases.
Quinsy = unilateral sore throat, trismus, hot potato voice; needle aspiration or I&D; IV antibiotics; consider tonsillectomy for recurrence.
Otitis externa = tragal pain, topical drops, aural toilet; pope wick if swollen; malignant OE in diabetics = Pseudomonas, needs IV antibiotics.
Submandibular stones most common; meal-related swelling; transoral removal if palpable; sialoendoscopy or excision; protect nerves at surgery.
Thyroglossal cyst = midline, moves on tongue protrusion; Sistrunk = cyst + tract + central hyoid; confirm normal thyroid preoperatively.