MSRA Question Bank

DKA is a medical emergency requiring immediate IV fluid resuscitation followed by fixed-rate insulin infusion per JBDS guidelines. Initial management is 0.9% sodium chloride 1L in the first hour (500mL in 15 minutes if systolic BP <90mmHg), followed by fixed-rate IV insulin at 0.1 units/kg/hr. Potassium replacement is guided by serum levels: if K+ is 3.5-5.5mmol/L add 40mmol/L KCl to each bag; if above 5.5mmol/L defer replacement but recheck in 2 hours.

Subcutaneous insulin is inadequate in DKA due to peripheral vasoconstriction and poor absorption. IV insulin boluses are no longer recommended. The goal is ketone clearance (blood ketones falling by ≥0.5mmol/L/hr), not just glucose reduction. Once glucose falls below 14mmol/L, add 10% dextrose alongside continued insulin to prevent hypoglycaemia while clearing ketosis. IV bicarbonate is not routinely recommended and only considered by senior clinicians if pH <6.9.

Precipitating factors must be identified - infection, omission of insulin, and new diagnosis are the commonest triggers. Long-acting insulin should be continued throughout admission.

Remember: In DKA, treat the ketosis not just the glucose - fixed-rate insulin continues until blood ketones are below 0.6mmol/L.

HHS is characterised by severe hyperglycaemia (>30mmol/L), hyperosmolality (>320mOsm/kg), and hypovolaemia without significant ketoacidosis, requiring cautious fluid resuscitation as the mainstay of treatment. Per JBDS guidelines, IV 0.9% saline is the initial fluid of choice. The aim is to normalise osmolality gradually over 24-48 hours, as rapid correction risks cerebral oedema and central pontine myelinolysis.

Insulin should not be started initially unless blood ketones are above 1.0mmol/L or glucose fails to fall with fluids alone. Fluid replacement alone typically reduces glucose by 3-5mmol/L/hr. If insulin is needed, use a low-dose fixed-rate infusion (0.05 units/kg/hr) to avoid precipitous falls in osmolality. Target glucose fall should not exceed 5mmol/L/hr.

Hypotonic saline (0.45%) is only considered if osmolality is not falling despite adequate positive fluid balance. VTE prophylaxis with LMWH is essential as HHS carries a very high thrombotic risk. Precipitating causes include infection, myocardial infarction, stroke, and medication changes.

Remember: In HHS, fluids are the primary treatment - insulin is deferred initially, and osmolality must fall gradually over 24-48 hours to prevent neurological complications.

Type 1 diabetes requires lifelong insulin therapy from diagnosis - this patient has classic features including young age, lean habitus, rapid weight loss, positive anti-GAD antibodies, and low C-peptide confirming autoimmune beta-cell destruction. Per NICE NG17, a basal-bolus insulin regimen (once-daily long-acting insulin plus rapid-acting insulin with meals) is the recommended first-line regimen. Twice-daily mixed insulin is an alternative if basal-bolus is not acceptable.

Anti-GAD, anti-IA2, and anti-ZnT8 antibodies confirm autoimmune aetiology. C-peptide reflects residual beta-cell function and is characteristically low or undetectable. HbA1c of 98mmol/mol indicates prolonged hyperglycaemia preceding diagnosis. This patient has ketonaemia but pH >7.3 so does not meet full DKA criteria, though close monitoring is essential.

All patients should be referred to specialist diabetes services within 24 hours of diagnosis for structured education (DAFNE programme), carbohydrate counting training, and blood glucose monitoring support. Screening for coexisting autoimmune conditions (thyroid disease, coeliac disease) should be performed at diagnosis.

Remember: Type 1 diabetes requires insulin from day one - oral hypoglycaemics are never appropriate, and anti-GAD antibodies with low C-peptide confirm the diagnosis.