Key Facts

Procedural sedation enables uncomfortable or painful procedures to be performed safely and humanely outside the operating theatre. It requires trained staff, appropriate monitoring, and immediate access to resuscitation equipment.

Epidemiology

Procedural sedation is performed in emergency departments, endoscopy units, radiology departments, dental surgeries, and outpatient settings. The vast majority of procedures are performed safely, but over-sedation and respiratory compromise remain significant risks.

Aetiology

Procedures commonly requiring sedation include: fracture reduction, joint reduction, cardioversion, endoscopy, bronchoscopy, dental extractions, abscess drainage, lumbar puncture, and imaging (MRI/CT) in children or anxious adults.

Pathophysiology

Procedural sedation aims to achieve a state where the patient is comfortable and cooperative but retains protective airway reflexes and the ability to respond to verbal commands. The boundary between moderate and deep sedation is narrow and may be inadvertently crossed, particularly in elderly patients, those with comorbidities, or with rapid drug administration.

Pre-Sedation Assessment

• ASA classification: Generally ASA I-III suitable; ASA IV requires anaesthetist-led sedation
• Airway assessment: Mallampati, BMI, OSA risk
• Fasting status: Ideally fasted, but risk-benefit in emergency
• Medication history: Opioids, benzodiazepines (tolerance), respiratory depressants
• Consent: Written, informed consent for sedation AND procedure

During Sedation

• Patient responsive to verbal commands (moderate sedation)
• Spontaneous ventilation maintained
• Cardiovascular function usually maintained
• Analgesia and anxiolysis adequate for procedure

Post-Sedation Recovery

• Monitoring until return to baseline consciousness
• Must meet discharge criteria before leaving
• Written discharge instructions including activity restrictions (no driving for 24h)

Red Flags

• Loss of verbal contact — patient has entered deep sedation
• SpO2 <92% or RR <8 — airway management required
• Oxygen desaturation not detected by pulse oximetry — capnography provides earlier warning
• Paradoxical agitation — more common with midazolam in elderly/children

Bedside

• Pre-sedation checklist: ASA grade, fasting, allergies, consent, equipment check
• Continuous monitoring: SpO2, NIBP every 5 min, capnography (recommended), ECG if cardiac risk
• Recovery assessment: Aldrete score or equivalent discharge criteria tool

Bloods

• Generally not required unless guided by underlying medical conditions

Imaging

• Not applicable to sedation itself

Special Tests

• Not routinely required; guided by procedure and patient factors

Non-pharmacological

• Environment: Appropriate area with monitoring, suction, oxygen, resuscitation drugs and equipment
• Staffing: Trained sedationist + dedicated observer (not performing the procedure)
• Pre-procedure: Establish IV access, attach monitoring, position patient, confirm consent
• Non-pharmacological adjuncts: Distraction, music, child life specialist for paediatric patients

Pharmacological

Adult procedural sedation:

• Midazolam 1-2mg IV titrated (wait 2 min between doses) ± fentanyl 25-50mcg IV
• Propofol 0.5-1mg/kg IV then 10-20mg boluses titrated (for deeper sedation)
• Entonox (50:50 N2O/O2): Self-administered for mild procedures

Paediatric procedural sedation:

• Ketamine 1-2mg/kg IV (onset 1 min) or 4-5mg/kg IM (onset 5 min) — with atropine 20mcg/kg to reduce secretions
• Midazolam: 0.5mg/kg PO (max 20mg) for anxiolysis/imaging sedation
• Chloral hydrate: 25-50mg/kg PO for infants (CT/MRI sedation — declining use)

Reversal agents:

• Flumazenil: 200mcg IV over 15s (benzodiazepine reversal); repeat at 1-min intervals; max 1mg. Caution: short half-life, risk of re-sedation, seizure risk in chronic benzo users.
• Naloxone: 400mcg IV (opioid reversal); repeat every 2-3 min

Surgical/Interventional

• Not applicable

Referral Criteria

• ASA IV patients — anaesthetist-led sedation
• Known difficult airway — anaesthetist involvement
• Deep sedation required — anaesthetist or trained sedationist with airway skills
• Failure of moderate sedation to achieve adequate conditions — consider GA

• Procedural sedation is very safe when guidelines are followed: serious adverse event rate <1%
• Ketamine in children: Excellent safety profile; vomiting in ~10-20%, emergence phenomena rare in children (<5%)
• Midazolam in elderly: Requires dose reduction (0.5-1mg initial dose); prolonged action; higher risk of complications
• Same-day discharge: Majority of patients discharged within 1-2 hours of sedation

Discharge Criteria After Procedural Sedation

Paediatric Sedation Drug Doses