Procedural Sedation Prescribing

Procedural sedation produces a depressed level of consciousness that allows an uncomfortable procedure while the patient keeps protective airway reflexes and breathes spontaneously. It can progress to general anaesthesia, so only clinicians able to rescue the airway should give it.

Preparation. Assess airway, anaesthetic risk class, fasting history, allergies and the planned procedure. Prepare monitoring, suction, oxygen, bag-mask, airway adjuncts and reversal agents. Use one clinician to monitor and one to perform. Fasting is not always possible in emergencies.

Monitoring. Continuous pulse oximetry, ECG, blood pressure every 3 to 5 minutes, and capnography.

By procedure.

• Painful, short procedures (reduction of fracture or dislocation, abscess drainage): ketamine, or propofol with an opioid.

• Cardioversion: etomidate or propofol.

• Minor procedures: nitrous oxide in oxygen 50 percent, or midazolam with a low-dose opioid.

Avoid. Ketamine in psychosis, and in uncontrolled hypertension or raised intraocular pressure unless benefits outweigh risk. Propofol in unstable patients. Combined benzodiazepine and opioid in older or frail patients.

Special groups.

• Children: ketamine is the usual agent, with laryngospasm risk in infants under 12 months and with respiratory infection.

• Pregnancy: use the lowest doses and ensure left lateral tilt.

• Older adults: halve initial doses.

• East Africa: ketamine is often the sole available agent and is suitable with oxygen and monitoring.

• Ketamine: 1 to 2 mg/kg intravenously, with a repeat of 0.5 to 1 mg/kg after 10 to 15 minutes. Intramuscular 4 to 5 mg/kg.

• Propofol: 0.5 to 1 mg/kg intravenously, then 0.25 to 0.5 mg/kg every 1 to 3 minutes as needed.

• Etomidate: 0.1 to 0.15 mg/kg intravenously.

• Midazolam: 0.02 to 0.05 mg/kg intravenously, titrated slowly (1 to 2 mg, repeated every 3 to 5 minutes, usual maximum 5 mg in adults).

• Fentanyl: 0.5 to 1 microgram/kg intravenously, titrated in 25 to 50 microgram steps.

• Flumazenil: 0.2 mg intravenously over 15 seconds, then 0.1 to 0.2 mg every minute to a maximum of 1 mg. Naloxone: 0.04 to 0.4 mg in small steps.

Recovery. Observe until alert and at baseline, usually 30 to 60 minutes after the last dose, and 1 to 2 hours after benzodiazepine or opioid use. Give written instructions and an escort.

Stop rules. Stop and support the airway for loss of airway reflexes, apnoea, or oxygen saturation under 90 percent. Use a jaw thrust, bag-mask ventilation and oxygen.

Referral and escalation. Call anaesthetic help for failed ventilation, laryngospasm unresponsive to positive pressure (give suxamethonium 0.5 to 1 mg/kg intravenously, or intramuscular 4 mg/kg if no access), or a patient who needs deeper sedation than planned.

Common errors. Giving drugs as large boluses, stacking benzodiazepine and opioid, working without capnography, and discharging too early after reversal agents wear off.