What is the recommended dosage and use of Propofol (propofol) for inducing and maintaining anesthesia or sedation?

Propofol Dosage and Administration for Anesthesia and Sedation

For adult patients requiring anesthesia or sedation, propofol should be administered at an induction dose of 2-2.5 mg/kg for ASA I-II patients under 55 years, followed by maintenance infusion of 50-100 mcg/kg/min to optimize recovery times. 1

Mechanism and Pharmacokinetics

• Propofol (2,6-diisopropylphenol) is a hypnotic agent with minimal analgesic effect that produces sedation and amnesia at subhypnotic doses 2
• Its hypnotic effect results from potentiation of GABA through reduction in GABA-receptor dissociation rate 2
• Highly lipid soluble with rapid onset of action (30-45 seconds, equivalent to one arm-brain circulation) 2, 3
• Duration of effect is 4-8 minutes after a single dose 2, 3
• Rapidly metabolized in the liver by conjugation to glucuronide and sulfate, producing water-soluble compounds excreted by the kidneys 2, 3

Dosing for Induction of General Anesthesia

Adult Patients

• ASA I-II patients under 55 years: 2-2.5 mg/kg when unpremedicated or premedicated with benzodiazepines/opioids 1
• Elderly, debilitated, or ASA III-IV patients: 1-1.5 mg/kg (approximately 20 mg every 10 seconds) 1
• Titrate against patient response (approximately 40 mg every 10 seconds) until clinical signs show onset of anesthesia 1
• Avoid rapid bolus in elderly or high-risk patients to prevent cardiorespiratory depression 1

Pediatric Patients

• Ages 3-16 years (ASA I-II): 2.5-3.5 mg/kg 1
• Lower doses recommended for ASA III-IV pediatric patients 1
• Younger pediatric patients may require higher induction doses than older children 1

Special Populations

• Neurosurgical patients: Slower induction using boluses of 20 mg every 10 seconds; reduced requirements (1-2 mg/kg) 1
• Cardiac patients: Slow rate of approximately 20 mg every 10 seconds until induction (0.5-1.5 mg/kg) 1

Maintenance of General Anesthesia

Adult Patients

• Continuous infusion: 100-200 mcg/kg/min initially, then decrease by 30-50% during first half-hour 1
• Maintenance rate: 50-100 mcg/kg/min to optimize recovery times 1
• Intermittent bolus: Increments of 25-50 mg when vital signs indicate response to surgical stimulation 1

Pediatric Patients

• Initial rate: 200-300 mcg/kg/min immediately following induction 1
• After first half-hour: 125-150 mcg/kg/min typically needed 1
• Younger pediatric patients may require higher maintenance rates 1

Monitored Anesthesia Care (MAC) Sedation

• Typical rate range: 25-75 mcg/kg/min, individualized and titrated to clinical response 1
• Initiation by infusion: 100-150 mcg/kg/min (6-9 mg/kg/h) for 3-5 minutes, then titrate 1
• In elderly, debilitated, or ASA III-IV patients, avoid rapid bolus administration 1

Nurse-Administered Propofol Sedation (NAPS)

• Initial bolus: 10-60 mg 2
• Additional boluses: 10-20 mg with minimum of 20-30 seconds between doses 2
• Average doses for endoscopy:
  • EGD: 72-245 mg
  • Colonoscopy: 94-287 mg 2
• Continuous monitoring of heart rate, blood pressure, and pulse oximetry is essential 2

Adverse Effects and Precautions

• Cardiovascular effects include decreased cardiac output, systemic vascular resistance, and arterial pressure 2, 3, 4
• Respiratory depression is dose-dependent; may require dose reduction or interruption 2
• Pain on injection reported in up to 30% of patients 2, 3
• Current formulation contains soybean oil, glycerol, and egg phosphatide; avoid in patients with allergies to egg, soy, or sulfites 2, 3
• Co-administration with other CNS depressants (opioids, benzodiazepines) potentiates sedative effects 2, 1
• Propofol infusion syndrome may occur with prolonged administration (>48 hours) at high doses (>4 mg/kg/h), characterized by metabolic acidosis, rhabdomyolysis, arrhythmias, and organ failure 5

Clinical Pearls and Pitfalls

• Always titrate propofol dose against individual patient needs and responses due to considerable variability in requirements 6
• Reduce induction dose by 20-80% when used with sedatives or analgesics as part of balanced technique 6
• Propofol lacks significant analgesic effects; consider supplementation with opioids or local anesthetics for painful procedures 6
• Use with extreme caution in patients with pulmonary hypertension due to potential for hemodynamic instability 4
• For cardiac patients, maintenance infusion rates should not be less than 100 mcg/kg/min when used as primary agent, and should be supplemented with opioids 1
• Recovery from propofol is typically rapid and clear-headed with minimal hangover effect, making it suitable for outpatient procedures 7, 8