Propofol Dosing in the ICU
For ICU sedation, propofol should be initiated with a continuous infusion at 5 mcg/kg/min (0.3 mg/kg/h) and titrated by increments of 5-10 mcg/kg/min every 5 minutes to achieve desired sedation level, with maintenance dosing typically ranging from 5-50 mcg/kg/min (0.3-3 mg/kg/h). 1
Initial Dosing and Titration
- Avoid bolus loading doses in hemodynamically unstable patients due to risk of hypotension; if needed, use 5 μg/kg/min over 5 minutes only in patients where hypotension is unlikely to occur 2
- Start with 5 mcg/kg/min (0.3 mg/kg/h) continuous infusion and titrate in increments of 5-10 mcg/kg/min (0.3-0.6 mg/kg/h) 1
- Allow a minimum of 5 minutes between dose adjustments to assess peak drug effect 1
- Target light sedation levels when possible (patient arousable and able to follow simple commands) rather than deep sedation to minimize complications 2
Maintenance Dosing
- Most adult ICU patients require maintenance rates of 5-50 mcg/kg/min (0.3-3 mg/kg/h) 1, 2
- Do not exceed 4 mg/kg/hour (66.7 mcg/kg/min) unless benefits outweigh risks of propofol infusion syndrome 1
- Reduce propofol dosage in patients who have received large doses of opioids 1
- Daily evaluation of sedation level is necessary to determine the minimum effective dose 1
Special Considerations and Dose Adjustments
- Elderly, debilitated, and ASA-PS III or IV patients may have exaggerated hemodynamic and respiratory responses to propofol; use lower doses 1
- Patients with compromised myocardial function, intravascular volume depletion, or abnormally low vascular tone (e.g., sepsis) are more susceptible to hypotension; use caution with dosing 1
- Consider propofol's caloric contribution (1.1 kcal/ml from lipid emulsion) when calculating nutritional requirements; patients receiving large doses may need lower energy and fat requirements to prevent overfeeding 2
Monitoring and Safety
- Monitor for propofol infusion syndrome (PRIS), especially with doses >70 μg/kg/min or prolonged infusions 3
- Signs of PRIS include metabolic acidosis, hypertriglyceridemia, hypotension requiring increasing vasopressor support, arrhythmias, acute kidney injury, hyperkalemia, and rhabdomyolysis 2, 3
- Check serum triglycerides, arterial blood gases, and renal/liver function tests regularly during prolonged infusions 3
- The incidence of PRIS is approximately 1% with propofol infusions, but mortality is high (up to 33%) 2
Advantages of Propofol for ICU Sedation
- Rapid onset (1-2 minutes) and short elimination half-life (3-12 hours) allow for better control of sedation level 2
- Facilitates daily sedation interruption protocols and neurological assessments 2
- Shorter emergence time compared to benzodiazepines, particularly after short-term use 4
- Patients sedated with propofol awaken more rapidly (23±16 mins) compared to midazolam (137±185 mins) 4
Common Adverse Effects
- Pain on injection through peripheral veins 2
- Dose-dependent hypotension due to systemic vasodilation 2
- Respiratory depression (requires mechanical ventilation) 2
- Hypertriglyceridemia 2
- Risk of allergic reactions in patients with egg or soybean allergies (propofol is dissolved in 10% lipid emulsion) 2
Clinical Pitfalls to Avoid
- Administering loading doses in hemodynamically unstable patients 2, 1
- Using high doses (>70 μg/kg/min) or prolonged infusions without monitoring for PRIS 3
- Failing to recognize early signs of PRIS such as unexplained metabolic acidosis 3
- Not accounting for propofol's caloric contribution when calculating nutritional requirements 2
- Rapid discontinuation after prolonged deep sedation, which can lead to withdrawal symptoms 5
Following these evidence-based dosing recommendations will help optimize sedation while minimizing the risk of adverse effects in critically ill patients requiring ICU sedation.