Propofol Infusion Dosing for ICU Sedation
For adult ICU sedation, propofol should be administered at maintenance infusion rates of 5-50 mcg/kg/min (0.3-3 mg/kg/h), with most patients adequately sedated within this range. 1, 2, 3
Initial Dosing Strategy
Avoid bolus loading doses in hemodynamically unstable patients due to significant hypotension risk; if a loading dose is necessary in stable patients, use 5 mcg/kg/min over 5 minutes only 2
Start with maintenance infusion rates of 5-50 mcg/kg/min immediately following any loading dose to maintain continuous sedation 1, 2
During the initial 10-15 minutes after induction, higher infusion rates of 100-200 mcg/kg/min may be required, then decrease by 30-50% during the first half-hour of maintenance 3
Maintenance Dosing Parameters
Target maintenance range: 25-75 mcg/kg/min for most adult ICU patients, with the majority requiring approximately 27 mcg/kg/min on average 3
Infusion rates should be titrated downward over time to 25-50 mcg/kg/min and adjusted based on clinical response using validated sedation scales (RASS or SAS) 1, 2
Elderly patients (>55 years) require lower doses, averaging approximately 20 mcg/kg/min compared to 38 mcg/kg/min in younger patients, due to decreased volume of distribution and higher peak plasma concentrations 3
Reduce dosage to approximately 80% of usual adult dosing in elderly, debilitated, or ASA-PS III/IV patients 3
Critical Safety Thresholds
Never exceed 70 mcg/kg/min for prolonged periods (>48 hours) due to risk of propofol infusion syndrome (PRIS) 2, 4, 5
PRIS presents with metabolic acidosis, rhabdomyolysis, cardiac arrhythmias, acute kidney injury, hyperkalemia, and has mortality rates up to 33% 2, 4, 6
The incidence of PRIS is approximately 1%, but can occur even at lower doses (as low as 1.9-2.6 mg/kg/h or 32-43 mcg/kg/min) 2, 5
Duration-Based Dosing Adjustments
For sedation <48 hours: Maintain propofol at 5-50 mcg/kg/min with daily reassessment 4
For sedation >48 hours: Strongly consider transitioning to dexmedetomidine (0.2-0.7 mcg/kg/hr) or midazolam-based sedation to avoid PRIS risk 4
Alternative strategy: Use an analgesic-first approach with low-dose fentanyl infusion plus minimal sedative after 48 hours 4
Monitoring Requirements
Monitor daily for PRIS indicators: serum triglycerides, arterial blood gases, renal and liver function tests, creatine kinase 4
Use validated sedation scales to titrate to light sedation targets (patient arousable, follows simple commands) rather than deep sedation 1, 2
Implement daily sedation interruption protocols to assess neurologic status and reduce total sedative exposure 1
Account for propofol's caloric contribution of 1.1 kcal/mL from lipid emulsion when calculating nutritional requirements 2
Common Pitfalls to Avoid
Rapid bolus administration in unstable patients causes profound hypotension, apnea, and oxygen desaturation; always infuse slowly over 3-5 minutes 3
Failing to recognize early PRIS signs such as unexplained metabolic acidosis or increasing vasopressor requirements; discontinue propofol immediately if suspected 2, 4
Using high doses (>70 mcg/kg/min) beyond 48 hours dramatically increases PRIS risk 4, 5
Not reducing doses in elderly patients leads to excessive cardiorespiratory depression due to higher peak plasma concentrations 3
Comparative Context
Propofol provides shorter recovery times (averaging 15.5 minutes) compared to benzodiazepines like midazolam, facilitating neurological assessments 1, 7
However, propofol causes more cardiovascular depression (68% of patients experience >20% decrease in systolic blood pressure) compared to midazolam (31%) 8
Propofol has minimal amnesia (only one-third of patients) compared to complete amnesia with midazolam 8