What is the recommended starting dose of propofol (sedative) for an adult patient in Intensive Care Unit (ICU) care requiring sedation?

Propofol Dosing for ICU Sedation

Start propofol at 5 μg/kg/min (0.3 mg/kg/hr) without a loading bolus in most ICU patients, and titrate within the maintenance range of 5-50 μg/kg/min to achieve light sedation. 1, 2

Initial Dosing Strategy

• Avoid loading boluses in hemodynamically unstable patients due to significant hypotension risk 1
• If the patient is hemodynamically stable and a loading dose is deemed necessary, administer 5 μg/kg/min over 5 minutes only 1, 2
• Begin the maintenance infusion immediately at 5 μg/kg/min and titrate upward based on sedation response 1, 2

Maintenance Dosing Range

• Most adult ICU patients require 5-50 μg/kg/min (0.3-3 mg/kg/hr) for adequate sedation 1
• Target light sedation levels (patient arousable and able to follow simple commands) rather than deep sedation to minimize complications including delirium and prolonged mechanical ventilation 3, 1
• Use validated sedation scales (RASS or SAS) to titrate to target sedation depth 3

Time-Based Dosing Algorithm

After 48 hours of continuous propofol infusion, strongly consider transitioning to an alternative sedative to minimize propofol infusion syndrome (PRIS) risk:

• Switch to dexmedetomidine: Load with 1 μg/kg over 10 minutes, then maintain at 0.2-0.7 μg/kg/hr (monitor for bradycardia and hypotension) 2
• Alternative: Switch to midazolam: Load with 0.01-0.05 mg/kg, then maintain at 0.02-0.1 mg/kg/hr 2
• If continuing propofol beyond 48 hours is necessary, maintain rates at 5-50 μg/kg/min and reassess daily 2

Critical Safety Monitoring

Never exceed 70 μg/kg/min as this dramatically increases PRIS risk, which carries up to 33% mortality 1, 2

Monitor for Propofol Infusion Syndrome (PRIS):

• Unexplained metabolic acidosis (earliest warning sign)
• Hypertriglyceridemia
• Hypotension requiring escalating vasopressor support
• Cardiac arrhythmias
• Acute kidney injury with hyperkalemia
• Rhabdomyolysis 1, 2

Daily Laboratory Monitoring (especially if >48 hours):

• Serum triglycerides
• Arterial blood gases
• Renal function tests
• Liver function tests 2

Immediately discontinue propofol if PRIS is suspected and provide supportive care 2

Common Adverse Effects to Anticipate

• Dose-dependent hypotension from systemic vasodilation—the most common complication 1, 4
• Respiratory depression requiring mechanical ventilation 1
• Pain on injection through peripheral veins 1
• Hypertriglyceridemia with prolonged infusions 1
• 5-7% of patients may experience transient desaturation below 90% 1

Special Considerations

Elderly Patients:

• Use lower initial doses due to decreased volume of distribution and higher peak plasma concentrations, which predispose to hypotension, apnea, and oxygen desaturation 4

Nutritional Considerations:

• Account for propofol's caloric contribution of 1.1 kcal/mL from the lipid emulsion when calculating nutritional requirements 1
• Patients receiving large doses may need reduced energy and fat supplementation to prevent overfeeding 1

Contraindications:

• Egg or soybean allergies (propofol is dissolved in 10% lipid emulsion) 1

Recovery Characteristics

• Propofol has rapid onset (1-2 minutes) and short elimination half-life (3-12 hours), allowing excellent control of sedation depth 1
• After short-term use (<24 hours), expect awakening within 10-15 minutes of discontinuation 4, 5
• After prolonged infusions (>48 hours), recovery may take longer due to tissue accumulation, but maintaining the lowest effective dose enables rapid awakening even after extended use 4, 5
• Daily sedation interruption protocols facilitate neurological assessments and reduce total sedative exposure 3, 1

Key Clinical Pitfalls to Avoid

• Administering loading doses to hemodynamically unstable patients 1
• Using doses >70 μg/kg/min or failing to monitor for PRIS with prolonged infusions 1, 2
• Missing early signs of PRIS, particularly unexplained metabolic acidosis 1, 2
• Continuing propofol beyond 48 hours without considering alternative sedatives 2
• Failing to account for caloric contribution when calculating nutrition 1
• Not reducing infusion rates after extended use, leading to excessively high drug concentrations 4