What is the propofol (propofol) infusion rate in drops per minute for a 70kg male?

Propofol Infusion Rate Calculation for a 70kg Male

For ICU sedation in a 70kg male, propofol maintenance infusion typically requires 5-50 mcg/kg/min (0.3-3 mg/kg/h), which translates to approximately 21-210 mg/hour, but drops per minute cannot be calculated without knowing the specific IV tubing drop factor and propofol concentration being used. 1

Critical Information Needed for Drop Calculation

To convert propofol infusion rates to drops per minute, you must know:

• Propofol concentration (typically 10 mg/mL in standard formulations) 2
• IV tubing drop factor (microdrip = 60 drops/mL; macrodrip = 10-20 drops/mL depending on manufacturer)

Standard Dosing Ranges for Different Clinical Contexts

ICU Sedation (Most Common Scenario)

• Maintenance rate: 5-50 mcg/kg/min for most adult ICU patients 1
• For 70kg patient: 350-3,500 mcg/min = 0.35-3.5 mg/min = 21-210 mg/hour 1
• Avoid loading boluses in hemodynamically unstable patients; if needed, use 5 mcg/kg/min over 5 minutes only when hypotension unlikely 1
• High-risk threshold: Doses >70 mcg/kg/min (>4,900 mcg/min or 294 mg/hour in 70kg patient) increase propofol infusion syndrome risk 1, 3

General Anesthesia Maintenance

• Initial maintenance: 100-200 mcg/kg/min (7-14 mg/min or 420-840 mg/hour for 70kg) for first 10-15 minutes 2
• Subsequent maintenance: Decrease 30-50% after first half-hour; target 50-100 mcg/kg/min (3.5-7 mg/min or 210-420 mg/hour for 70kg) 2

Monitored Anesthesia Care (MAC) Sedation

• Typical range: 25-75 mcg/kg/min (1.75-5.25 mg/min or 105-315 mg/hour for 70kg) 2
• Initiation: 100-150 mcg/kg/min for 3-5 minutes, then titrate down 2

Example Calculation (Using Standard Parameters)

Assuming:

• 70kg patient requiring ICU sedation at 50 mcg/kg/min (mid-range maintenance)
• Propofol 10 mg/mL concentration
• Microdrip tubing (60 drops/mL)

Calculation:

1. 50 mcg/kg/min × 70kg = 3,500 mcg/min = 3.5 mg/min
2. 3.5 mg/min ÷ 10 mg/mL = 0.35 mL/min
3. 0.35 mL/min × 60 drops/mL = 21 drops/minute

Clinical Pitfalls and Safety Considerations

Propofol Infusion Syndrome (PRIS) Monitoring

• Monitor for PRIS with doses >70 mcg/kg/min (>4,900 mcg/min for 70kg) or prolonged infusions 1, 3
• PRIS signs: Metabolic acidosis, hypertriglyceridemia, hypotension requiring increasing vasopressors, arrhythmias, acute kidney injury, hyperkalemia, rhabdomyolysis 1, 3
• PRIS incidence: ~1% but mortality up to 33% 1, 3
• Daily monitoring: Serum triglycerides, arterial blood gases, renal and liver function tests 3

Hemodynamic Considerations

• Dose-dependent hypotension due to systemic vasodilation 1
• Elderly/debilitated patients: Reduce dose to ~80% of usual adult dosage; avoid rapid boluses 2
• Respiratory depression: Requires mechanical ventilation or close monitoring 1

Nutritional Impact

• Caloric contribution: 1.1 kcal/mL from lipid emulsion 1
• For 70kg at 50 mcg/kg/min: 0.35 mL/min × 60 min × 24 hours = 504 mL/day = 554 kcal/day
• Adjust nutritional requirements to prevent overfeeding with large propofol doses 1

Advantages Over Benzodiazepines

• Rapid onset (1-2 minutes) and short elimination half-life (3-12 hours) 1
• Improved outcomes versus benzodiazepines: shorter mechanical ventilation duration, less delirium, reduced length of stay 4
• Shorter recovery time compared to midazolam 1

Practical Recommendation

Without knowing your specific IV tubing drop factor and propofol concentration, use an infusion pump calibrated in mL/hour rather than counting drops. For a 70kg male requiring standard ICU sedation at 50 mcg/kg/min with 10 mg/mL propofol, set the pump to 21 mL/hour (0.35 mL/min × 60 = 21 mL/hour). 1, 2