What is the recommended propofol infusion formula for a 90 kg male with potential cardiovascular disease?

Propofol Infusion Formula for a 90 kg Male with Potential Cardiovascular Disease

For a 90 kg male with potential cardiovascular disease, avoid bolus loading doses and start with a maintenance infusion of 5 mcg/kg/min (27 mg/hour or 0.45 mg/min), which can be titrated up to 50 mcg/kg/min (270 mg/hour or 4.5 mg/min) based on sedation response, while closely monitoring for hypotension. 1

Initial Dosing Strategy

Avoid Loading Doses in Cardiovascular Disease

• Do not administer bolus loading doses in patients with potential cardiovascular disease due to significant hypotension risk 1
• Propofol causes dose-dependent hypotension through systemic vasodilation, which is particularly problematic in hemodynamically unstable patients 1
• If a loading dose is absolutely necessary and the patient is hemodynamically stable, use only 5 mcg/kg/min over 5 minutes (approximately 27 mg total for 90 kg patient) 1

Starting Maintenance Infusion

• Begin with 5 mcg/kg/min (0.3 mg/kg/hour) = 27 mg/hour for this 90 kg patient 1
• This translates to 0.45 mg/min or 27 mL/hour if using 1% propofol solution (10 mg/mL) 2, 3
• Target light sedation initially (patient arousable and able to follow simple commands) rather than deep sedation 1

Titration Protocol

Dose Escalation

• Most adult ICU patients require maintenance rates of 5-50 mcg/kg/min (0.3-3 mg/kg/hour) 1
• For this 90 kg patient, the range is 27-270 mg/hour (0.45-4.5 mg/min) 1
• Titrate upward in increments of 5-10 mcg/kg/min every 5-10 minutes based on sedation level 1

Practical Infusion Rates for 90 kg Patient

• Low dose: 27 mg/hour (5 mcg/kg/min) 1
• Moderate dose: 135 mg/hour (25 mcg/kg/min) 1
• High dose: 270 mg/hour (50 mcg/kg/min) 1

Critical Safety Monitoring

Propofol Infusion Syndrome (PRIS) Warning

• Never exceed 70 mcg/kg/min (378 mg/hour for 90 kg patient) due to risk of PRIS 1
• PRIS has approximately 1% incidence but carries up to 33% mortality 1
• Monitor for metabolic acidosis, hypertriglyceridemia, hypotension requiring increasing vasopressor support, arrhythmias, acute kidney injury, hyperkalemia, and rhabdomyolysis 1

Cardiovascular Monitoring

• Propofol decreases systolic and diastolic blood pressure by approximately 20-30% during induction 2
• Expect minimal change in heart rate despite blood pressure reduction 2
• 5-7% of patients may experience transient desaturation below 90% 1
• Continuous blood pressure monitoring is essential, especially in patients with cardiovascular disease 1

Special Considerations for This Patient

Nutritional Accounting

• Propofol provides 1.1 kcal/mL from lipid emulsion 1
• At 270 mg/hour (27 mL/hour of 1% solution), this delivers approximately 30 kcal/hour 1
• Adjust nutritional requirements to prevent overfeeding with prolonged infusions 1

Contraindications to Verify

• Confirm no egg or soybean allergies (propofol is dissolved in 10% lipid emulsion containing egg phosphatide and soybean oil) 1, 3
• Assess for defective lipid metabolism, pathological hyperlipidemia, lipoid nephrosis, or acute pancreatitis 4

Advantages for Short-Term Use

• Rapid onset of 1-2 minutes with short elimination half-life of 3-12 hours 1
• Recovery typically occurs within 15.5 minutes after stopping infusion 5
• Shorter recovery time compared to benzodiazepines like midazolam 1
• Facilitates daily sedation interruption and neurological assessments 1

Common Pitfalls to Avoid

• Never give loading doses to hemodynamically unstable patients 1
• Never use doses >70 mcg/kg/min or prolonged infusions without monitoring for PRIS 1
• Never fail to recognize early signs of PRIS such as unexplained metabolic acidosis 1
• Never forget to account for propofol's caloric contribution in nutritional calculations 1
• Expect pain on injection through peripheral veins, though this rarely causes phlebitis 1, 3

Calculation Formula for Infusion Rate

Infusion rate (mL/hour) = [weight (kg) × dose (mcg/kg/min) × 60 (min/hour)] ÷ concentration (mcg/mL) 6

For this 90 kg patient starting at 5 mcg/kg/min using 1% propofol (10,000 mcg/mL):

• (90 kg × 5 mcg/kg/min × 60) ÷ 10,000 = 27 mL/hour 6