In an adult patient requiring moderate sedation, what are the recommended propofol bolus (milligrams per kilogram) and maintenance infusion (micrograms per kilogram per minute) doses, and what fentanyl dosing (micrograms per kilogram) should be used, especially in elderly patients or those with cardiac or respiratory disease?

Propofol and Fentanyl Dosing for Moderate Sedation in Adults

Propofol Bolus Dosing

For moderate sedation in adults, administer an initial propofol bolus of 20-40 mg, reduced to 10-15 mg in elderly patients or when combined with opioids/benzodiazepines. 1, 2

• When propofol is combined with fentanyl or other sedatives, use lower initial doses of 10-20 mg to minimize respiratory depression 1, 2
• Administer subsequent boluses of 10-20 mg every 20-30 seconds as needed to maintain desired sedation level 2
• Allow adequate time between doses (20-30 seconds minimum) to assess peak effect before administering additional drug 3

Special Population Adjustments

• Elderly patients (>65 years): Reduce initial bolus to 10-15 mg due to increased sensitivity and slower drug clearance 1
• Patients with cardiac or respiratory disease: Start with 10-15 mg boluses and titrate cautiously, as propofol causes dose-dependent decreases in cardiac output, systemic vascular resistance, and arterial pressure 1
• Hemodynamically unstable patients: Avoid loading doses entirely, as propofol produces negative cardiac inotropy 1

Propofol Maintenance Infusion

For ICU sedation requiring continuous infusion, most adult patients require maintenance rates of 5-50 mcg/kg/min (0.3-3 mg/kg/h). 1

• Light sedation (Ramsay 2-3): Target plasma concentrations of 0.25-0.6 mcg/ml, corresponding to approximately 5-20 mcg/kg/min 4
• Moderate sedation (Ramsay 4): Target plasma concentration of 1.0 mcg/ml, corresponding to approximately 20-40 mcg/kg/min 4
• Never exceed 70 mcg/kg/min or use prolonged high-dose infusions without monitoring for propofol infusion syndrome (PRIS) 1

Critical Dosing Distinction

• Do not confuse procedural sedation total doses (expressed in mg) with continuous infusion rates (expressed in mg/kg/h) 1
• For short procedures (20-40 minutes), typical cumulative propofol doses are 35-100 mg total, delivered as intermittent boluses—not as a continuous hourly infusion 1, 2

Fentanyl Dosing for Analgesia

Propofol has zero analgesic properties; therefore, fentanyl 50-100 mcg should be co-administered for painful procedures. 1, 2, 3

• Standard fentanyl dose for procedural sedation: 50-100 mcg IV 1, 2
• For combination therapy with propofol: 25-75 mcg fentanyl allows for 50-75% reduction in total propofol requirements 3
• Elderly patients or those with respiratory disease: Reduce fentanyl to 25-50 mcg and titrate cautiously, as the combination produces synergistic respiratory depression 3

Typical Combination Regimen

• Administer fentanyl 50-100 mcg first, wait 2-3 minutes for peak effect 3
• Then begin propofol with reduced initial bolus of 10-20 mg 1, 2
• Titrate propofol in 10-20 mg increments every 20-30 seconds to desired sedation 2

Mandatory Monitoring Requirements

Continuous monitoring of heart rate, blood pressure, and pulse oximetry is essential during all propofol administration. 1, 2

• Pulse oximetry with supplemental oxygen administration is mandatory for all patients 1, 2
• Blood pressure monitoring at minimum every 2-5 minutes 3
• A dedicated healthcare provider should monitor the patient and administer drugs, performing no other tasks 3
• Have reversal agents (naloxone for fentanyl) and airway management equipment immediately available 3

Expected Adverse Events

• 5-10% of patients experience transient oxygen desaturation <90%, typically responding to jaw thrust or brief bag-mask ventilation 2
• Clinically insignificant hypotension (systolic BP decrease of 10-15 mmHg) occurs commonly but rarely requires intervention 2
• Approximately 5-7% may experience transient desaturation below 90% 1

Common Pitfalls to Avoid

• Never administer propofol loading doses in hemodynamically unstable patients 1
• Avoid rapid bolus dosing—this markedly increases risk of hypotension and respiratory depression 3
• Do not use propofol alone for painful procedures—it has no analgesic effect and requires opioid co-administration 1, 2
• Propofol is contraindicated in patients with allergies to egg, soy, or sulfite 1, 2
• Account for propofol's caloric contribution (1.1 kcal/ml from lipid emulsion) when calculating nutritional requirements in ICU patients 1
• When combining propofol with fentanyl, recognize that synergistic respiratory depression exceeds either drug alone—reduce doses of both agents 3