What is the recommended preparation and administration protocol for fentanyl (synthetic opioid) infusion?

Fentanyl Infusion Preparation and Administration Protocol

For opioid-naïve patients, administer an initial bolus of 1-2 mcg/kg IV fentanyl slowly over several minutes, followed by a continuous infusion individualized based on response, with breakthrough boluses of 25-50 mcg available every 5 minutes. 1

Initial Bolus Dosing

Critical administration rule: Always administer IV fentanyl slowly over several minutes to prevent glottic and chest wall rigidity, which can occur with doses as low as 1 mcg/kg when given rapidly. 2, 1

Opioid-Naïve Patients

• Start with 1-2 mcg/kg IV as initial bolus 2, 1
• Allow 2-3 minutes for fentanyl to take effect before administering additional medications 2

Special Populations

• Brain-injured patients requiring intubation: Use higher bolus doses of 3-5 mcg/kg, but reduce in hemodynamically unstable patients 2, 1
• Elderly patients: Reduce doses by 50% or more 1

Starting Continuous Infusion

After achieving initial pain control with boluses, initiate the continuous infusion with the rate individualized based on the patient's response to initial boluses. 1

Dose Escalation Algorithm

• If patient requires two bolus doses within one hour: Double the infusion rate 2, 1
• Reassess after 2-3 days at steady state and adjust basal infusion rate based on average daily breakthrough medication requirements 2

Breakthrough Dosing Protocol

• Order IV fentanyl bolus doses of 25-50 mcg every 5 minutes as needed for breakthrough pain 1
• For patients already on fentanyl infusion with new pain or respiratory distress: Give a bolus dose equal to two times the hourly infusion rate 1

Converting from Other Opioids to Fentanyl Infusion

From Morphine

Use a fentanyl:morphine potency ratio of 60:1. 2, 1

Conversion algorithm:

1. Calculate the 24-hour morphine dose
2. Multiply by 1/60 to get the fentanyl dose
3. Divide by 4 to correct for morphine's longer half-life
4. Reduce the calculated dose by 25-50% to account for incomplete cross-tolerance 2, 1

From Other Opioids

• Calculate total 24-hour opioid requirement 2
• Use equianalgesic conversion tables 2
• Always reduce calculated dose by 25-50% if pain was well-controlled 2, 1

Critical Safety Monitoring

Monitor patients for at least 24 hours after dose initiation or increase due to fentanyl's mean half-life of approximately 17 hours. 2, 1

Essential Preparations

• Be prepared to administer naloxone (0.1 mg/kg IV or 0.2-0.4 mg for adults) at all times 2, 1
• Have respiratory support equipment immediately available 2, 1
• Monitor oxygen saturation continuously 2
• Have vasoconstrictors (ephedrine or metaraminol) immediately available to treat hypotension 2

High-Risk Drug Interactions

There is significantly increased risk of apnea when fentanyl is combined with benzodiazepines or other sedatives—exercise extreme caution with co-administration. 2, 1

Common Pitfalls to Avoid

• Never administer fentanyl rapidly: Chest wall rigidity can occur with doses as low as 1 mcg/kg when given too quickly 1
• Starting with too high a conversion dose from other opioids can lead to respiratory depression; always reduce by 25-50% for incomplete cross-tolerance 1
• Respiratory depression may last longer than the analgesic effect of fentanyl, requiring extended monitoring 1
• Avoid morphine in patients with renal failure due to accumulation of renally cleared metabolites; fentanyl is preferred in this population 1

Dose Adjustments Based on Patient Factors

• Adjust doses based on size, age, and organ dysfunction 1
• Reduce doses by 50% or more in elderly patients 1
• In hemodynamically unstable patients, reduce initial bolus doses 2, 1