IV Morphine Continuous Infusion Preparation Guidelines
For a continuous 24-hour infusion of IV morphine 2-5 mg, the recommended preparation is to dilute the morphine in 50-100 ml of either D5W or PNSS (0.9% Sodium Chloride Solution).
Preparation Guidelines
Standard Dilution
- For continuous infusion of morphine over 24 hours, dilute 2-5 mg of morphine in:
Concentration Considerations
- The resulting concentration should be low enough to allow for precise titration but high enough to limit fluid volume
- For a 24-hour infusion:
- 2 mg in 50 ml = 0.04 mg/ml concentration
- 5 mg in 100 ml = 0.05 mg/ml concentration
Administration Guidelines
Infusion Rate
- Calculate the hourly rate based on the total daily dose:
- For 2 mg/24 hours = 0.083 mg/hour
- For 5 mg/24 hours = 0.208 mg/hour
- Adjust the infusion pump accordingly:
- 2 mg in 50 ml = 2.1 ml/hour
- 5 mg in 100 ml = 4.2 ml/hour
Monitoring Parameters
- Monitor vital signs every 15 minutes for the first hour, then hourly for 4 hours, then every 4 hours 2
- Assess pain scores every 30-60 minutes until stable, then every 4 hours
- Monitor sedation level using a standardized scale
- Ensure respiratory rate remains ≥8/min to continue infusion 2, 3
Clinical Considerations
Compatibility
- Morphine is compatible with both D5W and PNSS 1
- D5W is often preferred for opioid infusions based on clinical practice guidelines 1
- Avoid mixing with alkaline solutions which may cause precipitation
Safety Precautions
- Bradypnea (respiratory rate <10/min) with marked somnolence indicates the need for dose reduction 3
- Continuous IV morphine is generally safe when properly monitored, but requires vigilance for respiratory depression 3, 4
- Higher concentrations may be needed for patients requiring fluid restriction, but this increases the risk of dosing errors 5
Breakthrough Pain Management
- For breakthrough pain during continuous infusion, a bolus dose of approximately twice the hourly infusion rate may be considered 2
- Allow at least 15 minutes between bolus doses to assess effect 2, 6
Special Populations
- For elderly patients or those with renal/hepatic impairment, consider using the lower end of the dosing range (2 mg/24 hours)
- Pediatric dosing requires weight-based calculations and is typically more conservative
By following these guidelines, continuous IV morphine infusions can be safely administered while minimizing risks of respiratory depression and ensuring adequate pain control.