What is the proper method to prepare a morphine sulfate infusion for an adult, including dilution to 0.1 mg/mL, infusion rate calculation, labeling, monitoring, and safety precautions?

Morphine Infusion Preparation Protocol

Prepare morphine sulfate infusion by diluting to 0.1 mg/mL concentration using normal saline or D5W, calculate the infusion rate based on the patient's total daily morphine requirement divided by 24 hours, and implement continuous monitoring for respiratory depression with naloxone immediately available.

Standard Dilution Method

• Dilute morphine sulfate to a standard concentration of 0.1 mg/mL (100 mcg/mL) for continuous infusion to minimize calculation errors and ensure consistent dosing 1
• Use either normal saline (0.9% NaCl) or 5% dextrose in water (D5W) as the diluent, as both are compatible with morphine sulfate 2
• For example, to prepare 100 mL of 0.1 mg/mL solution: add 10 mg of morphine sulfate to 100 mL of diluent 1

Infusion Rate Calculation

• Calculate the hourly infusion rate by dividing the patient's total 24-hour morphine requirement by 24, then adjust the pump to deliver this amount per hour 1, 2
• For opioid-naïve patients starting continuous infusion, begin with 5-10 mg parenteral morphine as the starting 24-hour dose (approximately 0.2-0.4 mg/hour), which is equivalent to 20-40 mg oral morphine 1
• The IV to oral morphine potency ratio is 1:3, meaning 1 mg IV morphine equals approximately 3 mg oral morphine 3

Initial Titration for Severe Dyspnea or Pain

• Administer bolus IV injections of 1-2 mg morphine every 5-10 minutes until the patient reports relief, then start continuous infusion at an hourly rate equal to 50% of the cumulative bolus dose 2
• For example, if 10 mg total bolus was required for relief, start infusion at 5 mg/hour 2
• Monitor vital signs, degree of sedation, and oxygen saturation continuously during titration 2

Labeling Requirements

• Label the infusion bag clearly with: drug name (morphine sulfate), concentration (0.1 mg/mL), total volume, date and time prepared, expiration date/time, and patient identifiers 1
• Include "HIGH ALERT MEDICATION" warning on the label to prevent medication errors 1
• Document the preparation details in the patient's medical record 1

Monitoring Parameters

• Assess respiratory rate, oxygen saturation, sedation level, and pain score every 15 minutes during initial titration, then hourly once stable 2
• Respiratory rate less than 10 breaths per minute warrants immediate intervention and consideration of naloxone 1
• Monitor for common side effects including sedation, nausea, constipation, and confusion 1
• Serial blood gas monitoring may be indicated in patients with severe respiratory compromise, though PaCO2 may increase and pH may decrease without necessarily indicating treatment failure 2

Breakthrough Dosing Protocol

• Provide breakthrough doses equivalent to 10-20% of the total 24-hour morphine dose for transient pain exacerbations 1, 4
• Administer breakthrough doses IV every 15 minutes as needed for adequate pain control 1
• If more than 3-4 breakthrough doses are required per 24 hours, increase the baseline continuous infusion rate by 25-50% 1, 4

Safety Precautions and Naloxone Availability

• Keep naloxone immediately available at the bedside: for adults, prepare 0.4-2 mg IV/IO, diluted in normal saline, administered every 30-60 seconds until respiratory improvement 1
• For opioid-induced respiratory depression, use lower naloxone doses (1-15 mcg/kg) to reverse respiratory depression while maintaining analgesia 1
• Avoid naloxone in patients with long-term opioid use due to risk of acute withdrawal and seizures 1
• Patients should be observed continuously for at least 2 hours after the last naloxone dose, as respiratory depression may recur 1

Management of Sedation

• If excessive sedation occurs, temporarily discontinue the morphine infusion until mental status improves, then restart at 50% of the previous hourly dose 2
• Sedation typically resolves within days during dose titration and does not necessarily require dose reduction if pain control is adequate 5

Prophylactic Supportive Care

• Institute a stimulant laxative regimen in all patients receiving continuous morphine infusion unless contraindicated, as constipation is universal with opioid therapy 5, 4
• Consider prophylactic antiemetics for patients with history of nausea or vomiting 5
• Psychostimulants may be used to counteract persistent drowsiness without compromising analgesia 1

Common Pitfalls to Avoid

• Never use extended-release morphine formulations for continuous IV infusion—only immediate-release morphine sulfate injection is appropriate 6, 7
• Do not assume a fixed maximum dose exists; morphine has no ceiling effect, and the appropriate dose is determined by balancing analgesia against side effects 5, 7
• Avoid dose stacking by waiting appropriate intervals (15 minutes IV) between bolus doses during titration 1
• Do not mix morphine with glucose-containing solutions if phenytoin will be administered through the same line, as precipitation may occur 1