What is the recommended dose of morphine (opioid analgesic) for wound debridement?

Morphine Dosing for Wound Debridement

For wound debridement, the recommended dose of intravenous morphine is 0.1 mg to 0.2 mg per kg administered every 4 hours as needed for pain management, with dose adjustments based on pain severity, adverse events, and patient characteristics. 1

Adult Dosing Guidelines

Intravenous Administration (Preferred for Severe Pain)

• Initial dose: 0.1-0.2 mg/kg IV 1
• For opioid-naïve adults: 2-10 mg IV 2
• Titration: Can be administered every 15 minutes as needed for breakthrough pain 2
• Oral-to-IV conversion ratio: 1:3 (divide oral dose by 3 for IV equivalent) 3, 2

Subcutaneous Administration (Alternative when IV access unavailable)

• Oral-to-subcutaneous conversion ratio: 1:2 2
• Can be given as bolus injections every 4 hours or as continuous infusion 2

Pediatric Dosing Guidelines

For pediatric patients undergoing wound debridement, age-based dosing is recommended:

• < 3 months: 25-50 micrograms/kg every 4-6 hours 3
• 3-12 months: 50-100 micrograms/kg every 4-6 hours 3
• 1-5 years: 100-150 micrograms/kg every 4-6 hours 3
• 5-18 years: 200-300 micrograms/kg (max 10mg) as a single dose adjusted according to response 3

Administration Considerations

Timing and Efficacy

• IV morphine provides significantly faster onset of analgesic effect compared to IM (5 minutes vs. 20 minutes) 4
• Efficacy should be assessed every 15 minutes for IV administration 2
• Complete anesthesia may be required for extensive debridement procedures as morphine alone may be insufficient for severe burn wound debridement 5

Safety Monitoring

• Monitor for respiratory depression, especially with high doses or parenteral administration 2
• Have naloxone available to reverse accidental overdose 2
• Monitor sedation levels, as sedation is a common side effect during IV morphine titration 6
• Observe vital signs, particularly respiratory rate and oxygen saturation

Special Populations

Renal Impairment

• Use with extreme caution in patients with renal impairment 2
• For severe renal impairment (eGFR <30 mL/min):
  • Reduce dose by 50-75% and extend dosing interval 2
  • Consider alternative opioids such as fentanyl or buprenorphine 2

Elderly Patients

• Start at the lower end of the dosing range 2, 1
• Carefully monitor for side effects 2
• May require dose reduction due to decreased clearance

Management of Side Effects

• Constipation: Prophylactic laxatives (stimulant laxative with or without stool softener) should always be prescribed 2
• Nausea/Vomiting: Consider prophylactic antiemetics (metoclopramide or antidopaminergic drugs) for the first few days 2
• Sedation: Usually resolves within a few days of stable dosing 2

Adjunctive Therapy Considerations

Consider adjunctive medications to reduce morphine requirements:

• Gabapentin (1200mg single oral dose 2 hours before procedure) has been shown to reduce postoperative morphine consumption and pain scores after surgical debridement in burn patients 7
• Local anesthetics for wound infiltration may reduce systemic opioid requirements 3

Common Pitfalls to Avoid

1. Dosing errors: Take care to avoid confusion between different concentrations and between mg and mL 1
2. Respiratory depression: Rapid IV administration may result in chest wall rigidity 1
3. Oversedation: Do not mistake sedation for pain relief 6
4. Inadequate analgesia: For extensive burn wound debridement, morphine alone may be insufficient and complete anesthesia might be required 5