Opioid Analgesic (Patient-Controlled Analgesia) Pregnancy: C (D if prolonged use/near delivery)

Morphine PCA (Burns Pain)

Brand names: Morphine Sulphate PCA

Adult dose

Dose: PCA: 1 mg bolus IV with 5-minute lockout; background infusion: 1–2 mg/h (burns); titrate to NRS ≤3

Route: intravenous (PCA device)

Frequency: As demanded by patient (PCA bolus)

Max: 20–30 mg/4h (review if exceeding)

Burns: PCA preferred over PRN nurse-administered for dressing changes and background pain; continuous low-dose background infusion considered in burns >20% TBSA

Paediatric dose

Dose: 0.02 mg/kg

Route: IV

Frequency: PCA bolus every 5–10 min lockout

Max: 0.2 mg/kg/4h

Concentration: 1 mg/mL for PCA (weight-adjusted) mg/ml

Paediatric PCA ≥5 years (able to understand concept): 0.02 mg/kg bolus, 5-10 min lockout; NCA (nurse-controlled analgesia) for younger children

Dose adjustments

Renal

Reduce dose and increase interval if eGFR <30 ml/min (active metabolite accumulation)

Hepatic

Reduce dose in severe hepatic impairment

Paediatric weight-based calculator

Patient weight (kg)

Paediatric PCA ≥5 years (able to understand concept): 0.02 mg/kg bolus, 5-10 min lockout; NCA (nurse-controlled analgesia) for younger children

Clinical pearls

PCA advantage in burns: patient autonomy reduces anxiety; titrates to individual need; lower total opioid dose vs. PRN
Opioid tolerance common in burns due to prolonged opioid exposure — dose escalation often needed; consider opioid rotation
PAEDIATRIC DOSE SAFETY: PCA bolus is 0.02 mg/kg once per demand — NOT mg/kg/kg

Contraindications

Respiratory depression
Raised ICP
Concurrent MAOIs
Inability to operate PCA device (use NCA)

Side effects

Respiratory depression
Sedation
Nausea/vomiting
Constipation
Pruritis
Urinary retention
Dependence

Interactions

Benzodiazepines (respiratory depression — FDA black box warning)
CNS depressants
MAOIs (serotonin syndrome — 14-day washout)

Monitoring

NRS pain scores
Sedation score
Respiratory rate
SpO2
Cumulative 4-hourly dose review

Reference: BNFc; BNF 86; BBA pain management guidelines; RCoA PCA standards. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators