Background and objectives: Patients who received NCA with morphine following major surgery between 1996 and 2008 at Great Ormond Street Hospital, London, UK, were prospectively studied in the postoperative period to determine effectiveness, morphine requirements, incidence of common side effects, and serious adverse events.
Methods: The morphine NCA regimen and monitoring was according to standard hospital protocols. Data were collected prospectively and subsequently entered by trained personnel into a secure database. Patient demographics, effectiveness and satisfaction rates, morphine requirements, side effects, and serious complications were recorded.
Results: 10,079 patients were included. The average age was 4 years old (range 1 day to 20.5 years, median 2.3 years). There were 510 neonates. The average NCA duration was 43.7 h. 1.8% of morphine NCAs were replaced by other methods because analgesia was unsatisfactory. Satisfaction ratings were 'good' or 'very good' for 98% of the remainder. Average daily morphine requirement (mcg x kg(-1) x h(-1)) was related to age, surgical category, and postoperative time. Side effects included PONV (25%), itching (9.4%), depression of respiration, and sedation (4.5%); incidences varied with age, morphine dose, and type of surgery. Serious, potentially life-threatening adverse effects (SAE) were 0.4%. There were no deaths. SAE were significantly greater in neonates (2.5%), relative risk 9.4, P < 0.001. Morphine dose in neonates who experienced SAE was not significantly different from other neonates.
Conclusion: NCA with morphine is an acceptable, safe, and effective method of postoperative analgesia for a wide range of ages and types of surgery in our practice. Morphine requirements increase with age, but there was also considerable inter-individual variation within age groups. PONV, itching, sedation, and respiratory depression are expected side effects. SAE are uncommon but the incidence is greatest in neonates.