Nurse-controlled analgesia (NCA) following major surgery in 10,000 patients in a children's hospital.

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.

Developmental regulation of codeine analgesia in the rat.

BACKGROUND: Codeine analgesia is dependent on metabolism to morphine. Metabolic capability is genetically determined in rats and humans, and individuals can be classified as extensive or poor metabolizers, as determined by the extent of production of morphine. Codeine is often given to infants and children. The aim of this study was to investigate the effects of developmental age on codeine analgesia in rats. METHODS: The effects of codeine were compared with those of morphine using withdrawal reflex responses to mechanical stimuli (with and without inflammation) and to noxious heat in two strains of rats (Sprague-Dawley and Dark Agouti) that have been used to model human metabolic phenotypes because of marked differences in enzyme activity. Effects of the opioids were compared at 3, 10, and 21 days of age and in adult rats. RESULTS: Consistent age-related changes in the efficacy of codeine relative to morphine were noted for both strains of rats. For the extensive metabolizer (Sprague-Dawley) strain, codeine efficacy was substantially lower at 3 days of age (P < 0.001), but there was no difference between the effects of codeine and morphine for 10- and 21-day-old rats and adults (P > 0.05). Poor metabolizers (Dark Agouti strain) also had comparatively low efficacy for codeine compared with morphine in 3-day-old rats and in adults (P < 0.001). In 10- and 21-day-old Dark Agouti rats, there was no difference between either drug (P < 0.05). CONCLUSIONS: Codeine analgesia is developmentally regulated, with low efficacy in the early postnatal period. Effects in the adult rat were not predictive of efficacy in development in either strain, which has important implications for further study and, possibly, for clinical use.