The safety of topical anaesthetic and analgesic agents in a gel when used to provide pain relief at split skin donor sites

Post operative pain from split skin donor sites is a recognised problem. This study was carried out to assess the safety of a 'depot' preparation of bupivacaine and ketoprofen when applied to denuded dermis of a split donor site. Two groups of six patients each received either bupivacaine gel (2.5 mg/ml) or ketoprofen gel (1.6 mg/ml). One patient from each group was excluded as protocol was not followed. The mean surface area for bupivacaine was 106 cm2 (range 64-160) and the mean for ketoprofen was 130 cm2 (range 64-180). Blood samples were obtained before application and at 10, 20, 30, 60, 120, 240 and 480 min after application. Serum levels were assayed using Gas Liquid Chromatography and High Pressure Liquid Chromatography. Bupivacaine levels peaked at 120 min, mean level obtained was 0.07 microgram/ml (range 0.03-0.1). Ketoprofen levels also peaked at 120 min and the mean level obtained was 0.20 microgram/ml (range 0.12-0.27). The reported toxic serum level for bupivacaine was 4 micrograms/ml and for ketoprofen is 1128 micrograms/ml. In conclusion, these preparations, when applied to denuded dermis of a split skin donor site, are unlikely to result in toxic levels.

Dose-response curves for suxamethonium in neonates, infants and children

Single dose-response curves were determined for suxamethonium in neonates, infants and children during thiopentone-fentanyl-nitrous oxide anaesthesia. During onset of neuromuscular block, suxamethonium produced an increase in muscle tone which was greatest in neonates and infants. The dose-response curves for the three groups were parallel. The effective doses producing 90% depression of twitch height were significantly greater in neonates and infants compared with children (517 and 608 v. 352 micrograms kg-1). These values were greater than those obtained in a comparable study in adults. In view of their higher ED values compared with adults and a marked individual variability in response to small doses of suxamethonium, we recommend an intubating dose of 3 mg kg-1 for neonates and infants and 2 mg kg-1 for children. These doses are 50-100% greater than those previously recommended for paediatric patients.

Recovery after single-breath halothane induction of anaesthesia in daycase patients. A comparison with thiopentone

A single-breath technique of inhalational induction of anaesthesia allows intravenous induction agents to be avoided. We have investigated recovery from anaesthesia in 40 daycase patients, using tests of psychomotor function. Patients anaesthetised with inhalational induction awaken earlier than those who receive thiopentone, but not significantly earlier. There were no significant differences in postoperative psychomotor function between patients who received thiopentone and those who had inhalational inductions. Single-breath halothane, nitrous-oxide, oxygen induction is an alternative to intravenous induction in cooperative adults, but does not confer significant benefits in terms of recovery.