Local analgesia for infant pyloromyotomy. Does wound infiltration with bupivacaine affect postoperative behaviour?

A series of 20 infants undergoing general anaesthesia for pyloromyotomy were studied in a randomised, blind and controlled trial to determine the postoperative behavioural and cardiorespiratory effects of wound infiltration of bupivacaine. Ten infants received bupivacaine (0.6 ml/kg, 0.25% = 1.5 mg/kg) injected intradermally into the wound during general anaesthesia and 10 infants received general anaesthesia only. Postoperatively, an independent observer assessed conscious level, crying, posture and facial expression using a simple numerical scoring system, and also recorded heart and respiratory rates over a 2-h period. Infants who had received bupivacaine were observed to have higher respiratory rates and behaviour scores, although these differences were not statistically significant. These results indicate that wound infiltration with bupivacaine offers no obvious advantage to infants following pyloromyotomy.