MANUAL COMPARED WITH TARGET-CONTROLLED INFUSION OF PROPOFOL

We studied 160 ASA I-II patients, anaesthetized with propofol by infus ion, using either a manually controlled or target-controlled infusion system. Patients were anaesthetized by eight consultant anaesthetists who had little or no previous experience of the use of propofol by inf usion. In addition to propofol, patients received temazepam premedicat ion, a single dose of fentanyl and 67% nitrous oxide in oxygen. Each c onsultant anaesthetized 10 patients in sequential fashion with each sy stem. Use of the target-controlled infusion resulted in more rapid ind uction of anaesthesia and allowed earlier insertion of a laryngeal mas k airway. There was a tendency towards less movement in response to th e initial surgical stimulus and significantly less movement during the remainder of surgery. Significantly more propofol was administered du ring both induction and maintenance of anaesthesia with the target-con trolled system. This was associated with significantly increased end-t idal carbon dioxide measurements during the middle period of maintenan ce only, but recovery from anaesthesia was not significantly prolonged in the target-controlled group. With the exception of a clinically in significant difference in heart rate, haemodynamic variables were simi lar in the two groups. Six of the eight anaesthetists found the target -controlled system easier to use, and seven would use the target-contr olled system in preference to a manually controlled infusion. Anaesthe tists without prior experience of propofol infusion anaesthesia quickl y became familiar with both manual and target-controlled techniques, a nd expressed a clear preference for the target-controlled system.