Propofol versus étomidate en chirurgie urologique de courte durée

Abstract

Thirty patients, scheduled for short urological surgical procedures and ranked ASA 1 or 2, were randomly assigned to two homogenous groups. In group P, they were given a 2 mg · kg −1 bolus of propofol and 10 μg · kg −1 of alfentanil, followed by a continuous infusion of propofol (5 mg · kg −1 · h −1) and 5 μg · kg −1 doses of alfentanil. In group E, they were given a 0.3 mg · kg −1 bolus of etomidate, followed by an infusion (1.5 mg · kg −1 · h −1). The doses of alfentanil were the same as in group P. Further doses of either propofol (0.5 mg · kg −1) or etomidate (0.2 mg · kg −1) were used should anaesthesia prove not to be deep enough. The patients were not intubated, and breathed spontaneously. Surgery lasted a mean of 18.3 ± 11.8 min (group P) and 18.8 ± 9.4 min (groupe E). The following parameters were studied : the amount of each agent required for maintenance of anaesthesia, the duration of apnoea at induction, the quality of anaesthesia and of muscle relaxation, adverse effects (coughing, trismus, restlessness, nausea, vomiting), the time required for recovery, and its quality. In group P, there was a 27 % decrease in arterial pressure, without any tachycardia or hypoxia, together with a quick recovery of excellent quality. On the other hand, in group E, there was little or no haemodynamic alteration, but there often was a trismus at induction. Hypoxia also occurred during induction with etomidate, being severe enough in one case to require tracheal intubation and artificial ventilation. The reasons for this hypoxia seemed to be the apnoea and the trismus, which tends to hinder assisted ventilation. It would therefore seem that the propofol protocol studied should be kept for young patients, because they tolerate arterial hypotension better. It should be used with caution in elderly patients. Changes in technique and doses should be made to the two protocols tested before using them for other indications.