A trial of pre-emptive analgesia. Influence of timing of peroperative alfentanil on postoperative pain and analgesic requirements

Abstract

The influence of timing of administration of peroperative alfentanil on pain and analgesic requirements after surgery was studied in 60 patients undergoing total abdominal hysterectomy with or without bilateral salpingo-oophorectomy. Thirty patients received alfentanil 7.5 micrograms.kg-1 on induction of anaesthesia, followed by alfentanil 7.5 micrograms.kg-1 90 s before surgical incision (group A). Thirty control patients received alfentanil 15 micrograms.kg-1, 10 min after abdominal incision (group B). In addition, 10 min after surgical incision both groups received morphine 0.2 mg.kg-1, given over a 10 min period. The visual analogue scores (median, interquartile range) for pain 24 h after operation were 28.5 mm (11.25-47.0) in group A and 21.0 mm (10.5-47.5) in group B, p = 0.76. There were no differences in visual analogue scores at intermediate times. Morphine consumption in the first 24 h after surgery (median, interquartile range) was 53.5 mg (37.25-60.0) in group A and 52.0 mg (39.75-71.0) in group B, p = 0.52. We conclude that postoperative morphine consumption and pain scores are no different when alfentanil 15 micrograms.kg-1 is given before or after skin incision for abdominal hysterectomy.