[The preemptive action of ketoprofen. Randomized, double-blind study with gynecologic operations]

Ketoprofen exerts its clinical effect by inhibition of prostaglandin synthesis, but also acts as an NMDA-receptor antagonist by means of the kynurenic acid. Based on ketoprofen's supposed central mechanism of analgesia, we expected a preemptive effect, which was assessed by the present study.

In a prospective, randomised, double-blind investigation of 48 patients undergoing gynaecological procedures (laparotomy, pelvioscopy), the first group received ketoprofen 2 mg/kg body weight i.v. 20 min before the beginning of surgery and placebo i.v. at the end of surgery. In the second group, placebo was administered first and ketoprofen at the end of surgery. Premedication and anaesthesia were standardised by protocol. The postoperative analgesic patient-controlled analgesia consumption by was also standardised (piritramide). Efficacy was assessed by visual analogue scale (VAS) and total requirement of analgesics within the first 24 postoperative hours. The time to the first request for postoperative analgesics was also recorded. Safety was assessed by continuous monitoring of vital parameters such as respiratory rate, heart rate, blood pressure, and oxygen saturation. The incidence and severity of adverse events was documented.

There were no significant differences between the groups in demographic data or type or duration of surgery. The time to the first request for analgesic, VAS pain intensity, and analgesic consumption in the first 24 h post-surgery were not significantly different between the groups (t-test).

Ketoprofen is an effective post-operative analgesic in combination with an opioid, but has no preemptive effect according to the results of this study.