Is intra-articular pethidine an alternative to local anaesthetics in arthroscopy? A double-blind study comparing prilocaine with pethidine.

We investigated the per- and postoperative pain-reducing effect of pethidine given intra-articularly (i. art.). Thirty patients subjected to knee joint arthroscopy, diagnostic and surgical procedures, were randomly assigned to one of three groups. Group A consisted of ten patients who received 250 mg prilocaine + 200 micrograms adrenaline (i. art.) in a volume of 50 ml, group B of ten patients who received 200 mg pethidine (i. art.) in 50 ml saline, and group C of ten patients who received 200 mg pethidine + 200 micrograms adrenaline (i. art.) in 50 ml saline. During arthroscopy the patients reported on pain intensity and discomfort using visual analogue scales. Ratings were low and did not differ significantly between the three groups. Two of three patients in each group requested additional analgesics or sedatives due to pain and discomfort, but again with no difference between the three groups. Postoperatively all patients rated their pain intensity at rest and during movement (at 0, 1, 2, 3, 4, 5, 6, 12 and 24 h). The patients receiving pethidine (group B) reported significantly less pain at rest and movement than group A patients, in general at 1-4 h postoperatively. A significant difference was detected between groups B and C at 4 h postoperatively. Calculating the total sum of pain scores, patients receiving pethidine (group B) reported significantly less pain both at rest and during movement than those receiving prilocaine (group A). Furthermore, patients in group B used significantly less analgesics than those in group A. Adrenaline did not potentiate the effect of pethidine.(ABSTRACT TRUNCATED AT 250 WORDS)