Intravenous Diclofenac Sodium Decreases Prostaglandin Synthesis and Postoperative Symptoms After General Anaesthesia in Outpatients Undergoing Dental Surgery

One hundred unpremedicated patients scheduled for outpatient restorative dentistry and/or oral surgery were given either 75 mg diclofenac sodium (prostaglandin synthesis inhibitor) or a saline placebo i.v. in a double-blind random fashion before induction of anaesthesia with methohexitone (2 mg/kg). Intubation was facilitated with suxamethonium (1.2 mg/kg) and anaesthesia was maintained with isoflurane in 50% nitrous oxide and oxygen using spontaneous respiration. Cuff pressure was continuously monitored and maintained at 10-25 mmHg. The mean duration of anaesthesia was 141 +/- 75 min in the diclofenac group and 150 +/- 73 min in the saline group. Diclofenac inhibited prostaglandin synthesis, as evident from serum thromboxane B2 and urinary 6-keto-prostaglandin F1 alpha data. There was no difference in recovery as assessed from the orientation time (14.2 +/- 5.7 min and 14.5 +/- 6.3 min for diclofenac and saline patients, respectively), perceptual speed and ability to walk along a straight line 30 and 60 min after anaesthesia. Emetic symptoms were equally common in both groups: an overall incidence of 32.6% and 36.7% for the diclofenac and saline patients, respectively. In the whole patient series women became nauseated and vomited more than men (P less than 0.01). Diclofenac reduced the incidence of pain in the throat or oral region 1 h after anaesthesia (P less than 0.05) and other symptoms 1-24 h postoperatively (P less than 0.01). Thus, preoperative intravenous diclofenac appears useful in ambulatory patients undergoing restorative dentistry and oral surgery under isoflurane anaesthesia.