thromboxane-a2 and Pain--Postoperative

The major benefits of the perioperative administration of nonsteroidal anti-inflammatory drugs (NSAIDs) are related to the ability of these agents to provide analgesia without cardiovascular or respiratory depression. However, there are several possible adverse effects of NSAIDs. All NSAIDs reduce the synthesis of prostaglandins by the kidneys, but their administration in the perioperative period appears to have little potential for renal toxicity when adequate hydration is maintained and renal function is not dependent on renal prostaglandins. However, NSAIDs may cause impairment of renal function in patients with conditions such as hypovolaemia, congestive cardiac failure, or hepatic cirrhosis, since renal function in these patients may be dependent on the vascular effects of prostaglandins. Platelet aggregation is inhibited by the administration of NSAIDs, and most studies of their haematological effects report that NSAIDs are associated with an increase in bleeding times. In patients with normal haemostatic function before NSAID administration, almost all indices of coagulation remain within the normal range after NSAID treatment. Most studies of perioperative blood loss have reported no significant difference between the effects of NSAIDs and placebo in this regard. The incidence of major allergic reactions in the general population appears to be small with NSAIDs. Overall, NSAIDs appear to be safe and well tolerated drugs with a valuable role to play in the treatment of postoperative pain.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Drug Hypersensitivity; Hemorrhage; Humans; Kidney; Pain, Postoperative; Platelet Aggregation; Postoperative Complications; Prostaglandins; Thromboxane A2

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.

Topics: 6-Ketoprostaglandin F1 alpha; Adult; Ambulatory Surgical Procedures; Anesthesia, Dental; Anesthesia, General; Diclofenac; Double-Blind Method; Epoprostenol; Female; Humans; Injections, Intravenous; Isoflurane; Male; Oral Hemorrhage; Pain, Postoperative; Random Allocation; Thromboxane A2