Comparison of local infiltration of tenoxicam and intravenous tenoxicam for postoperative analgesia in herniorrhaphy.

BACKGROUND: The major complaint of herniorrhaphy is postoperative pain which occurs during the first 24 h after operation. Tenoxicam has a long half-life of 60-80 h. Local infiltration of the drug concentrates the pain control effects in the local area. The local infiltration dose can be smaller than the recommended systemic dose needfully to reach the target area to be effective. Therefore we studied the effect of preoperative local infiltration of tenoxicam on postoperative pain. METHODS: Sixty patients, belonging to ASA classes I and II, undergoing unilateral herniorrhaphy, were randomly assigned to 4 groups. General anesthesia was induced with thiamylal 5 mg/kg, fentanyl 2 micrograms/kg, and atracurium 5 mg/kg. Group 1 (G1) patients were preoperatively injected with 10 mg of tenoxicam in 10 ml normal saline or distilled water, in the operative area. Group 2 (G2) and Group 3 (G3) patients were preoperatively given intravenous tenoxicam, 20 mg and 10 mg, respectively. Group 4 (G4) patients were not given preoperative local infiltration or intravenous tenoxicam to serve as control group. The pain score was assessed at 2 h, 9 h, 24 h postoperatively in all groups. We recorded the total amount of acetaminophen used and the form of administration of the analgesic drug. All patients received general anesthesia in uniform technique. RESULTS: Pain score and amount of analgesic drug required in G1 (local infiltration group) patients were significantly decreased compared with the other groups. The postoperative pain score of Visual Analog Scale (VAS) and analgesic requirement in the four groups were ranked as follows: G1 < G2 < G3 < G4. No significant difference was observed between G2, G3 and G4. Only the pain score in G2 patients significantly decreased (p < 0.05) during the late postoperative period (24 h) when compared with G4 patients. CONCLUSIONS: Preoperative local infiltration of tenoxicam can decrease postoperative pain score significantly during the most painful period (24 h) in herniorrhaphy.