Postoperative analgesia in herniorrhaphy with local anesthesia and monitored anesthesia care

Summary

In this study the authors evaluated the grade of acceptance and the operating conditions of unilateral primary herniorrhaphy under local anesthesia and monitored anesthesia care (MAC). The amount of pain in the immediate postoperative period was assessed and the efficacy of treatment using a popular non-opiate analgesic, magnesic metamizol, by the oral route was studied. In a period of six months 63 consecutive patients were operated on by the same surgeon using the same technique of hernia repair (Shouldice technique) with local infiltration anesthesia supplemented by MAC in the form of conscious sedation. A mixture of 300 mg of plain mepivacaine and 50 mg of plain bupivacaine was used for infiltration. A standard dose of fentanyl 0.10 mg and midazolam 2 mg was used for conscious sedation. Propofol in continuous infusion was also employed. The average dose of propofol varied from 1–3 mg/kg/h. Conscious level was assessed using a five-point sedation score. A level-3 end point was persued (closed eyes, but answer verbal orders). Pain intensity in the postoperative period was measured by the visual analogue scale (VAS) and the verbal pain scale (VPS), based on the McGill pain questionnaire. The operating conditions were excellent in all cases except in three patients. In no case conversion to general anesthesia was necessary. In the postoperative period, 5 patients (8%) never felt pain and 58 (92%) felt pain on the average 4 hours 36 minutes after the local infiltration (VAS=2.5; VPS=1.45). Of the 58 patients 49 took the first dose of oral analgesic 6 hours 40 minutes after infiltration (VAS=4; VPS=1.97). All patients were satisfied with the anesthetic-surgical technique and were ready to repeat the experience. However, when the patients took the second dose of oral analgesic 28% of them had moderate pain and 9% severe pain. Our conclusions are that local infiltration with MAC is a valid and satisfying experience for both the patient and the surgeon. Nevertheless, further attempts should be made to better the postoperative pain relief when the oral route is elected.