The effect of meperidine on lidocaine-induced axillary block in patients undergoing upper extremities surgery

Background: The increasing use of regional anesthesia and peripheral nervous blocks and also local anesthetic effects of meperidine, made us adding this drug to lidocaine-induced axillary block for patients undergoing upper extremities surgery to measure its effects and especially block length time. Objective: The aim of this study is effect survey of meperidine on lidocaine-induced axillary block in patients undergoing upper extremities surgery. Materials and Methods: This randomized double-blinded clinical trial was conducted on consecutive forty patients aged between 15 and 56 years, rated as the American Society of Anesthesiology I-II who were scheduled for upper extremities surgery. The study protocol was approved by the ethics committee at Kermanshah University of Medical Sciences. These 40 patients divided into two groups which were similar in terms of age, gender, and weight. The patients were randomly assigned to receive one of the two following protocols for axillary block: (1) 40 ml lidocaine 1% plus 0.01 ml/kg normal saline and (2) 40 ml lidocaine 1% plus 0.01 ml/kg equaling 1 mg/kg meperidine. The blocking method was similar in both groups (Ultrasound-Guided Axillary block). The analysis was done with Chi-square and Fisher's exact test for complications and t-test for quantitative variables in both groups. Results: Both two groups were similar in terms of block onset time, the intensity of analgesia block and side effects such as nausea, vomiting, hypotension, dizziness, arrhythmia, and convulsion. The obtained results from this study suggest that meperidine added to lidocaine-induced axillary block prolongs the duration of blocked (238 ± 67.04 vs. 166.7 ± 39.6) which is statistically significant (P < 0.001). Conclusion: According to the study findings, the axillary block onset time was not statistically different between two groups. Totally adding meperidine to lidocaine-induced axillary block did not lead to increase the systemic side effects, but prolonged duration of blockade significantly. It is suggested to use this method for prolonged surgeries especially in emergency patients with contraindication for general anesthesia and also for general populations who have short time upper extremity surgery and also to provide a long-term postoperation analgesia.