Comparison of buffered and unbuffered local anaesthesia for inguinal hernia repair: a prospective study

Bicarbonate buffered local anaesthetic solutions are known to reduce the pain of infiltration. However, its efficacy in reducing the pain of infiltration in patients undergoing inguinal hernia repair has never been tested. This study aims to test the efficacy of bicarbonate buffered solution in reducing the pain of infiltration and pain for the total surgical procedure in a series of patients undergoing elective inguinal hernia repair. Forty consecutive male patients with unilateral, reducible inguinal hernias were studied prospectively. All patients underwent surgery under local anaesthesia, the first 20 with unbuffered solution and the next 20 using buffered solution. Pain scores were obtained for the infiltration in the anaesthetic room and for the total surgical procedure. In addition, satisfaction scores were obtained at the end of the procedure. The mean pain score for the initial infiltration of unbuffered anaesthetic was 3.00 (range 0-5), and for the buffered anaesthetic it was 1.45 (range 0-4), P=0.02. The mean pain score for the entire procedure for the unbuffered group was 3.05 (range 0-6), and for the buffered group it was 1.45 (range 0-5), P=0.02. The patient satisfaction rate was higher with the buffered solution compared to unbuffered solution (P<0.05). There were no complications reported with either solution. Buffered local anaesthetic solution significantly reduces the perceived pain of inguinal hernia repair, both during the infiltration and during the procedure itself. It is safe to administer and it results in a high rate of patient satisfaction.