Topical anesthesia with eutetic mixture of local anesthetics cream in vasectomy: 2 randomized trials

Abstract

Two paired randomized trials testing topical anesthesia with a eutetic mixture of local anesthetics (EMLA cream*) in vasectomy were performed. In 1 trial EMLA cream was applied on 1 side of the scrotum, while infiltration anesthesia into the skin and subcutaneous tissue with mepivacaine was used on the contralateral side. All but 1 of the 13 patients (p less than 0.05) preferred infiltration anesthesia because of pain as the incision reached the subcutaneous tissue. In the other trial 29 patients received EMLA cream on 1 side of the scrotum before bilateral mepivacaine infiltration. There was significantly less pain on the sides with the anesthetic cream (p less than 0.001). Many patients would pay the price of the cream. In conclusion, EMLA cream cannot replace but it can supplement infiltration anesthesia during vasectomy.

PIP: 2 types of randomized trials of a topical melting cream containing a mixture of local anesthetics (EMLA cream) alone or with infiltration with mepivacaine are reported in men having vasectomy. A sequential trial design was used so that the trial could be stopped when statistical significance was reached. EMLA cream was applied to a 20 square cm area and covered with occlusive tape for 30 minutes preoperatively. In the 1st trial 13 men received EMLA cream on one side and mepivacaine on the other. 12 of 13 preferred infiltration because they experienced pain when the incision reached the subcutaneous tissue. Subjects rated the procedure with EMLA cream as more painful than the one on the contralateral side, and 4 stated that they would have preferred the cream before infiltration. The procedure took on average 2 minutes longer to allow for another mepivacaine injection. In the 2nd trial 29 men had either infiltration anesthesia or both. All 15 men who had both anesthetics preferred the combined anesthesia, and 14 of the 15 stated that they would be willing to pay out-of pocket for the cream.