Experimental Study of Tumescence Injection to Provide Anesthesia Without Local Anesthetics

Background: One-per-mil tumescent technique could provide local anesthesia in surgical procedures despite using low lidocaine concentration. Tumescence environment within the tissue may play a role in supporting local anesthesia effect. This study aims to delineate whether the tumescence environment, created by one-per-mil solution without a local anesthetic agent, had a local anesthesia effect. Methods: Four different compositions and volumes of tumescent solutions containing 1:1,000,000 epinephrine were injected into 50 Swiss Webster mice. The animals were divided into five groups: group A, a tumescent solution with 0.2% lidocaine; group B, a tumescent solution with 0.04% lidocaine; group C, a tumescent solution without lidocaine; group D, a doubled volume of tumescent solution without lidocaine; and group E, controls. Local anesthesia effects were tested by using the formalin test (n = 25) and tail immersion test (n = 25). Pain response behavior in the form of paw licking duration and tail withdrawal latency was observed. The analysis of variance and Kruskal-Wallis tests were used to test the statistical difference. Significance was set at P < 0.05. Results: The four interventional groups showed less pain response behavior and significantly longer tail withdrawal latency (P < 0.05) than the control group. However, the groups showed nonsignificantly shorter paw licking duration than the control (P > 0.05). Group A had the fastest onset of the local anesthesia effect. Conclusions: The tumescence environment was potentially able to provide a local anesthesia effect, although the solution did not contain a local anesthetic agent as proved by the tail immersion test.