Influence of Hyaluronidase Upon Local Infiltration Anaesthesia by Lidocaine: An Experimental Study in the Guinea-pig

Abstract

A study was made in the guinea-pig to examine how the mucolytic enzyme hyaluronidase influenced the spread and duration of subcuianeously injected lidocaine with and without adrenaline. Addition of hyaluronidase 200 IU/ml to lidocaine 5 mg/ml plain solution diminished the spread of the analgesic efficacy but did not affect the duration of action. Addition of hyaluronidase 200 IU/ml to lidocaine 5 mg/ml containing adrenaline 5 ug/ml gave a significantly larger area of analgesia compared to the solution without the enzyme but slightly shortened the duration of action. The solution containing both adrenaline and hyauronidase approximately doubled the distance necessary for satisfactory analgesia between two subcutaneous sites of administration, a finding that may have clinical implications.