Epinephrine Prolongs Duration of Subcutaneous Infiltration of Local Anesthesia in a Dose-related Manner:: Correlation With Magnitude of Vasoconstriction

Abstract

Epinephrine prolongs duration of analgesia after local infiltration in a dose-related manner. Addition of epinephrine in concentrations of 1:50,000 or 1:200,000 increases duration of analgesia after local infiltration by approximately 200%. Addition of doses as dilute as 1:3,200,000 still increases duration of analgesia by approximately 100%. Duration of analgesia appears to correlate with magnitude of epinephrine-induced vasoconstriction using laser Doppler flowmetry. Based on study data, the use of epinephrine in concentrations from 1:200,000 to 1:3,200,000 is recommended for prolongation of analgesia after local infiltration.