Year : 2016

Volume : Volume 6

Issue : Issue 2

Address for correspondence :
Dr. Raghava P
raghava@gmail.com

Abstract

Background:  Since Heinrich Braun in 1904 conceived the use of epinephrine to enhance local anaesthesia, its use has dominated the surgery. Even though in subsequent years, nordefrin, phenylephrine, norepinephrine, and levonordefrin were developed as adrenergic vasoconstrictors, none of these agents has proved superior or perhaps even equal to epinephrine.  By opposing the vasodilating action of the local anesthetic, epinephrine retards its absorption from the injection site, thereby extending duration of action. Addition of a vasoconstrictor to a local anesthetic may have several beneficial effects: a decrease in the peak plasma concentration of the local anesthetic agent, increase in the duration and the quality of anesthesia, reduction of the minimum concentration of anesthetic needed for nerve block, and decrease of blood loss during surgical procedures. Local anaesthetics containing epinephrine have been considered relatively safe pharmacological agents and have been used in dental practice for over fifty years. However, like all pharmacological agents epinephrine added to the local anaesthetics can also exert its own action on the recipient site and its absorption into the circulation has a potential to causes systemic effects. The discussion regarding the safety of epinephrine in local anaesthetics, its effect on the body and its physiology has been a topic of debate and contention for a very long time. There have been a range of issues about the effects of epinephrine like, its effects on central nervous system, use in cardiac patients, effects on endocrine system, use in extremities and possible drug interactions with inhalational anesthetics, tricyclic antidepressants, beta blockers and, possibly, phenothiazines. This concern can be well founded and is because the amounts of epinephrine used in dentistry can result in significant elevations in circulating levels of epinephrine and concomitant physiologic changes. So, it can be contended that addition of a vasoconstrictor to a local anesthetic does have a potential to also have some detrimental effects. Review of the current available literature suggests that eliciting a thorough medical history of the patient, use of minimum required concentrations of epinephrine in local anaesthetics, avoiding an intravascular injection as some of the ways to avoid any untoward systemic effects.

Keywords: Local anesthesia, epinephrine, systemic effects, dogmas and facts.