Subcutaneous Injection of Large Volumes of Tumescent Lidocaine and Epinephrine by Laypersons

Overview

This research is intended to show that it is safe and not difficult for nearly anyone to inject at least 125ml of a dilute solution of tumescent lidocaine and epinephrine (TLE), where a TLE solution consists of lidocaine (1gm/L) and epinephrine (1mg/L) in normal saline.

The primary aim of this research is to demonstrate that of subcutaneous injection of tumescent (dilute) lidocaine and epinephrine (TLE) is safe, well tolerated, and easily performed by nearly anyone who is at least 16 years old. The primary aim will be achieved by conducting an IRB-approved double-blind, non-inferiority, randomized clinical trial (RCT). The indications for TLE when injected into subcutaneous tissue are * Pre-hospital treatment of a snakebite envenomation (SBE) * Dermatologic surgical procedures totally by local anesthesia * Pure sensory regional anesthesia for significant cutaneous and musculoskeletal pain. The present TLE-RCT has three research Arms, which are as follows: Injection of 125ml by a physician and self-injection of 125ml by a volunteer (Arm I): A volunteer layperson (research subject), at least 16 years of age, will first receive 125ml of TLE injected subcutaneously into the left anterior thigh by a physician. Then the subject will self-inject a second 125ml of TLE into his/her right anterior thigh. Injection of 125ml by a physician and 125ml by another volunteer (Arm II): A volunteer layperson (primary research subject), at least 16 years of age, will first receive 125ml of TLE injected subcutaneously into the left anterior thigh by a physician. The primary research subject will then receive a second 125ml of TLE injected into his/her right anterior thigh by a second adult volunteer who is at least 16 years old and not a medical professional. Injection of 250ml by a physician into a volunteer (Arm III) : A volunteer layperson (research subject), at least 16 years of age, will receive 250ml of TLE injected subcutaneously into the one anterior thigh by a physician. There will be two TLE formulations, F1 and F2. * F1 contains epinephrine 1mg/L = 1:1,000,000, or 0.25mg/250ml. * F2 contains epinephrine 2mg/L = 1:500,000, or 0.5mg/250ml. F1 and F2 will both contain lidocaine 1gm/L = 0.1gm/100ml = 0.1% The maximum dose of dilute tumescent epinephrine in F1 and F2 is 0.25mg and 0.5mg, respectively. An EpiPen® contains 0.3mg of epinephrine. The concentration of epinephrine in an EpiPen® is 1:1000, which is 1000 and 500 times greater than the concentration of epinephrine in F1 and F2, respectively. Individual subjects will be randomly assigned to receive either F1 or F2. The maximum dosage of tumescent lidocaine is 5mg/kg, which is clearly a safe dosage given that the risk of mild lidocaine toxicity at 28mg/kg of 0.1% TLE is 1 per 5,000,000