Efficacy of 2% lignocaine medicated pad for pain alleviation during rabies immunoglobulin administration: A randomized controlled trial

Background: Rabies immunoglobulin (RIG) for animal bite victims is usually administered around the wound without the use of any anesthetic. Theoretically, the topical use of 2% lignocaine can reduce the pain during the procedure. Objectives: This study aimed to determine the efficacy of 2% lignocaine medicated pad (LMP) for reducing pain during administration of RIG. Methods: A randomized triple-blind controlled trial was done in a tertiary care setting in Kerala, India. The proximal and distal wounds of the patient with minimum two, Category III animal bite wounds were randomized to intervention and placebo arms, based on a previously generated random number sequence. Sterile gauze pads soaked with 2% lignocaine and normal saline were the intervention and placebo, respectively. Pain was the primary outcome measure and was assessed using numeric rating scale (NRS) and sound, eye, and motor pain (SEM) scale. The patient, outcome assessor, and statistician were blinded. Results: The wound sites and size of 100 intervention and 100 control wounds were comparable. The score of all elements of the SEM, total SEM, and NRS score were significantly lower in the wounds, which were given LMP compared to the control wounds. The number needed to treat for satisfactory pain relief and immediate pain relief was 25 and 14, respectively. No serious or minor adverse events were reported in the trial. Conclusions: The use of a proven drug in a topical route optimizes pain reduction from iatrogenic cause for millions of animal bite victims around the world with very little additional financial burden.