# Deciphering the Enigma: Lignocaine Resistance After Scorpion Envenomation

## TL;DR

A patient with a history of a scorpion bite showed resistance to lignocaine, and alternative anesthetics like ropivacaine were found to be effective.

## Contribution

This case report highlights lignocaine resistance linked to scorpion envenomation and suggests alternative anesthetics for such patients.

## Key findings

- The patient exhibited resistance to lignocaine due to scorpion envenomation 18 years prior.
- Ropivacaine was effective as an alternative local anesthetic for airway management and surgery.
- Scorpion venom may modify sodium channels and affect local anesthetic efficacy.

## Abstract

Lignocaine, an amide-type local anesthetic (LA), is routinely used in dentistry. Resistance to lignocaine is rare, and it can occur due to various reasons, such as genetic mutations or variations in the local environment where it is injected. One reason might be scorpion envenomation.

We report a case of a 39-year-old female patient with a chief complaint of a gradual reduction in mouth opening for the past five years, with a history of scorpion bite. The patient had a scorpion bite 18 years back. She started developing symptoms of oral submucous fibrosis five years ago. The patient exhibited resistance to lignocaine, after which alternate agents were tried. We found that ropivacaine was effective as a LA, enabling airway management via cricothyrotomy and subsequent nasal intubation, following which bilateral fibrotomy, bilateral coronoidectomy, and bilateral nasolabial flap reconstruction were performed.

The resistance to lignocaine is due to modifications in the sodium channels. Scorpion venom affects the local environment surrounding the nerve and has systemic effects as well. As an alternative to lignocaine, bupivacaine and ropivacaine can be tested for sensitivity.

In patients with a recent history of scorpion bites, there is a higher chance of resistance to lignocaine. Therefore, evaluating the patients with a history of scorpion bites for resistance to lignocaine before any procedure is mandatory.