Vignocaine Viscous Overdosage

The most serious effects of lignocaine intoxication are on the central nervous system (CNS) and cardiovascular system and overdosage can result in severe hypotension, asystole, bradycardia, apnoea, seizures, coma, cardiac arrest, respiratory arrest and death. Although the bioavailability of lignocaine is low it may be sufficient to result in significant toxicity when swallowed and there have been reports of CNS effects, seizures, and death in children and adults after the ingestion of topical solutions and after the use of viscous preparations in the mouth. Lignocaine is absorbed from mucous membranes and serious toxicity has been reported after urethral or rectal instillation of lignocaine preparations.
The first consideration is prevention, best achieved by careful and constant monitoring of cardiovascular and respiratory vital signs and the patient's state of consciousness after each local anaesthetic administration. Severe neurological symptoms such as convulsion and CNS depression must be treated symptomatically by administration of anti-convulsive drugs, respiratory support by maintenance of a patent airway and assisted ventilation with oxygen. Circulatory depression must be treated with supportive treatment which may require administration of intravenous fluids and, when appropriate, a vasopressor (e.g. ephedrine) as indicated by clinical situation. Immediate cardiopulmonary resuscitation should be instituted if circulatory arrest occurs.