Atrioventricular block lidocaine

High-grade atrioventricular block has been reported in a 14-day-old infant who was given lidocaine 2 mg/kg intravenously (SED-12, 255) (16). 

Complete atrioventricular block occurred in a 10-year-old child with a history of hypertension, severe renal dysfunction, incomplete right bundle branch block, and a ventricular septal defect that had been repaired at birth (10). After slow induction with sevoflurane and nitrous oxide 66%, complete atrioventricular block occurred when the inspired sevoflurane concentration was 3% and reverted to sinus rhythm after withdrawal of the sevoflurane. The dysrhjrthmia recurred at the end of the procedure, possibly caused by lidocaine, which had infiltrated into the abdominal wound, and again at 24 hours in association with congestive cardiac failure following absorption of peritoneal dialysis fluid. 

Side effects should be monitored after the initiation of lidocaine. The most common adverse reactions are drowsiness, dizziness, paresthesia, and euphoria. Patients also may experience serious central nervous system (CNS) side effects such as confusion, agitation, psychosis, seizures, and coma, but usually only at supratherapeutic levels. The active metabolites of lidocaine are responsible for most of the CNS toxicities. Cardiovascular side effects, including atrioventricular block, hypotension, and circulatory collapse, are not as well correlated to lidocaine levels. 

One case of anaphylactic shock (27 ) and one of generalized exfoliative dermatitis (28 ) after the use of lidocaine as a local anaesthetic have been described. The intravenous administration of lidocaine in patients with myocardial infarction sometimes also leads to undesirable side effects, of which hypotension is the best known. The problem is mainly one for the cardiologist, but since inadvertent intravenous injection during local anaesthesia may occur, the anaesthetist must be aware of it. A case of sinusbradycar-dia after a bolus injection of 50 mg (29 -) and an atrioventricular block after 800 mg, given in the course of 12 hours (30 ) have been described. Two fatalities, one due to ventricular fibrillation after 50 mg and one to sinus arrest after 100 mg, have been re-... 

Lidocaine, proprietary name Xyhcaine, is the drug of choice for the initial therapy of PVCs and the prevention of ventricular arrhythmias. Lidocaine is contraindicated when bradycardias and severe atrioventricular node block appear after myocardial infarction. Lidocaine shortens the action potential refractory period in these fibers and does so at concentrations less than those required to exert pharmacological effects at other sites, such as the ventricular myocardium. 

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