Prevention of Ventricular Fibrillation After Aortic Declamping During Cardiac Surgery

Ventricular fibrillation is common after aortic declamping during cardiac surgery. Ventricular fibrillation and its treatment with countershock increases the myocardial injury. In order to evaluate the effects of lidocaine who were given intravenously, 200 mg lidocaine was given 3 minutes before aortic declamping to 20 patients who were selected as a study group. No medication was given before aortic declamping to 22 patients in the control group. Several baseline variables were similar in the two groups (clamp times, medications, the extent and type of surgery). Ventricular fibrillation occurred after aortic declamping in 5 of 20 patients in the study group and 17 of 22 patients in the control group (p<0.05). A mean of 1.64 countershock in the study group and mean of 1.64 countershock in the study group and mean 2.66 countershocks in the control group were necessary in cases with fibrillation (p<0.05). The serum potassium level also affected the incidence of ventricular fibrillation independently of lidocaine. Elevated serum potassium levels were associated with a lower incidence of ventricular fibrillation. Although lidocaine was independently protective at all potassium levels, the combination of lidocaine and a high serum potassium level had the greatest effect in preventing fibrillation.