Lidocaine in out-of-hospital ventricular fibrillation. Does it improve survival?

BACKGROUND: A large proportion of cardiac arrests outside hospital are caused by ventricular fibrillation. Although it is frequently used, the exact role for treatment with lidocaine in these patients remains to be determined.

AIM: To describe the proportion of patients with witnessed out-of-hospital cardiac arrest found in ventricular fibrillation who survived and were discharged from hospital in relation to whether they were treated with lidocaine prior to hospital admission.

PATIENTS AND TREATMENT: All the patients with out-of-hospital cardiac arrest found in ventricular fibrillation in Göteborg between 1980 and 1992 in whom cardiopulmonary resuscitation (CPR) was initiated by our emergency medical service (EMS). During the observation period, some of the EMS staff were authorized to give medication and some were not.

RESULTS: In all, 1,360 patients were found in ventricular fibrillation, with detailed information being available in 1,212 cases (89%). Lidocaine was given in 405 of these cases (33%). Among patients with sustained ventricular fibrillation, those who received lidocaine had a return of spontaneous circulation (ROSC) more frequently (P < 0.001) and were hospitalized alive more frequently (38% vs. 18%, P < 0.01). However, the rate of discharge from hospital did not significantly differ between the two groups. Among patients who were converted to a pulse-generating rhythm, those who received lidocaine on that indication were more frequently alive than those who did not receive such treatment (94% vs. 84%; P < 0.05). However, the rate of discharge did not significantly differ between the two groups.

CONCLUSION: In a retrospective analysis comparing patients who received lidocaine with those who did not in sustained ventricular fibrillation and after conversion to a pulse-generating rhythm, such treatment was associated with a higher rate at ROSC and hospitalization but was not associated with an increased rate of discharge from hospital.