Intermittent bolus dosing of lidocaine in emergency medical services - An alternative to bolus followed by a drip

Objective. To determine the effectiveness and safety, in an emergency medical services setting, of intermittent bolus dosing of lidocaine versus a bolus followed by a drip. Methods. This was a prechange and postchange observational study, following a protocol change. Patients 18 years or older treated with lidocaine for cardiac dysrhythmia were included in the study. Patients were excluded for lidocaine for intubation, cardiac arrest without return of spontaneous circulation, trauma, interhospital transport, and incomplete charts. Patients were divided into two groups. The drip group (January 1, 2002, to January 14, 2003) was treated with lidocaine 1.0-1.5 mg/kg intravenous bolus up to 3 mg/kg until the dysrhythmia resolved and then a 2-4 mg/min drip. The bolus group (January 15, 2003 to December 31, 2003) was treated with lidocaine 1.5 mg/kg intravenous bolus, followed by 0.75 mg/kg bolus every five minutes up to 3 mg/kg until the dysrhythmia resolved; once the dysrhythmia resolved, intermittent boluses of 0.75 mg/kg every 10 minutes were adminstered. Outcome variables studied were maintenance of rhythm of nonventricular origin, occurrence of complications, and adherence to written protocols. Complications considered were seizures, respiratory depression, and cardiac arrest. Results. The study included 146 patients in the drip group and 113 patients in the bolus group. Overall, 119 of 146 patients (81.5%) in the drip group and 101 of 113 patients (89.3%) in the bolus group maintained a rhythm of nonventricular origin (p = 0.079). There was no statistical difference between the two groups in complications or protocol variance: one of 146 patients (0.7%) in the drip group and one of 113 patients (0.9%) in the bolus group had a serious complication; 64 of 146 patients (43.8%) in the drip group and 54 of 113 patients (47.8%) in the bolus group had a protocol variance. Conclusions. Intermittent bolus dosing protocol was associated with an equivalent effectiveness in maintaining rhythms of nonventricular origin without an increase in complications.