Continuous Infusion versus Intermittent Bolus Dosing of Vecuronium in Patients Receiving Therapeutic Hypothermia After Sudden Cardiac Arrest

Abstract

To compare the effects of vecuronium administered as an intravenous continuous infusion versus intermittent bolus doses in patients treated with therapeutic hypothermia after sudden cardiac arrest (SCA). Design. Retrospective medical record review. Cardiac care unit of a university-affiliated, level I trauma center. Of 123 adults treated with therapeutic hypothermia after SCA, 80 received continuous-infusion vecuronium 0.8 μg/kg/minute started 2 hours after cooling began or if shivering occurred (January 1, 2004-December 31, 2007), and 43 received intermittent boluses of vecuronium 0.05 mg/kg every 2 hours (January 1, 2008-September 30, 2009). The degree of neuromuscular blockade was measured with a train-of-four (TOF) test. Primary outcomes evaluated were time to achieve goal TOF response and percentage of time the TOF response was maintained at goal. Secondary outcomes included total daily dose of vecuronium, the vecuronium dose needed to achieve goal TOF response, percentage of TOF measurements above or below goal, and time to return of spontaneous respirations and time to extubation after the last dose of vecuronium. The goal TOF response was achieved significantly earlier in the bolus group than the continuous-infusion group (mean 5.9 vs 11.3 hrs, p=0.008). The mean total daily dose of vecuronium administered in the bolus group was significantly lower than that in the continuous-infusion group (51.7 vs 76.9 mg, p=0.002). The mean percentage of TOF measurements above goal was higher in the continuous-infusion group (33% vs 16%, p<0.0001), and the mean percentage of TOF measurements below goal was higher in the bolus group (43% vs 29%, p<0.0001). The median time to return of spontaneous respirations (6 vs 11 hrs, p=0.017) and time to extubation (29.5 vs 89.5 hrs, p<0.0001) were significantly shorter in the continuous-infusion group than the bolus group. Intermittent boluses of vecuronium were more effective in reaching a goal TOF response earlier compared with continuous-infusion vecuronium in patients treated with therapeutic hypothermia. The two dosing strategies were equally effective at maintaining a goal TOF response despite patients receiving a significantly lower daily dose of vecuronium in the intermittent-bolus group.