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Continuous Infusion versus Intermittent Bolus Dosing of Vecuronium in Patients Receiving Therapeutic Hypothermia after Sudden Cardiac Arrest
Jurado LV, Gulbis BE. Pharmacotherapy 2011;31(12):1250-6
Study Question: Is there a difference in time to achieve goal train-of-four (TOF) or time maintained at goal TOF when giving vecuronium as intermittent boluses versus a continuous infusion to control shivering during therapeutic hypothermia?
Study Description: Retrospective, single-center, medical record review of patients treated with hypothermia after sudden cardiac arrest (SCA) who were 18 yrs or older and received at least one dose of vecuronium. Patients were excluded if they did not have TOF documentation or if they died within 12 hours of initiation of therapeutic hypothermia. Patients were divided into two cohorts: vecuronium continuous infusion and vecuronium bolus. The infusion was administered at 0.08 mcg/kg/min and titrated to TOF 1/4-2/4. The boluses were administered as 0.5 mg/kg q 1 hour prn shivering while in ED and cardiac catheterization lab, then 0.5 mg/kg q 2 hours as needed to achieve TOF 1/4-2/4. TOF responses were assessed and documented hourly. The primary outcomes were time to achieve goal TOF response and percentage of time the TOF response was maintained at goal.
Results: There were a total of 123 patients included, 83 in the continuous infusion group and 43 in the bolus group. The bolus group achieved TOF goal 5.4 hrs earlier than the infusion group (5.9 vs. 11.3 hrs, p=0.008). There was no significant difference in the percentage of TOF at goal (40.3 vs. 35.4%, p=0.34). The total daily dose of vecuronium in the bolus group was lower than in the infusion group (p=0.002). However, the percentage of TOF measurements above goal (under-paralysis) was higher in the infusion group and the percentage of TOF measurements below goal (over-paralysis) was higher in the bolus group. The time to return of spontaneous respirations and time to extubation were shorter in the infusion group, 6 vs. 11 hrs (p=0.0175) and 29.5 vs. 89.5 hrs (p<0.0001), respectively.
Conclusion(s): Administration of vecuronium as intermittent boluses was more effective in reaching a goal TOF response earlier than administration by continuous infusion; however, the two dosing strategies are equally effective at maintaining a goal TOF response.
Perspective: Although bolus administration reduced total drug administered and reached goal TOF faster, the time to return of respirations and time to extubation were longer in the bolus group. Interestingly, under-paralysis was more common in the infusion group and over-paralysis was more common in the bolus group. Based on this study bolus administration can be an option for these patients but more studies are needed to determine which administration method is superior.