959

Abstract

Introduction: Prior studies have examined heart rate and cardiovascular effects in the setting of a loading dose followed by short term infusions of dexmedetomidine in adults and in children. We sought to describe the cardiac effects in critically ill children related to continuous infusion of dexmedetomidine without a loading dose for up to 24 hours of infusion. Hypothesis: Continuous infusion of dexmedetomidine without a loading dose will have minimal cardiac effects. Methods: Hemodynamically stable intubated patients in the pediatric critical care unit were infused at a rate of 0.7ug/kg/hour of dexmedetomidine for sedation prior to anticipated extubation attempt within 24 hours. Patients received a minimum of 6 hours of infusion of drug. Cardiovascular effects were monitored up to 24 hours or until infusion discontinuation. EKG was monitored continuously and HR, SBP, DBP, MAP, RR, and O2 sat were recorded at baseline, at 5, 10, 15, 25, 35, 45, 55, and 65 mins and then hourly thereafter up to 24 hours. Patients were predetermined to exit from study by predetermined HR and BPs set-points <5% for age. Changes in hemodynamic variables were compared to baseline by paired t-test and repeated measures ANOVA analysis. Results: A total of 17 intubated patients, mean age of 3yrs, (range 0.25 -17 yrs), mean weight 20kg (range 2.8-84kg) received a dexmedetomidine infusion for a mean of 16 hours (range 6 to 24 hours). There were no conduction abnormalities. 1 patient required discontinuation of infusion for predetermined low HR limits at hour 13 (baseline HR 64, discontinued at HR 57) coinciding with planned extubation. Mean HR decreased by 9 bpm at 65 mins (p<0.05) but HR changes were not statistically significant at any other time frame. Similarly, there was no significant change in SBP, MAP and DBP during the observed time periods. Conclusions: Significant cardiovascular side effects were not noted in continuous sedation of dexmedetomidine without a loading dose in critically ill children for infusions up to 24 hours. Consideration to withhold a loading dose may result in more patient tolerability and provider comfort with managing infusions.