Evaluating effective dose of dexmedetomidine: onset time of drug is critical

Loading dose of Dexdor® and optimal sedation during oral and maxillofacial ambulatory surgery procedures: An observational study

INTRODUCTION

Dexdor^® do not include the possibility of loading dose, which could increase time to achieve adequate sedation for ambulatory procedures. The objective of this study was to evaluate the effect of several loading dose of dexmedetomidine in the time to achieve and maintain an optimal level of sedation and its clinical hemodynamic repercussion.

MATERIAL AND METHODS

The IRB approved this observational study for patients that underwent oral and maxillofacial ambulatory surgery under dexmedetomidine at the University of Navarra Clinic from February 2013 to November 2014. According to the loading dose the patients were grouped into 3 categories:<0.5, 0.5, and>0.5μg/kg. Optimal level of sedation was defined as bispectral index<85. Data were analyzed using survival analysis techniques. Vasoactive drugs requirements was evaluated using exact logistic regression.

RESULTS

Eighty-one patients were evaluated. Hazard ratios for patients in 0.5 and >0.5μg/kg loading dose categories for achieving a bispectral index<85 were 1.5 (95% CI 0.9, 2.6) and 1.8 (95% CI 0.8, 3.9), respectively, compared with the lowest category. Five patients (6.2%) required atropine for bradycardia. Patients in the group>0.5μg/kg showed greater risk of requiring atropine compared with the group<0.5μg/kg (odds ratio 2.2; 95% CI 0.03, 183).

CONCLUSION

Loading dose of dexmedetomidine>0.5μg/kg appears minimize the time to achieve and maintain an optimal level of sedation during the first 60min of procedure. Further investigation to elucidate the association between loading dose of dexmedetomidine and subsequent atropine requirements may be warranted.