Retrospective evaluation of dexmedetomidine dosing in a cohort of neurologically injured obese critically ill patients

BACKGROUND: Dexmedetomidine is used in neurocritical care units (NCCUs) due to the light, dose-dependent sedation, and anxiolysis provided. It is unknown how to dose dexmedetomidine in obese patients. The primary objective is to assess the ability to achieve the goal Richmond Agitation Sedation Scale (RASS) measurements in obese patients with a neurological injury who are solely on dexmedetomidine before and after an institutional dosing change from actual body weight (ABW) to adjusted body weight (AdjBW). METHODS: This study included patients admitted to the NCCU with a neurological condition, required dexmedetomidine for at least 8 h as a sole sedative, and weighed ≥120% of ideal body weight. Percentage of RASS measurements within the goal range (−1 to +1) during the first 48 h while on dexmedetomidine were compared between patients dosed on ABW and on AdjBW. RESULTS: Sixty-eight patients in the ABW cohort and 72 patients in the AdjBW cohort were included. There were no statistical differences between the two groups (ABW vs. AdjBW) in the percent of RASS measurements in the goal range (53.2% ± 34.8% vs. 55% ± 37%; P = 0.78), mean weight (99.2 ± 26 vs. 96.8 ± 20.9 kg; P = 0.55), or the average dose of dexmedetomidine required to achieve first goal RASS score (0.4 ± 0.3 vs. 0.4 ± 0.3 mcg/kg/h; P = 0.98). CONCLUSIONS: Dosing dexmedetomidine using AdjBW in obese critically ill neurologically injured patients for ongoing sedation resulted in no statistical difference in the percent of RASS measurements within the goal when compared to ABW dosing. Further studies are warranted.