Evaluation of Dexmedetomidine Dosing in Obese Critically Ill Patients

Abstract

Background: Dexmedetomidine is a highly selective α2-adrenoreceptor agonist that produces dose-dependent sedation, anxiolysis, and analgesia without respiratory depression. Due to these ideal sedative properties, there has been increased interest in utilizing dexmedetomidine as a first-line sedative for critically ill patients requiring light sedation. Objective: To evaluate the ability to achieve goal intensive care unit (ICU) sedation before and after an institutional change of dosing from actual (ABW) to adjusted (AdjBW) body weight in obese patients on dexmedetomidine. Methods: This study included patients ≥ 18 years old, admitted to a surgical or medical ICU, required dexmedetomidine for at least 8 hours as a single continuous infusion sedative, and weighed ≥ 120% of ideal body weight. Percentage of RASS measurements within goal range (−1 to +1) during the first 48 hours after initiation of dexmedetomidine as the sole sedative agent or until discontinuation dosed on ABW compared to AdjBW was evaluated. Results: 100 patients were included in the ABW cohort and 100 in the AdjBW cohort. The median dosing weight was significantly higher in the ABW group (95.9 [78.9-119.5] vs 82.2 [72.1-89.8] kg; p = 0.001). There was no statistical difference in percent of RASS measurements in goal range (61.5% vs 69.6%, p = 0.267) in patients that received dexmedetomidine dosed based on ABW versus AdjBW. Conclusion: Dosing dexmedetomidine using AdjBW in obese critically ill patients for ongoing ICU sedation resulted in no statistical difference in the percent of RASS measurements within goal when compared to ABW dosing. Further studies are warranted.

Adherence to Sedation Targets With Weight-Based Propofol and Dexmedetomidine in Patients With Morbid Obesity

“…Interestingly, a recent study demonstrated no statistical difference in sedation compliance when dexmedetomidine was dosed using ABW versus AdjBW. 8 However, it is our assumption that dosing dexmedetomidine based on AdjBW may lead to decreased adverse events and cost, while maintaining appropriate sedation outcomes. A similar recommendation is presented in a recent meta-analysis of sedation and analgesia in critically ill patients with obesity.…”

“…7 Despite more recent studies in patients with ≥120% of their ideal body weight showing no difference in sedation compliance when dosing dexmedetomidine on actual body weight (ABW) versus adjusted body weight (AdjBW), AdjBW dosing may reduce cost and minimize overall sedation exposure. 8 Based on previous literature, it is still unclear how to effectively and to safely sedate critically ill patients with morbid obesity, especially within the first 48 hours of initiation, when most dose finding occurs. Our institution currently uses ABW to dose continuous infusions of propofol and dexmedetomidine.…”

“…7 Despite more recent studies in patients with ≥120% of their ideal body weight showing no difference in sedation compliance when dosing dexmedetomidine on actual body weight (ABW) versus adjusted body weight (AdjBW), AdjBW dosing may reduce cost and minimize overall sedation exposure. 8…”

Evaluation of Dexmedetomidine’s Effect on Temperature in Obese Critically Ill Patients

“…A single center, retrospective, post hoc analysis was conducted using body temperature data collected from participants from our previously published study evaluating dexmedetomidine dosing in obese critically ill patients for ongoing ICU sedation. 15 Patients were identified through the information warehouse by running a report for all patients who received dexmedetomidine within the study timeframe. Records were analyzed until the pre-specified sample size was achieved for our previous study.…”

“…Records were analyzed until the pre-specified sample size was achieved for our previous study. 15 All potential patients for screening during the study timeframe were randomized and then screened until the total desired sample size was attained. All patients were initiated, per protocol, on a dexmedetomidine infusion at an initial rate of .2-.4 mcg/kg/hr and titrated by .1-.2 mcg/kg/hr increments no more frequently than every 30 minutes to achieve a goal RASS of 1 to -1.…”