Evaluation of Dexmedetomidine Dosing in Obese Critically Ill Patients

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.

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

BACKGROUND

Propofol and dexmedetomidine are routinely used in intensive care units (ICUs). Both are lipophilic, potentially leading to accumulation in adipose tissue. Limited evidence exists on what body weight to utilize in patients with morbid obesity.

OBJECTIVE

The purpose of this research was to evaluate the safety and efficacy of weight-based sedation with propofol and dexmedetomidine in ICU patients with morbid obesity.

METHODS

Retrospective review of ICU patients admitted from January 2018 to January 2020 who were sedated for ≥48 hours was performed. The primary outcome was the percentage of time within target sedation during the first 48 hours, stratified by body mass index (BMI) <40 or ≥40 kg/m². Additional outcomes included adverse events and the infusion rate to achieve target sedation. Data were evaluated using descriptive statistics.

RESULTS

A total of 80 patients were analyzed. Patients on propofol with a BMI <40 kg/m² were in their target Richmond Agitation-Sedation Scale (RASS) 11.7% versus 16.1% with a BMI ≥40 kg/m² (P = .580). Patients with a BMI <40 kg/m² on dexmedetomidine were in their target RASS 27.6% versus 10.7% with a BMI ≥40 kg/m² (P = .053).

CONCLUSION AND RELEVANCE

Body mass index did not significantly alter propofol target sedation attainment. However, patients with morbid obesity on dexmedetomidine demonstrated significantly less time in target sedation. An actual body weight dosing strategy of these drugs did not achieve desired target sedation for those with a BMI ≥40 versus BMI <40 kg/m². These findings support future research on the optimal sedation dosing strategy in this patient population.