Predictors of a Response to Dexmedetomidine in Intubated, Critically Ill Adult Patients

BACKGROUND Dexmedetomidine is a centrally acting α-2 receptor agonist used to maintain light analgosedation in mechanically ventilated adults. This study was conducted to determine factors predictive of successful maintenance of light sedation (Richmond Agitation-Sedation Scale (RASS) 0 to -2) for ≥60% of the first 48 h of mechanical ventilation with dexmedetomidine. METHODS This was a single-center, retrospective, cohort study of critically ill adult patients receiving dexmedetomidine and admitted to an intensive care unit (ICU) between January 1, 2013, and August 31, 2019. A multivariable logistic regression analysis was performed in patients receiving dexmedetomidine for sedation to assess patient and clinical characteristics associated with a positive clinical response to dexmedetomidine. RESULTS Of 1065 patients reviewed for study inclusion, 158 patients were included. Sixty-two percent of patients initiated on dexmedetomidine to maintain light sedation were able to remain within this sedation target ≥60% of the time during the first 48 hours of therapy. Patients maintained within the target RASS score ≥60% of the time had a higher percentage of ventilator-free days at 14 days (p = 0.044). The odds of having a mean time within goal RASS score ≥60% in the first 48 hours of mechanical ventilation after intubation were decreased by 9% for every point increase in sequential organ failure assessment score (odds ratio: 0.91, 95% confidence interval: 0.82-0.99). CONCLUSION Patients were less likely to maintain light sedation with dexmedetomidine as their degree of critical illness increased. The duration of time maintained within goal sedation after dexmedetomidine initiation and the impact on patient outcomes remain a research priority.