The ed-sed multicenter study of outcomes associated with sedation depth for mechanically ventilated patients

Background: A previous investigation of mechanically ventilated patients demonstrated that deep sedation in the ED was common (64%), and associated with increased mortality, longer ventilation duration, and longer lengths of stay. As this was a single center study, it is unknown if the results are generalizable. The objective of this study was to test the hypothesis that deep sedation in the ED is associated with worse clinical outcomes in mechanically ventilated patients. Methods: This was a multicenter, prospective cohort study which enrolled 271 mechanically ventilated ED patients at fifteen academic medical centers during a one-month time frame. Deep sedation was defined as a Richmond Agitation-Sedation Scale of-3 to-5 or Sedation Agitation Scale of 2 or 1. Outcomes of interest included ventilator-free days, lengths of stay, mortality, and acute brain dysfunction (delirium and coma). The primary analysis examined ventilator-free days as a function of ED sedation depth. A multivariable linear regression model was constructed to adjust for potentially confounding variables using backward elimination. Results: ED deep sedation was observed in 143 patients (52.8%), and was associated with a higher incidence of deep sedation in the ICU on day one (53.1% vs. 21.1%, p= 0.003), when compared to light sedation. Mean (SD) ventilator-free days were 17.7 (11.1) in the ED deep sedation group compared to 19.4 (10.1) in the light sedation group (mean difference 1.7; 95% CI-0.90 to 4.22, p= 0.20). Similar results according to ED sedation depth existed for ICU-free days (mean difference 1.5; 95% CI-0.88 to 4.20, p= 0.27) and hospital-free days (mean difference 2.2; 95% CI-0.01 to 4.42, p= 0.051). Mortality was 21.7% in the deep sedation group and 16.4% in the light sedation group (between-group difference 5.3%; OR 1.41; 0.76-2.61, p= 0.27). The incidence of acute brain dysfunction was 65.7% in the deep sedation group and 53.1% in the light sedation group (between-group difference 12.6%; OR 1.69; 1.04-2.76, p= 0.04). Conclusion: Early deep sedation in the ED is common in mechanically ventilated patients, carries over into the ICU, and may be associated with worse outcomes. Sedation practices in the ED and associated clinical outcomes are in need of further investigation