Associations of Emergency Department Sedation and Analgesia and Hospital Outcomes in Mechanically Ventilated Patients

Objective: Deep sedation has been hypothesized to be harmful in mechanically ventilated patients in the Emergency Department (ED). This study investigated the relationship between the level of sedation, immediately following ED intubation and within 24 hours of ICU admission, and hospital mortality.

Design: Retrospective cohort

Setting: Single center in Northeastern United States between January 1, 2016, and December 31, 2017

Patients: From the National Emergency Airway Registry of adult patients presenting to the ED, 294 patients underwent intubation and received mechanical ventilation. Patients who were intubated at a referring hospital, died in the ED, or required chronic mechanical ventilation prior to presentation were excluded. 

Measurements and Main Results: Patients were classified as receiving deep or light sedation based upon the Richmond Agitation-Sedation Scale. A backward stepwise multivariable logistic regression was used to evaluate the primary outcome as a function of ED sedation depth. The primary outcome was hospital mortality, and secondary outcome was hospital length of stay. Of 294 mechanically ventilated ED patients, 79.9% received propofol and 63.6% were deeply sedated. There was a significant difference in median ED Richmond Agitation Sedation Scale (RASS) between survivors and non-survivors (p<0.001). After multivariable logistic regression that adjusted for severity of illness and confounding variables between survivors and non-survivors, ED RASS remained a non-significant variable for hospital mortality, and ICU RASS and APACHE II score were associated with hospital mortality.

Conclusion: Majority of mechanically ventilated patients receive deep sedation in the ED. ED RASS was not associated with hospital mortality.

Keywords: Emergency Department, Mechanical Ventilation, Sedation, Analgesia, ICU.