Variation in Depth of Sedation Targeted and Achieved among Mechanically Ventilated Patients and Associated Outcomes

Abstract

Introduction: Sedative agents are commonly administered to patients receiving mechanical ventilation (MV). Practice guidelines recommend provision of light sedation within validated scoring systems (e.g., Richmond Agitation Sedation Scale [RASS]), but recognize some circumstances require deeper sedation. The real-world approaches to depth of sedation, and the impact of hospital sedation practices on patient outcomes, remain uncharacterized. Methods: We used the US based eICU collaborative research database to identify adult patients who received MV > 24 hours, who did not have a diagnosis that may require sedatives for indications other than facilitating MV, and who had recorded RASS goals and scores. We used mixed effects regression models to determine factors associated with initial RASS goals and rates of RASS score-goal concordance. We organized hospitals into quartiles of risk-adjusted RASS score-goal concordance, and used g-computation to evaluate differences in ventilator free days (VFD) at hospital day 28. Results: We identified a study sample of 1,650 adult patients (at 21 hospitals) who met inclusion/exclusion criteria. Hospital-level risk-adjusted initial RASS goals ranged from -1.4 to 0.2, and hospital-level risk-adjusted RASS score-goal concordance ranged from 27% to 64%. Patients admitted to hospitals in the highest quartile of score-goal concordance (quartile 4) were generally targeted for deeper sedation (median RASS goal -1.31) than patients admitted to hospitals in the lowest quartile (quartile 1) (median RASS goal -0.58). Compared to patients admitted to quartile 1 hospitals, patients at quartile 4 hospitals experienced fewer VFDs (adjusted incidence risk difference -2.4, 95% CI -4.26 to -0.36). Conclusion: US hospitals prescribe RASS goals in line with guideline recommendations for light sedation, but there is wide variation in achieving these RASS goals. Hospitals with higher RASS score-goal concordance typically prescribed deeper RASS goals, and patients admitted to these hospitals experienced fewer VFD.