Improved analgesia, sedation, and delirium protocol associated with decreased duration of delirium and mechanical ventilation

Abstract

Rationale: Introduction of sedation protocols has been associated with improved patient outcomes. It is not known if an update to an existing high-quality sedation protocol, featuring increased patient assessment and reduced benzodiazepine exposure, is associated with improved patient process and outcome quality metrics.

Methods: This was an observational before (n = 703) and after (n = 780) cohort study of mechanically ventilated patients in a 24-bed trauma-surgical intensive care unit (ICU) from 2009 to 2011. The three main protocol updates were: (1) requirement to document Richmond Agitation Sedation Scale (RASS) scores every 4 hours, (2) requirement to document Confusion Assessment Method-ICU (CAM ICU) twice daily, and (3) systematic, protocolized deescalation of excess sedation. Multivariable linear regression was used for the primary analysis. The primary outcome was the duration of mechanical ventilation. Prespecified secondary endpoints included days of delirium; the frequency of patient assessment with the RASS and CAM-ICU instruments; benzodiazepine dosing; durations of mechanical ventilation, ICU stay, and hospitalization; and hospital mortality and ventilator associated pneumonia rate.

Results: Patients in the updated protocol cohort had 1.22 more RASS assessments per day (5.38 vs. 4.16; 95% confidence interval [CI], 1.05-1.39; P < 0.01) and 1.15 more CAM-ICU assessments per day (1.49 vs. 0.35; 95% CI, 1.08-1.21; P < 0.01) than the baseline cohort. The mean hourly benzodiazepine dose decreased by 34.8% (0.08 mg lorazepam equivalents/h; 0.15 vs. 0.23; P < 0.01). In the multivariable model, the median duration of mechanical ventilation decreased by 17.6% (95% CI, 0.6-31.7%; P = 0.04). The overall odds ratio of delirium was 0.67 (95% CI, 0.49-0.91; P = 0.01) comparing updated versus baseline cohort. A 12.4% reduction in median duration of ICU stay (95% CI, 0.5-22.8%; P = 0.04) and a 14.0% reduction in median duration of hospitalization (95% CI, 2.0-24.5%; P = 0.02) were also seen. No significant association with mortality (odds ratio, 1.18; 95% CI, 0.80-1.76; P = 0.40) was seen.

Conclusions: Implementation of an updated ICU analgesia, sedation, and delirium protocol was associated with an increase in RASS and CAM-ICU assessment and documentation; reduced hourly benzodiazepine dose; and decreased delirium and median durations of mechanical ventilation, ICU stay, and hospitalization.

Figure 1.

Hex plot of mean number of Richmond Agitation Sedation Scale (RASS) assessments per day versus mean RASS score per day, in baseline versus updated, sedation-reducing cohort. The darker hexes denote more observations. The updated cohort features a greater number of RASS assessments as well as a higher (less sedated) mean RASS score (P < 0.01 for both). Note: Both the y-axes scales and the number of observations per hex shade are different in the baseline and updated cohort figures.

Figure 3.

Plot of the probability of delirium over time if a Confusion Assessment Method–Intensive Care Unit (CAM-ICU) score was measured in the baseline cohort (red) and in the updated cohort (blue). The overall odds ratio of delirium in the first 16 days of ICU stay was 0.67 (95% confidence interval, 0.49–0.91; P = 0.01) comparing updated versus baseline cohort.

Figure 2.

Box plot of the adjusted duration of mechanical ventilation (hours) adjusted for SAPS, age, weight, and male sex in the baseline versus sedation-reducing protocol cohorts. The horizontal line at the center of the box denotes the median. The upper and lower boundaries signify the 75th and 25th percentiles, respectively. Outlying values are denoted with the box whiskers and dots. The updated cohort features a 17.6% reduction in the median duration of mechanical ventilation (95% confidence interval, 0.6–31.7%; P = 0.04).