Evaluation of a minimal sedation protocol using ICU sedative consumption as a monitoring tool: a quality improvement multicenter project

Abstract

Introduction: Oversedation frequently occurs in ICUs. We aimed to evaluate a minimal sedation policy, using sedative consumption as a monitoring tool, in a network of ICUs targeting decrement of oversedation and mechanical ventilation (MV) duration.

Methods: A prospective quality improvement project was conducted in ten ICUs within a network of nonteaching hospitals in Brazil during a 2-year period (2010 to 2012). In the first 12 months (the preintervention period), we conducted an audit to identify sedation practice and barriers to current guideline-based practice regarding sedation. In the postintervention period, we implemented a multifaceted program, including multidisciplinary daily rounds, and monthly audits focusing on sedative consumption, feedback and benchmarking purposes. To analyze the effect of the campaign, we fit an interrupted time series (ITS). To account for variability among the network ICUs, we fit a hierarchical model.

Results: During the study period, 21% of patients received MV (4,851/22,963). In the postintervention period, the length of MV was lower (3.91 ± 6.2 days versus 3.15 ± 4.6 days; mean difference, -0.76 (95% CI, -1.10; -0.43), P <0.001) and 28 ventilator-free days were higher (16.07 ± 12.2 days versus 18.33 ± 11.6 days; mean difference, 2.30 (95% CI, 1.57; 3.00), P <0.001) than in the preintervention period. Midazolam consumption (in milligrams per day of MV) decreased from 329 ± 70 mg/day to 163 ± 115 mg/day (mean difference, -167 (95% CI, -246; -87), P <0.001). In contrast, consumption of propofol (P = 0.007), dexmedetomidine (P = 0.017) and haloperidol (P = 0.002) increased in the postintervention period, without changes in the consumption of fentanyl. Through ITS, age (P = 0.574) and Simplified Acute Physiology Score III (P = 0.176) remained stable. The length of MV showed a secular effect (secular trend β(1) = -0.055, P = 0.012) and a strong decrease immediately after the intervention (intervention β(2) = -0.976, P <0.001). The impact was maintained over the course of one year, despite the waning trend for the intervention's effect (postintervention trend β(3)= 0.039, P = 0.095).

Conclusions: By using a light sedation policy in a group of nonteaching hospitals, we reproduced the benefits that have previously been demonstrated in controlled settings. Furthermore, systematic monitoring of sedative consumption should be a feasible instrument for supporting the implementation of a protocol on a large scale.

Figure 1

The minimal sedation protocol algorithm.

Figure 2

Monthly consumption in mg of sedoanalgesic medications. (A) Midazolam. (B) Propofol. (C) Fentanyl. (D) Dexmedetomidine.

Figure 3

Comparisons of length of mechanical ventilation and midazolam consumption among units in each of the ten units in the quality improvement project. (A) Length of mechanical ventilation. (B) Midazolam consumption. (C) Midazolam consumption per day of mechanical ventilation (MV). The red line denotes the only unit which showed an inclination toward increased length of mechanical ventilation in the period (mean difference, 0.83 (95% CI, −1.10; 2.76), P = 0.38).

Figure 4

Interrupted time series from the autoregressive integrated moving average model. Length of mechanical ventilation (MV) (A) and adjusted midazolam consumption (B) over time. Solid black circles represent the average data per month. Solid black line represents the fitted line for the observed data after the protocol implementation. Gray dashed line represents the forecasted values from the model if the protocol was not implemented during the period. Yellow dashed line represents when the intervention began.

Figure 5

Results from the hierarchical time series model. Length of mechanical ventilation (MV) (A) and adjusted midazolam consumption (B) over time. Level 0 denotes the modeled time series using a bottom-up method for the entire network. Level 1 denotes the independent time series for each of the ten units analyzed. Dashed black lines represent when the intervention began.

Figure 6

Association between midazolam consumption and length of mechanical ventilation. A positive, nonlinear association between midazolam and length of mechanical ventilation was found (P = 0.022) in a mixed linear model. Each point represent the variable per each intensive care unit per month. x- and y-axes are in natural logarithmic scale. Solid gray line represents the best fit between variables. Blue bands represent the 95% of confidence interval from the fit.