The impact of time to tracheostomy on mechanical ventilation duration, length of stay, and mortality in intensive care unit patients

Abstract

Introduction

This study examined the potential effects of time to tracheostomy on mechanical ventilation duration, intensive care unit (ICU), and hospital length of stay (LOS), and ICU and hospital mortality.

Methods

Cohort observational study was conducted in a tertiary care medical-surgical ICU based on a prospectively collected ICU database. We included 531 consecutive patients who were admitted between March 1999 and February 2005, and underwent tracheostomy during their ICU stay. The effect of time to tracheostomy on the different outcomes assessed was estimated using multivariate regression analyses (linear or logistic, based on the type of variables). Other independent variables that were included in the analyses included selected admission characteristics.

Results

Mean ± SD was 12.0 ± 7.3 days for time to tracheostomy, and 23.1 ± 18.9 days for ICU LOS. Time to tracheostomy was associated with an increased duration of mechanical ventilation (β-coefficient = 1.31 for each day; 95% confidence interval [CI], 1.14-1.48), ICU LOS (β-coefficient = 1.31 for each day; 95% CI, 1.13-1.48), and hospital LOS (β-coefficient = 1.80 for each day; 95% CI, 0.65-2.94). On the other hand, time to tracheostomy was not associated with increased ICU or hospital mortality.

Conclusions

Time to tracheostomy was independently associated with increased mechanical ventilation duration, ICU LOS, and hospital LOS, but was not associated with increased mortality. Performing tracheostomy earlier in the course of ICU stay may have an effect on ICU resources and could entail significant cost-savings without adversely affecting patient mortality.

Introduction

Tracheostomy is performed in 11% of mechanically ventilated patients and 6% of intensive care unit (ICU) patients in general [1], [2]. Although these proportions are small, patients with tracheostomy use substantial ICU resources, as they accounted for 26.2%, 21.0%, and 13.5% of all ventilator, ICU, and hospital days in the Project Impact database [2], respectively, and constituted 59% of patients staying in the ICU for more than 14 days in a study from our center [3]. Therefore, interventions that would decrease ICU length of stay (LOS) without adversely affecting outcome in this group of patients would likely result in significant cost-savings and improve resource utilization in the ICU.

Several studies have demonstrated that early tracheostomy is associated with decreased time to liberation from mechanical ventilation and decreased ICU LOS [4], [5], [6], [7], [8], [9], [10], [11]; however, there is still lack of consensus on what constitutes early vs late tracheostomy. This is evident from the fact that different cut-off points, ranging from 2 to 28 days, have been used for this definition [4], [5], [6], [7], [8], [12]. The purpose of this study was to assess the effect of time to tracheostomy on ICU LOS as well as on ICU and hospital mortality.