Effect of pressure support vs unassisted breathing through a tracheostomy collar on weaning duration in patients requiring prolonged mechanical ventilation: a randomized trial

Abstract

Importance: Patients requiring prolonged mechanical ventilation (>21 days) are commonly weaned at long-term acute care hospitals (LTACHs). The most effective method of weaning such patients has not been investigated.

Objective: To compare weaning duration with pressure support vs unassisted breathing through a tracheostomy collar in patients transferred to an LTACH for weaning from prolonged ventilation.

Design, setting, and participants: Between 2000 and 2010, a randomized study was conducted in tracheotomized patients transferred to a single LTACH for weaning from prolonged ventilation. Of 500 patients who underwent a 5-day screening procedure, 316 did not tolerate the procedure and were randomly assigned to receive weaning with pressure support (n = 155) or a tracheostomy collar (n = 161). Survival at 6- and 12-month time points was also determined.

Main outcome measure: Primary outcome was weaning duration. Secondary outcome was survival at 6 and 12 months after enrollment.

Results: Of 316 patients, 4 were withdrawn and not included in analysis. Of 152 patients in the pressure-support group, 68 (44.7%) were weaned; 22 (14.5%) died. Of 160 patients in the tracheostomy collar group, 85 (53.1%) were weaned; 16 (10.0%) died. Median weaning time was shorter with tracheostomy collar use (15 days; interquartile range [IQR], 8-25) than with pressure support (19 days; IQR, 12-31), P = .004. The hazard ratio (HR) for successful weaning rate was higher with tracheostomy collar use than with pressure support (HR, 1.43; 95% CI, 1.03-1.98; P = .033) after adjusting for baseline clinical covariates. Use of the tracheostomy collar achieved faster weaning than did pressure support among patients who did not tolerate the screening procedure between 12 and 120 hours (HR, 3.33; 95% CI, 1.44-7.70; P = .005), whereas weaning time was equivalent with the 2 methods in patients who did not tolerate the screening procedure within 0 to 12 hours. Mortality was equivalent in the pressure-support and tracheostomy collar groups at 6 months (55.92% vs 51.25%; 4.67% difference, 95% CI, -6.4% to 15.7%) and at 12 months (66.45% vs 60.00%; 6.45% difference, 95% CI, -4.2% to 17.1%).

Conclusion and relevance: Among patients requiring prolonged mechanical ventilation and treated at a single long-term care facility, unassisted breathing through a tracheostomy, compared with pressure support, resulted in shorter median weaning time, although weaning mode had no effect on survival at 6 and 12 months.

Trial registration: clinicaltrials.gov Identifier: NCT01541462.

Conflict of interest statement

All authors declare that they have no conflict of interest. MJT declares receipt of royalties from McGraw-Hill for two books published on critical care medicine.

Figures

Figure 1

Flow of patients in study cohort. *Patients were withdrawn based on their request, surrogate request, or the request of the attending physician who was not part of the research team. **A patient was judged to be unweanable by the attending physician (who was not part of the research team) and the attending physician then transferred the patient to another facility or to home.

Figure 2

Proportion of patients remaining on mechanical ventilation in the pressure-support and trach-collar arms. Bars represent plus SE or minus SE

Figure 3

Proportion of patients remaining on mechanical ventilation in the pressure-support and trach-collar arms based on the time taken to fail the five-day screening procedure: early-failure group (A) and late-failure group (B). Bars represent plus SE or minus SE