A randomized, controlled trial of protocol-directed versus physician-directed weaning from mechanical ventilation

Abstract

Objective: To compare a practice of protocol-directed weaning from mechanical ventilation implemented by nurses and respiratory therapists with traditional physician-directed weaning.

Design: Randomized, controlled trial.

Setting: Medical and surgical intensive care units in two university-affiliated teaching hospitals.

Patients: Patients requiring mechanical ventilation (n = 357).

Interventions: Patients were randomly assigned to receive either protocol-directed (n = 179) or physician-directed (n = 178) weaning from mechanical ventilation.

Measurements and main results: The primary outcome measure was the duration of mechanical ventilation from tracheal intubation until discontinuation of mechanical ventilation. Other outcome measures included need for reintubation, length of hospital stay, hospital mortality rate, and hospital costs. The median duration of mechanical ventilation was 35 hrs for the protocol-directed group (first quartile 15 hrs; third quartile 114 hrs) compared with 44 hrs for the physician-directed group (first quartile 21 hrs; third quartile 209 hrs). Kaplan-Meier analysis demonstrated that patients randomized to protocol-directed weaning had significantly shorter durations of mechanical ventilation compared with patients randomized to physician-directed weaning (chi 2 = 3.62, p = .057, log-rank test; chi 2 = 5.12, p = .024, Wilcoxon test). Cox proportional-hazards regression analysis, adjusting for other covariates, showed that the rate of successful weaning was significantly greater for patients receiving protocol-directed weaning compared with patients receiving physician-directed weaning (risk ratio 1.31; 95% confidence interval 1.15 to 1.50; p = .039). The hospital mortality rates for the two treatment groups were similar (protocol-directed 22.3% vs. physician-directed 23.6%; p = .779). Hospital cost savings for patients in the protocol-directed group were $42,960 compared with hospital costs for patients in the physician-directed group.

Conclusion: Protocol-guided weaning of mechanical ventilation, as performed by nurses and respiratory therapists, is safe and led to extubation more rapidly than physician-directed weaning.