Protocol-driven weaning from mechanical ventilation: a study into adherence and outcomes

Introduction

Numerous studies have shown that ventilator weaning protocols are likely to reduce the duration of mechanical ventilation and ICU stay. In 2001 a taskforce of pulmonary and critical care experts developed guidelines for weaning and discontinuation of mechanical ventilation that recommended the development and implementation of respiratory weaning protocols for nonphysician healthcare professionals in the ICU [1]. Our weaning protocol was established in 2005 based on clinical evidence and best-practice recommendation at the time. The primary aim of this audit is to ascertain the extent of protocol adherence in our unit. The secondary aims include correlation of protocol-driven weaning to outcome as defined by successful extubation and reduction in the length of mechanical ventilation.

Methods

A prospective study of all patients who received mechanical ventilation over a 1-month period, excluding patients who had tracheostomy insertion and patients who had their treatment withdrawn. We looked at the rate of compliance with our weaning protocol, the reason for noncompliance and outcome.

Results

Fifty-two patients were included, 18 protocol-driven and 34 nonprotocol-driven weaning. The most common reason for nonprotocol weaning was clinical decision (40.4%). In total, 19.2% of patients had an alternative spontaneous breathing trial from the protocol and were counted as nonprotocol. There were no differences in the rate of successful extubation between patients who were weaned from protocol versus nonprotocol, 94.4% vs. 79.4% respectively (Fisher's exact test P = 0.236). Duration of ventilation was also similar in the protocol and nonprotocol groups, mean ± SEM = 84.7 ± 16.6 vs. 76.4 ± 12.8 hours (unpaired t test P = 0.699). The overall success rate of extubation was 86.5%.

Conclusion

Our compliance rate is 34.6%, and the protocol-driven weaning trial does not improve outcome in our unit. However this could be due to the small sample size, the timing of the study and a nondiscriminatory protocol.