Clinical Prediction of Weaning and Extubation in Australian and New Zealand Intensive Care Units

Abstract

Our objective was to describe, in Australian and New Zealand adult intensive care units, the relative frequency in which various clinical criteria were used to predict weaning and extubation, and the weaning methods employed. Participant intensivists at 55 intensive care units completed a self-administered questionnaire, using visual analogue scales (0=not at all predictive, 10=perfectly predictive, not used=null score) to record the perceived utility of 30 potential predictors. Survey response rate was 71% (164/230). Those variables thought most predictive of weaning readiness were respiratory rate (median score 8.0, interquartile range 7.0 to 8.6) effective cough (7.3, 5.9 to 8.2) and pressure support setting (7.2, 6.0 to 8.0). The most highly rated predictors of extubation success were effective cough (8.0, 7.0 to 9.0), respiratory rate (8.0, 7.0 to 8.5) and Glasgow Coma Score (7.9, 6.1 to 8.3). Variables perceived least predictive of weaning and extubation success were P0.1, Acute Physiological and Chronic Health Evaluation score II, mean arterial pressure, electrolytes and maximum inspiratory pressure (individual median scores <5). Most popular clinical criteria were those perceived to have high predictive accuracy, both for weaning (respiratory rate 96%, pressure support setting 94% and Glasgow coma score 91%) and extubation readiness (respiratory rate 98%, effective cough 94% and Glasgow Coma Score 92%). Weaning mostly employed pressure support ventilation (55%), with less use of synchronised intermittent mandatory ventilation (32%) and spontaneous breathing trials (13%). Classic ventilatory performance predictors including respiratory rate and effective cough were reported to be of greater clinical utility than other more recently proposed measures.