WORK OF BREATHING AS A WEANING PARAMETER IN MECHANICALLY VENTILATED PATIENTS

Study objective: Predicting patient responses to changes in ventilatory support or weaning is primarily based on bedside measure of respiratory mechanics and clinical judgment, Work of breathing (WOB) has been considered to be the best predictive factor in weaning. This study evaluated patient WOE as a predictive measure of weaning and extubation. Design: Blinded, descriptive evaluation of the accuracy of preextubation values of patient WOE in predicting successful extubation. Setting: Critical care units of 500-bed major teaching hospital of the University of Hawaii. Patients: Twenty-four patients from the medical and surgical ICU were enrolled in the study Patient diagnoses included COPD, ARDS, pneumonia, and renal failure. Measurements and main results: In all patients, weaning from mechanical ventilation was accomplished by the clinical ICU teams who were blinded to the patient WOE. After extubation, patient WOE was compared with extubation attempts, Zn 14 patients, WOE was elevated above normal levels prior to successful extubation, while only 1 patient whose WOE was abnormal prior to extubation required reintubation within 24 h. WOB and clinical parameters were normal in 10 successfully extubated patients. Conclusions: In this group of mechanically ventilated patients, measurement of patient WOE was less accurate than conventional weaning parameters and clinical. judgment for predicting successful extubation, This clinical evaluation study suggests that WOB alone is inadequate as a weaning parameter.