Evaluation of the minute ventilation recovery time as a predictor of weaning in mechanically ventilated COPD patients in respiratory failure

BackgroundThere is still difficulty in discontinuing mechanical ventilation (MV) in chronic obstructive pulmonary disease (COPD) patients with respiratory failure and more than 50% of the time is spent for weaning. A large spectrum of weaning indices is used. In this study we evaluated minute ventilation recovery time (MVRT) that may be a new practical measure of the ability to predict weaning outcome.MethodsThe study was conducted on 50 mechanically ventilated Acute exacerbation of COPD patients admitted to the Zagazig University Hospitals intensive care units (ICUs) with a mean age of 61.8 ± 7.6 years, They were divided into 2 groups; group I: successful weaning, included 42 patients and group II: failed weaning, included 8 patients. Minute ventilation (VE) was recorded 30 min just after the institution of mechanical ventilation, then every 2 h for 24 h. Minute ventilation just before the spontaneous breathing trial (SBT) was recorded, and is compared to the previous recordings of minute ventilation, if this value (pre successful weaning VE) was about 110% of one of the recorded VE values, it is now considered as the baseline VE of the patients and the time passed from institution of M.V till such reading is considered as the MVRT of the patient.ResultsAmong 42 successfully weaned mechanically ventilated COPD patients, when compared between different weaning parameters, MVRT was significantly better as a predictor of weaning success (P = 0.002). MVRT had high sensitivity and specificity of 76% and 85%, respectively at a cutoff value of 11.7 h. MVRT had a strong correlation with weaning outcome in comparison to other weaning parameters used in the study.ConclusionThe minute ventilation recovery time is a good, reliable predictor of weaning success and it is the most independent parameter among other weaning predictors that can predict a successful spontaneous breathing trial (SBT).