Noninvasive ventilation as a systematic extubation and weaning technique in acute-on-chronic respiratory failure - A prospective, randomized controlled study

Prolonged duration of endotracheal mechanical ventilation (ETMV) is associa ted with an increased morbidity and mortality in intensive care unit (ICU) patients. The aim of this study was to assess the usefulness of noninvasive ventilation (NIV) as a systematic extubation and weaning technique to redu ce the duration of ETMV in acute-on-chronic respiratory failure (ACRF). Amo ng 53 consecutively intubated patients admitted for ACRF, we conducted a pr ospective, randomized controlled trial of weaning in 33 patients who failed a 2-h T-piece weaning trial (2 h-WT) although they met simple criteria for weaning. Conventional invasive pressure support ventilation (IPSV) was use d as the control weaning technique in 16 patients (IPSV group), and NIV was applied immediately after extubation in 17 patients (NIV group). The two w eaning groups were similar for type of chronic respiratory failure (CRF), p ulmonary function data, age, Simplified Acute Physiology Score (SAPS II), a nd severity of ACRF on admission. The characteristics of the two groups wer e also similar at randomization. In the IPSV group, 12 of 16 patients (75%) were successfully weaned and extubated, versus 13 of 17 (76.5%) in the NIV group (p = NS). NIV like IPSV significantly and similarly improved gas exc hange in relation to that achieved during 2 h-WT (p < 0.05). The duration o f ETMV was significantly shorter in the NIV (4.56 +/- 1.85 d) than in the I PSV group (7.69 +/- 3.79 d) (p = 0.004). NIV also reduced the mean period o f daily ventilatory support, but increased the total duration of ventilator y support related to weaning (3.46 +/- 1.42 d, versus 11.54 +/- 5.24 d with NIV; p = 0.0001). Most patients in the IPSV group developed complications related to ETMV and/or the weaning process, but the difference was not sign ificant (nine of 16 versus six of 17). The durations of ICU and hospital st ays and the 3-mo survival were similar in the two groups. In conclusion, NI V permits earlier removal of the endotracheal tube than with conventional I PSV, and reduces the duration of daily ventilatory support without increasi ng the risk of weaning failures. NIV should be considered as a new and usef ul systematic approach to weaning in patients with ACRF who are difficult t o wean.