RESUMO
BACKGROUND: Identifying patients at high risk of post-extubation acute respiratory failure requiring respiratory or mechanical cough assistance remains challenging. Here, our primary aim was to evaluate the accuracy of easily collected parameters obtained before or just after extubation in predicting the risk of post-extubation acute respiratory failure requiring, at best, noninvasive mechanical ventilation (NIV) and/or mechanical cough assistance and, at worst, reintubation after extubation. METHODS: We conducted a multicenter prospective, open-label, observational study from April 2012 through April 2015. Patients who passed a weaning test after at least 72 h of endotracheal mechanical ventilation (MV) were included. Just before extubation, spirometry and maximal pressures were measured by a technician. The results were not disclosed to the bedside physicians. Patients were followed until discharge or death. RESULTS: Among 3458 patients admitted to the ICU, 730 received endotracheal MV for longer than 72 h and were then extubated; among these, 130 were included. At inclusion, the 130 patients had mean ICU stay and endotracheal MV durations both equal to 11 ± 4.2 days. After extubation, 36 patients required curative NIV, 7 both curative NIV and mechanical cough assistance, and 8 only mechanical cough assistance; 6 patients, all of whom first received NIV, required reintubation within 48 h. The group that required NIV after extubation had a significantly higher proportion of patients with chronic respiratory disease (P = 0.015), longer endotracheal MV duration at inclusion, and lower Medical Research Council (MRC) score (P = 0.02, P = 0.01, and P = 0.004, respectively). By multivariate analysis, forced vital capacity (FVC) and peak cough expiratory flow (PCEF) were independently associated with (NIV) and/or mechanical cough assistance and/or reintubation after extubation. Areas under the ROC curves for pre-extubation PCEF and FVC were 0.71 and 0.76, respectively. CONCLUSION: In conclusion, FVC measured before extubation correlates closely with FVC after extubation and may serve as an objective predictor of post-extubation respiratory failure requiring NIV and/or mechanical cough assistance and/or reintubation in heterogeneous populations of medical ICU patients. ClinicalTrials.gov as #NCT01564745.
RESUMO
OBJECTIVES: To investigate breathing-swallowing interactions in patients with chronic obstructive pulmonary disease requiring noninvasive mechanical ventilation and, if needed, to develop a technical modification of the ventilator designed to eliminate ventilator insufflations during swallowing. DESIGN: We conducted a prospective, open-label, interventional study. PATIENTS: Fifteen consecutive chronic obstructive pulmonary disease patients with exacerbations requiring ICU admission and NIV. INTERVENTIONS: Swallowing performance and breathing-swallowing interactions were investigated noninvasively by chin electromyography, cervical piezoelectric sensor, and inductive respiratory plethysmography. Two water-bolus sizes (5 and 10 mL) were tested in random order. Swallowing was tested with and without noninvasive mechanical ventilation, in random order. First, a standard mechanical ventilator capable of delivering noninvasive mechanical ventilation was used. Second, a marketed device was equipped with an off-switch for use during swallowing. MEASUREMENTS AND MAIN RESULTS: Swallowing performance and breathing-swallowing interactions were investigated noninvasively by chin electromyography, cervical piezoelectric sensor, and inductive respiratory plethysmography. Two water bolus sizes (5 and 10 mL) were tested in random order. Swallowing was tested with and without noninvasive mechanical ventilation in random order. First, a standard mechanical ventilator capable of delivering noninvasive mechanical ventilation was used. Swallowing efficiency, breathing-swallowing synchronization, and Borg Scale dyspnea scores improved significantly with noninvasive mechanical ventilation. However, swallowing induced ventilator triggering followed by autotriggering. To improve patient-ventilator synchrony, a marketed device was equipped with an off-switch for use during swallowing. This device completely eliminated swallowing-induced ventilator triggering and postswallow autotriggering. CONCLUSION: Patients with chronic obstructive pulmonary disease admitted to the ICU for acute exacerbations had abnormal breathing-swallowing interactions and dyspnea, which improved with noninvasive mechanical ventilation. Furthermore, a ventilator device with a simple switch-off pushbutton to eliminate insufflations during swallows prevented swallowing-induced ventilator triggering and postswallow autotriggering.
