Failure of noninvasive ventilation after lung surgery: a comprehensive analysis of incidence and possible risk factors.

OBJECTIVE Noninvasive ventilation has been successfully used after thoracic surgery. However, noninvasive ventilation fails in about 20% of patients. The aim of the study was to analyze episodes of noninvasive ventilation failure and to assess possible risk factors, while taking into account the performance of fiberoptic bronchoscopy for secretion management. METHODS From January 2006 to June 2008, the use of noninvasive ventilation was prospectively recorded after thoracic surgery. Data were retrospectively abstracted from charts, including the number of fiberoptic bronchoscopies performed. Risk factors associated with noninvasive ventilation failure were evaluated using logistic regression analysis to estimate odds ratios (ORs) and their 95% confidence intervals (CIs). RESULTS During the study period, 664 patients were admitted in the intensive care unit (ICU) after lung resection or pulmonary thromboendarterectomy. A total of 135 patients underwent noninvasive ventilation (20.3%). As many as 40 of these 135 patients needed to be intubated (29.6%) and represented the noninvasive ventilation failure group. Patients with noninvasive ventilation failure had more fiberoptic bronchoscopies performed compared with patients with noninvasive ventilation success: 3 (1-5) versus 1 (0-3); p = 0.0008. Four independent variables were associated with noninvasive ventilation failure during the first 48 h of appliance: increased respiratory rate (OR: 4.17 (1.63-10.67); increased Sequential Organ Failure Assessment (SOFA) score (OR: 3.05 (1.12-8.34); number of fiberoptic bronchoscopies performed (OR: 1.60 (1.01-2.54); and number of hours spent on noninvasive ventilation (OR: 1.06 (1.01-1.11). Nosocomial pneumonia was the leading cause of respiratory complications and occurred in 21 and 6 patients with and without noninvasive ventilation failure, respectively (53% vs 6%; p < 0.0001). Patients in the failure group had a higher mortality rate (20% vs 0%; p < 0.0001). CONCLUSIONS Noninvasive ventilation failure is associated with higher mortality, but is merely a marker of progression of a more severe disease. This may at least indicate the need for caution in some patients. Interestingly, increased use of fiberoptic bronchoscopies during noninvasive ventilation appliance was identified as a risk factor of failure.