BackgroundIdentifying the predictors of noninvasive ventilation (NIV) failure has attracted significant interest because of the strong link between failure and poor outcomes. However, very little attention has been paid to the timing of the failure. This narrative review focuses on the causes of NIV failure and risk factors and potential remedies for NIV failure, based on the timing factor.ResultsThe possible causes of immediate failure (within minutes to <1 h) are a weak cough reflex, excessive secretions, hypercapnic encephalopathy, intolerance, agitation, and patient-ventilator asynchrony. The major potential interventions include chest physiotherapeutic techniques, early fiberoptic bronchoscopy, changing ventilator settings, and judicious sedation. The risk factors for early failure (within 1 to 48 h) may differ for hypercapnic and hypoxemic respiratory failure. However, most cases of early failure are due to poor arterial blood gas (ABGs) and an inability to promptly correct them, increased severity of illness, and the persistence of a high respiratory rate. Despite a satisfactory initial response, late failure (48 h after NIV) can occur and may be related to sleep disturbance.ConclusionsEvery clinician dealing with NIV should be aware of these risk factors and the predicted parameters of NIV failure that may change during the application of NIV. Close monitoring is required to detect early and late signs of deterioration, thereby preventing unavoidable delays in intubation.

Colistin-induced renal toxicity may be attributable to oxidative damage. The combined treatment of colistin plus NAC seems to have a beneficial role in restoration of the oxidant injury which may be related to its antioxidant effect.

Chronic obstructive pulmonary disease patients with frequent exacerbations should be carefully assessed for modifiable confounding risk factors regardless of poor lung function to decrease exacerbation frequency and related poor prognosis.

Fungal pulmonary infections (FPIs) are frequent causes of mortality in hematopoietic stem cell transplantation (HSCT) recipients. Determination of the specific risk factors may improve the prognosis. The aim of this study was to evaluate the risk factors of FPIs due to HSCT. Patient history, physical examination, chest X-rays and the consultation records of the pulmonary disease department which were a part of the routine evaluation before and at first, third, sixth, ninth and twelfth months of HSCT were retrieved in 148 adult HSCT recipients. Results of the highresolution computed tomography, fiber-optic bronchoscopy and the microbiological data were also included. FPI was diagnosed in 22 patients (14.9%). Multivariate analysis showed that increased ferritin levels (41000 ng/ml; OR: 3.42, 95% CI 1.03-11.42, P ¼ 0.045) and the development of sinusoidal obstruction syndrome (SOS; OR: 5.09, 95% CI 1.53-16.90, P ¼ 0.008) were significant risk factors for FPIs. The sensitivity and specificity of ferritin 41000 ng/ml for the prediction of FPIs were 67 and 70%, respectively. There was a positive correlation between the increased risk of FPIs and pretransplantation ferritin levels (r ¼ 0.413, Po0.001) and increased ferritin levels and SOS (r ¼ 0.331, Po0.001). Increased pretransplantation ferritin levels and development of SOS are predictive factors of FPIs during HSCT.

This study showed that an increased FE(NO) level may be used for identifying patients with IBD who need further pulmonary evaluation.