A total of 76 ARF patients were given an initial trial of NIV, out of which 49 (69%) patients succeeded, while 27 (31%) had to be intubated. The difference in the baseline characteristics,

severity of illness and reasons for ARF between the patients who succeeded and failed the initial NIV trial were shown in Table1. Patients who failed the initial NIV treatment were younger and mostly non-Caucasians. As compared to ARF patients who passed NIV trial successfully, more acute lung injury/acute respiratory TAM Receptor inhibitor distress syndrome (ALI/ARDS) and less COPD cases were present Inhibitors,research,lifescience,medical in the ARF patients who had to be intubated (Table1). In the multivariate analysis, the development of ALI/ARDS and higher APACHE III scores were associated with the failure of initial NIV treatment (Table2). NIV was also used in the weaning process for 24 (16%) ARF patients following IMV, of which 14 (58%) patients were re-intubated. Inhibitors,research,lifescience,medical Table 1 Baseline characteristics between success and failure of initial NIV treatment Table 2 Multivariate analysis of failure of NIV Forty-six patients chose NIV as their ceiling therapy, among which 37 (10%) ARF

patients were started on palliative NIV and 9 patients were initiated NIV after the withdrawal of IMV. The major etiology for those 37 patients initiated with palliative NIV was AECOPD (51%). As compared to those without COPD who were started with palliative NIV, the hospital mortality Inhibitors,research,lifescience,medical was significantly lower in the COPD patients Inhibitors,research,lifescience,medical (32% vs. 72%, p=0.01). Among the survivors, median survival time was significantly longer in patients with COPD (53days, 95% CI 9–232) as compared to patients without COPD (8days, 95% CI 4–30, p=0.02) (Figure2). However, when the analysis

were restricted in patients with COPD who had treatment Inhibitors,research,lifescience,medical limitation versus who did not, patients with treatment limitation had much higher hospital mortality even after adjusting for the baseline disease severity (32% vs. 0, p<0.001) (Table3). Figure 2 Long-term survivals between COPD and no-COPD patients on palliative NIV use COPD=Chronic Obstructive Pulmonary Disease NIV=non invasive mechanical ventilation. Table 3 The comparison between patients with and without treatment limitation Discussion In this study, we showed that NIV was commonly used in critically ill patients with ARF. NIV was used in two-third of the patients with ARF for the initial treatment and palliative care. Twenty percent of patients with ARF failed the PDK4 initial trial of NIV and had to be intubated. NIV trial usually could not rescue the patients with higher severity of illness and the development of ALI/ARDS. We did not observe any significant difference in mortality between the patients who were initially supported with NIV versus IMV. Palliative NIV did not only alleviate respiratory distress but also extend the long-term survival among COPD patients who selected NIV as the ceiling therapy.