efficiency and outcome of non-invasive versus invasive positive pressure ventilation therapy in respiratory failure due to chronic obstructive pulmonary disease

background: application noninvasive ventilation in the patients with exacerbation of chronic obstructive pulmonary disease (copd) reduced mortality. this case-control study was designed to compare efficiency and outcome of non-invasive (niv) versus invasive positive pressure ventilation (ippv) in respiratory failure due to copd methods: the patients were assigned to niv or ippv intermittantly.the clinical parameters, including rr (respiratory rate), bp (blood pressure), hr (heart rate) and ph, paco2, pao2 before and 1, 4 and 24 h after treatment were measured. demographic information such as age, sex, severity of disease based on apache score, length of stay and outcome were recorded results: fifty patients were enrolled in the niv group and 50 patients in ippv. the mean age was 70.5 in niv and 63.9 in invasive ventilation group (p>0.05). in ippv group, the average values of ph: pco2: and po2, were 7.22±0.11, 69.64 + 24.25: and 68.86±24.41 .in niv, the respective values were 7.30±0.07, 83.94±18.95, and 60.60±19.88.  in niv group, after 1, 4 and 24 h treatment, the clinical and ventilation parameters were stable. the mean apache score in was ippv, 26.46±5.45 and in niv was 12.26±5.54 (p<0.05). the average length of hospital stay in ippv was 15.90±10 and in niv 8.12±6.49 days (p<0.05). the total mortality in the niv was 4 (8%) and in ippv, 27 patients (54%) (p<0.05). conclusion: this study indicates that using nippv is a useful therapeutic mode of treatment for respiratory failure with acceptable success rate and lower mortality. the application of nippv reduces hospital stay, intubation and its consequent complications