The Effect of Non-Invasive Mechanical Ventilation Duration in Acute Respiratory Failure

Non-invasive mechanical ventilation (NIMV) is an important factor for decreasing mortality and morbidity in patients with chronic obstructive pulmonary disease (COPD) with respiratory failure. The relation is not clear between NIMV success and optimal NIMV usage duration. In this study, we aimed to investigate the effect of NIMV duration (total, night-daytime, at one time) on the treatment success. 35 patients (25 M, 10 F) with COPD with respiratory failure were included in this study and their mean age was 66.7±8.6. Patients’ initial mean APACHE II score was 18.8±4.7, PaCO2 70.0±19.6, pH 7.31±0.9, respiratory rate 28.5±6.0. Patients who required mechanichal ventilation with tracheal intubation and death were defined as treatment failure (n=7). NIMV durations were 13.1±3.0 hour/day, 5.5±2.1 hour/daytime and 7.6±2.7 hour/night. The mean duration of stay in the ICU was 11.7±6.9 day and the avarage total NIMV duration was 79.6±56.3 hours. The mean NIMV duration at one time was 2.7±0.9 hours and NIMV was used 4.7±1.7 times in a day. In logistic regression analysis, the total, nightday time and at one time duration of NIMV usage was not associated with the treatment failure but the duration of all day NIMV usage was significantly lower in the success group than failure group. The high APACHE II scorewas alsoa predicting factor for the treatment failure. We concluded that NIMV duration except duration of NIMV usage all day, is not a factor for the treatment success in patients with COPD with respiratory failure, however APACHE II score affects the treatment success.