Noninvasive ventilation for acute respiratory failure: pressure support ventilation versus pressure controlled ventilation

Abstract

Background: The best ventilator mode for patients receiving noninvasive ventilation (NIV) is unknown. Aims and Objectives: To compare the effectiveness of two pressure modes (i.e., pressure support ventilation [PSV] and pressure controlled ventilation [PCV]) in patients receiving NIV. Methods: This was a prospective observational study of adult patients who were admitted to 20 intensive care units (ICUs) and received NIV treatment for acute respiratory failure. Results: Among 156 patients receiving NIV, 29 were treated with PCV mode and 59 treated with PSV mode. The mean age was 73.3 years and mean body mass index 21.0 kg/m2. There were no differences both in underlying lung diseases and in primary causes for NIV in both groups. However, applied inspiratory positive airway pressure (IPAP) was higher in patients with PCV than those with PSV (18.0 vs. 15.0 cm H2O). More patients with PCV received sedatives and experienced dry mouth than those with PSV did. Twenty-four (27.2%) patients experienced NIV failure and 13 (14.8%) died in hospital. Although the PSV mode showed a tendency for higher survival rate, the mode was a significant factor for NIV success (odds ratio [OR], 2.303; 95% confidence interval, 1.216 to 4.360) in multivariate analysis. In addition, immunocompromised state, de novo respiratory failure, post-NIV respiratory rate were inversely associated with NIV success. Conclusions: Contrary to PCV mode, PSV mode was a significant factor associated with NIV success in the ICU settings.