Influence of high-intensity noninvasive positive pressure ventilation on biomarkers in stable hypercapnic COPD patients

Background: High-intensity noninvasive positive pressure ventilation (HI-NPPV) improves lung function parameters, blood gases, health-related quality of life and dyspnea during exertion in stable hypercapnic COPD. However, the underlying mechanism of these improvements remains unclear. Therefore, the present studies investigated the influence of HI-NPPV on a panel of cytokines and established cardiovascular biomarkers. Methods: Peripheral blood samples were drawn before and three month after the initiation of HI-NPPV and analyzed by flow cytometric bead array and ELISA. Results: Twenty COPD patients (FEV 1 31±17%pred.) were included. HI-NPPV (inspiratory positive airway pressure 23±4mbar) (breathing frequency 17±2/min) significantly improved PaCO 2 , both during daytime spontaneous breathing (p=0.005) and nighttime ventilation (p<0.001). Pro brain natriuretic peptide (proBNP) was significantly reduced by a mean of 578±1332ng/l after three months of HI-NPPV (p=0.017). There were no other significant changes with regard to inflammatory cytokines and cardiovascular biomarkers after three months of HI-NPPV. The reduction of PaCO 2 during daytime spontaneous breathing positively correlated with the reduction of proBNP (correlation coefficient 0.613; p=0.0197). Conclusion: HI-NPPV is not associated with improvements of a panel of inflammatory cytokines. However, the reduction of PaCO 2 during HI-NPPV was associated with a reduction of proBNP suggesting a pathophysiologic link between HI-NPPV and cardiovascular function. These findings might be due to direct effects on the myocardium or a reduction of hypercapnia-induced peripheral edema and warrant further investigations.