Abstract
Previous studies reported that noninvasive positive pressure ventilation (NPPV) may have beneficial effects in the treatment of patients with congestive heart failure (CHF). However, a little is known, until now, about the haemodynamic and respiratory consequences of bilevel positive airway pressure (BiPAP) therapy in these patients. This study prospectively evaluated the haemodynamic and respiratory effects of BiPAP, as a type of NPPV, on patients with CHF with systolic and/or diastolic dysfunction. A total of 40 patients (32 males and 8 females) were enrolled in this study. They were divided into 4 groups as follow: 10 without heart failure as a control group (group A), 10 with systolic heart failure (group B), 10 with diastolic heart failure (group C), and lastly 10 patients with systolic and diastolic heart failure (group D). Each patient underwent chest X-ray, pulmonary function tests, blood picture, blood sugar and liver and kidney function tests. Echocardiography and blood gases were performed before ventilation, 60 minutes of the beginning of ventilation, and then 30 minutes after the end of ventilation. Oxygen saturation monitoring, blood pressure monitoring, ECG and heart rate monitoring, respiratory rate monitoring and daytime polysomnography were performed throughout the study. Each patient received NPPV (an inspiratory pressure of 12 cm H2O and an expiratory pressure of 4 cm H2O in spontaneous mode) using a BiPAP ventilator via a full-face mask for one hour. As regard the haemodynamic effects, in comparison to spontaneous breathing, no significant statistical changes were found in the systolic or diastolic parameters in group A after 60 minutes of BiPAP application apart from statistically significant decrease in the systolic blood pressure (p=0.03). In groups B, C and D BiPAP produced significant decreases in left ventricular end-diastolic and end-systolic volumes as well as heart rate (p<0.05). Ejection fraction, stroke volume and cardiac output significantly increased. Blood pressure measurements and diastolic parameters showed no significant changes (p>0.05). With the exception of nonsignificant changes in respiratory rate in group A, respiratory measurements showed statistically significant increase in arterial oxygen tension, significant decrease in arterial carbon dioxide tension, significant increase in oxygen saturation and significant decrease in respiratory rate with application of BiPAP in all groups. In all groups, most of the haemodynamic and respiratory parameters returned to the baseline values after 30 minutes of BiPAP discontinuation. There were nonsignificant correlations between cardiac output after 60 minutes of BiPAP application and baseline haemodynamic and respiratory parameters in all groups. From this study it can be concluded that BiPAP has excellent potential for improving left ventricular performance of patients with CHF secondary to systolic and/or diastolic dysfunction.