Immediate changes in hemodynamics and gas exchange after initiation of noninvasive ventilation in cardiac surgical patients

Abstract

Introduction: Cardiac surgery is associated with pulmonary dysfunction and complications such as prolonged intubation and reintubation. Bilevel positive airway pressure (BiPAP) machine has been used in the clinical settings to improve oxygenation, reduce work of breathing, and avoid reintubation. The effect of BiPAP on cardiovascular parameters is not well established, and very few studies have targeted hemodynamic changes. The aim of the study was to assess the immediate effect of BiPAP on respiratory and hemodynamic parameters in post-cardiac surgery patients. Materials and Methods: This quasi-experimental study was done on 33 adult cardiac surgery patients. Ethical review committee approval was sought and consent was taken. All patients who were in respiratory distress with respiratory rate of >30/min and/or PaO2:FiO2 ratio of <200 were included. Hemodynamic and respiratory parameters were recorded just before and 15 min after BiPAP application. Sample size was determined on the basis of BiPAP effect on one of the variables, PaO2:FiO2 ratio. Results: A total of 33 patients were included in the study. The average age of the patients was 60.97 ± 10.8, of which 23 (69.7%) were males and 10 (30.7%) females. BiPAP application leads to statistically significant improvement in ventilator parameters including SaO2 29 (87.7%), PaO2 29 (87.8%), PaCO2 21 (63.6%), and PaO2:FiO2 ratio in 27 (81.8%). Conclusion: Ventilatory parameters were significantly improved after BiPAP application in this study, but hemodynamic parameters showed no statistically significant change. BiPAP application was also able to decrease the need for reintubation in post-cardiac surgery patients.

Keywords

• gas exchange
• hemodynamics
• noninvasive ventilation
• oxygen