EFFECTS OF POSITIVE AIRWAY PRESSURE VENTILATION DURING CARDIOPULMONARY BYPASS ON POST-OPERATIVE PULMONARY OXYGENATION

Abstract

Objective: To evaluate the impact of continuous positive airway pressure duringcardiac surgery on post-operative pulmonary dysfunction after coronary arterybypass grafting.

Methodology: This randomized control trial was conducted in Chaudhry PervaizEllahi Institute of Cardiology, Multan from January 2016 to July 2016. All patientsmeeting the inclusion criteria who were planned to undergo CABG surgery usingcardiopulmonary bypass were selected. Patients were randomly allocated intotwo groups. Group I: (CPAP group): in this group continuous positive airwaypressure was continued after application of aortic cross clamp during surgery.Group II (Study group): in this group ventilation was kept stopped during thewhole surgical procedure. P< 0.05 was considered significant.

Results: Total of 150 patients were divided in two equal groups of 125 patientseach. No significant difference between age and gender of patients in CPAP andcontrol group was observered. Mean bypass time and cross-clamp time wasalso same in two groups. PaO2/FiO2 Ratio after one hour and four hour of surgerywas significantly high in CPAP group as compared to Non-ventilation group withp=0.001 and 0.03 respectively. Alveolar-arterial oxygen gradient after one hourof extubation was 21.47+1.03 kPa in CPAP group versus 27.73+2.19 kPa innon-ventilation group with p=0.001. Similarly alveolar-arterial oxygen gradientafter four hours of surgery was also significantly less in CPAP group 19.18+2.04kPa versus 20.80+2.57 kPa in non-ventilation group with p=0.001. Mechanicalventilation time after surgery was also significantly less in CPAP group5.12+1.89 hours in CPAP group versus 6.36+2.57 hours in non-ventilationgroup (p = 0.001).

Conclusion: Application of continuous positive airway pressure (CPAP) at 10 cmof H O during cardiopulmonary bypass had a significant positive impact on post- 2operative pulmonary oxygenation.