Low Tidal Ventilation During Bypass in Coronary Artery Bypass Reducing Post Operative Atelectasis and Pneumonia

Background: Postoperative pulmonary complications are frequent after coronary artery bypass grafting (CABG), and the contribution of low tidal volume ventilation during cardiopulmonary bypass (CPB) to pneumonia and atelectasis prevention is still unclear. The main objective is to determine the rates of postoperative pneumonia and atelectasis in patients during the CABG surgery and LTV ventilation during CPB, and to determine their relationships with the demographic and intraoperative parameters. Methods: This descriptive observational study was carried out at the Department of Cardiac Surgery, National Institute of Cardiovascular Diseases (NICVD), Karachi. A consecutive non-probability method was used to include 185 patients aged between 30 and 75 years due to an urgent need of CABG. LTV in CPB was 3-4ml/kg ideal body weight and respiratory rate was 10breaths/minute. Based on standardized clinical and radiological criteria there was postoperative pneumonia and atelectasis. SPSS version 26 was used to analyze the data and p-value was set at 0.05. Results: The average age was 54.43 ± 6.51years and 136 (73.5 %) were men. There were 15 patients (8.1%) with pneumonia and 31 patients (16.75%) with atelectasis. No statistically significant correlations of these complications with the demographic features, comorbidities or intraoperative parameters of ventilation were found. Conclusion: Pneumonia and atelectasis were identified in CABG patients ventilated with LTV during CPB, however none of the perioperative factors were found to relate significantly to pneumonia or atelectasis occurrence.