The Effect of Open Lung Ventilation on Respiratory Mechanics, Postoperative Organ Function, and Inflammatory Mediators in Coronary Artery Bypass Surgery

Original Articles - Clinical medicine (Article Number: e۵۶۳۳۱) Background and Objective: The present study aimed to assess the supportive role of open lung ventilation on respiratory mechanics, the rate of oxygenation, inflammatory biomarkers, and probable liver or renal injuries following coronary artery bypass grafting surgery. Materials and Methods: This randomized double-blinded clinical trial study was conducted on ۶۴ candidates for coronary artery bypass surgery using a cardiopulmonary pump. The patients were randomly categorized into the Positive end-expiratory pressure (PEEP) group (n = ۳۲) or Zero End Expiratory Pressure (ZEEP) group (n = ۳۲). Results: Interleukin-۶ levels were similar between the PEEP and ZEEP groups before surgery (p = ۰.۱۸) and were significantly higher in the ZEEP group after pump insertion (p = ۰.۰۰۵). On the contrary, the levels of Interleukin-۶ were significantly higher in the PEEP group after extubation (p = ۰.۰۰۱). The Between-group analysis also showed a significant difference between the levels of interleukin-۶ in the ZEEP and PEEP groups, representing a greater increase in the PEEP group (p < ۰.۰۰۱). There was no difference in certain hemodynamic parameters, including heart rate, mean blood pressure, mean CO۲ pressure (PCO۲), mean concentration of HCO۳, and base excess. The mean arterial O۲ saturation was higher overall in the PEEP group compared to the ZEEP group. The mean PaO۲/FiO۲ was significantly higher in the PEEP than in the ZEEP group (p < ۰.۰۰۱). Conclusion: Supportive ventilation technique leads to better oxygenation and better lung expansion, as well as lowering inflammatory biomarkers, after coronary artery bypass surgery.

Keywords:

Coronary Artery Bypass , Pulmonary Ventilation , Interleukin-۶ , Positive-Pressure Respiration