Analysis of Different Tidal Volumes on Ventilatory Mechanics and Arterial Blood Gas Variables in Patients Undergoing Cardiac Surgery.

Introduction: Cardiovascular diseases have been increasing gradually each year, and their incidence has reached 80%. Mechanical ventilation (MV) is essential in the postoperative period of cardiac surgery (CS) due to anesthetic induction. The tidal volume (TV) is a parameter that depends on the conditions of the respiratory system mechanics, aiming at the reduction of dynamic hyperinflation. Objective: Analyze the effect of different TVs on blood gas analysis variables and respiratory mechanics in patients submitted to CS. Materials and methods: This was an uncontrolled randomized clinical trial. Patients were randomized by lottery into the following two groups: One group was ventilated with a TV of 6 mL/kg; while the other received a TV of 8 mL/kg. After 30 minutes of admission with the VT, blood gas analysis data were evaluated, such as pH, oxygen arterial pressure (PaO2), arterial pressure of carbon dioxide (PaCO2), and peripheral oxygen saturation (SpO2). The evaluation of respiratory mechanics was composed of static and dynamic compliance, airway resistance, and driving pressure. Results: A total of 78 patients were included, 58% of whom were males with a mean age of 55 ± 13 years. It was observed that there were no significant differences regarding respiratory mechanics, only the driving pressure presented statistical significance, the group 6 mL/kg was 8.3 ± 2.5 in the group 8 mL/kg 10.4 ± 2.1 presenting a value of (p < 0.001). Conclusion: Based on the findings of the present study, we conclude that different TVs do not significantly alter the blood gas variables and do not influence the respiratory mechanics of patients undergoing CS. How to cite this article: Cordeiro A, Souza A, de Brito Lima CR, Araújo J, Mascarenhas H, Guimarães A. Analysis of Different Tidal Volumes on Ventilatory Mechanics and Arterial Blood Gas Variables in Patients Undergoing Cardiac Surgery. Indian J Crit Care Med 2023;27(12):930-933.