EFFECT OF DIFFERENT VENTILATORY MODES ON HEMODYNAMIC AND CARDIAC FUNCTIONS DURING LAPAROSCOPIC OBESITY SURGERY: PP.8.313

Background: The potential clinical benefits of pressure-controlled ventilation (PCV) over volume-controlled ventilation (VCV) in patients undergoing laparoscopic obesity surgery still remain debated. PCV was thought to cause many deleterious hemodynamic effects, but recent studies indicate that PCV mode of ventilation does not cause adverse effects but also there are good systolic and diastolic functions and oxygenation during this mode. Methods: We studied thirty patients of both sexes, undergoing elective laparoscopic gastric banding obesity surgery with different risk factors for CAD, aged between 31–48 years. We ventilated all patients with two different ventilatory modes, pressure controlled ventilation (PCV) and volume controlled ventilation (VCV). We applied each mode of ventilation for 30 min. At the end of which, we recorded hemodynamic parameters, systolic and diastolic functions of the heart, using Trans Esophageal Echocardiography (TEE). Results: There was a significant increase in HR (P < 0.05) during PCV mode of ventilation more than VCV. Ejection fraction (EF), Fractional shortening (FS) and stroke volume (SV) were significantly increased while LVESD and ESV were significantly decreased during PCV. These results indicate improvement of left ventricular systolic performance during PCV in comparison to VCV mode. In addition, we found a significant reduction in A-wave and an increase, in E/A ratio, with PCV. Also, isovolumetric relaxation time (IVRT) was significantly increased during VCV. These results indicate impairment of left ventricular diastolic function during VCV in comparison to PCV mode. Oxygenation index was significantly increased while peak inspiratory pressure (PIP) was significantly decreased during PCV in comparison to VCV (P < 0.05). Conclusion: We concluded that there was an improvement of left ventricular systolic performance during PCV, in comparison to VCV mode. This achieves adequate tissue perfusion and oxygen delivery to meet cellular, metabolic needs which are essential goals in high risk, obese patients.