This study was conducted at the National Heart Institute and included 40 patients with valve replacement. The effects of certain modes of mechanical ventilation on hemodynamic parameters and oxygen transport were studied postoperatively to detect the best mode with favorable effects on the patients. These included: controlled mandatory ventilation (CMV), synchronized intermittent mandatory ventilation with pressure support ventilation (SIMV+PSV) and synchronized intermittent mandatory ventilation (SIMV). By comparing the hemodynamic variables using CMV mode and SINN + PSV mode, the latter showed significant reduction of cardiac index ( stroke volume index (SI) and significant elevation in left ventricular systolic work index (LVSWI). When oxygenation and ventilation parameters were compared. the SIMV + PSV mode showed significant elevation of static compliance (Cst), alveolo arterial oxygen difference (AaD02) and shunt fraction (Qs/ Qt) and significant reduction in dynamic compliance (Cdyn), oxygen availability index. (02AVI) and oxygen consumption index (V021). SIMV mode showed a significant elevation in hemodynamic parameters including CI. SI, mean pulmonary artery pressure (mPAP). pulmonary artery wedge pressure ( PAWP ), right cardiac work index (RCM) and right ventricular systolic work index (RVSVVI ) with significant decrease in left cardiac work inder (LCVVI) when compared to CMV mode and it showed a significant elevation in CI, SI. RCM and RVSW7 with |
