ALTERATIONS IN HEMODYNAMICS AND LEFT-VENTRICULAR CONTRACTILITY DURINGCARBON-DIOXIDE PNEUMOPERITONEUM

Background: Carbon dioxide (CO2) pneumoperitoneum has been shown to ad versely affect hemodynamics in patients. This study specifically exami nes the potential contribution of altered left ventricular contractili ty (LVC) to hemodynamic changes observed during CO2 pneumoperitoneum. Methods: In a canine model, LV volumes, LV pressure, and intrathoracic and central venous pressures were recorded both at basal intra-abdomi nal pressure (IAP) and after CO2 insufflation to produce IAPs of 5-25 mmHg. Results: At IAPs greater than 15 mmHg, cardiac output and LV end -diastolic volume decreased. Mean arterial pressure and heart rate wer e unchanged. LVC, quantified using the linear Frank-Starling relations hip, was not affected by increases in IAP. Conclusions: This study is the first to quantify LVC during CO2 pneumoperitoneum and demonstrates no changes in contractility over IAPs from 5 to 25 mmHg. In the dog m odel, any hemodynamic alterations induced by CO2 pneumoperitoneum are secondary to altered LV preload and not alterations in contractility o r LV afterload.