Background: CO2-gas insufflation is used for continuous de-airing during open heart surgery. The study aim was to evaluate if an additional separate venous reservoir eliminates CO2-insufflation induced hypercapnea and keeps sweep gas flow of the oxygenator constant.~Methods: A separate small reservoir are used during CPB in addition to a standard large venous reservoir. The small reservoir receive drained wound blood and CO2-gas continuously via a suction drain (1 L/min) and handheld suction devices from the open surgical wound. CO2-gas is insufflated via a gas-diffuser in the open surgical wound at 10 L/min. During cross-clamping, gas and blood are either continuously drained to the standard large venous reservoir or not, every 5 minutes after steady state of PaCO2 is observed, after adjustment of sweep gas flow as necessary. Mean values for each setup (2-4 times) for each patient will be analyzed with Wilcoxon rank-sum test.
The study aim was to evaluate if an additional separate venous reservoir eliminates CO2-insufflation induced hypercapnia and keeps sweep gas flow of the oxygenator constant during open heart surgery.