In vivo study of pulse conductance of oxygenators during pulsatile flow

Rationale: The objective of this clinical study is to endorse the hypothesis that oxygenators with a relatively high compliance and relatively low hydraulic resistance enable better pulse conductance than relatively stiff oxygenators featuring relatively high resistance.



Objective: Primary objective: measure pulse conductance of two standard types of oxygenators standard used during coronary artery bypass surgery using a standard heart-lung machine.

Secondary objective: measure/record the standard normalized index of haemolysis during elective coronary artery bypass surgery using a standard heart-lung machine.



Study design: prospective controlled randomized observational study



Study population: 40 patients undergoing elective coronary artery bypass grafting (CABG) using extracorporeal circulation.



Intervention (if applicable): no intervention, standard CABG procedure only



Main study parameters/endpoints: Pulse conductance of the oxygenator used during pulsatile perfusion with a standard heart-lung machine, and the normalized index of haemolysis measured in relation to the oxygenator used during pulsatile perfusion with a standard heart-lung machine.



Nature and extent of the burden and risks associated with participation, benefit and group relatedness: No other or additional risk than for those patients that do not involve in the study, and that undergo coronary artery bypass surgery. Differences in the two groups of standard oxygenators regarding primary and secondary objective is to be investigated. Both devices, however, have been clinically used for more than 15 years, and have been established as equivalent devices to take over lung function during heart surgery using extracorporeal circulation.



Regarding the results of the in vitro investigation in which the Quadrox had a better pulse conductance than the Capiox SX18, we expect a better pulse conductance in the Quadrox group in the clinical study as well. This would imply a less aggressive pulse generation in the Quadrox group, thus a reduced haemolysis. In standard clinical (non investigational) treatment, however, over the last 15 years, the haemolysis when using the Capiox SX18 oxygenator has not stood out. Therefore, we do not expect any complications in this group.

The objective of this clinical study is to endorse the hypothesis that oxygenators with a relatively high compliance and relatively low hydraulic resistance enable better pulse conductance than relatively stiff oxygenators featuring relatively high resistance.

Baseline measurement of free hemoglobin before initiation of cardiopulmonary bypass and after 30 min on cardiopulmonary bypass; continuous recording of line pressures after initiation of cardiopulmonary bypass.

Non-interventional study, therefore non-applicable