The efficiency of extracorporeal membrane oxygenation was studied for 2-3 hours in experiments on dogs with severe ventilatory respiratory failure. Extracorporeal oxygenation led to the decrease in arterial hypoxaemia and hypercapnia in animals. However, the variables did not reach the initial levels and were closer to normal values during veno-venous and not veno-arterial perfusion. During extracorporeal membrane oxygenation total systemic blood flow exceeded the initial level irrespective of the means of perfusion and total oxygen transport did not decline lower than the initial level. At the same time during veno-arterial perfusion oxygen delivery provided by the cardiac output decreased almost two-fold by the second hour of perfusion. This might be the reason for inadequate oxygen delivery to the brain and heart. 67% and 71% of animals survived after veno-arterial and veno-venous perfusion, respectively.

Functional and service characteristics of a Soviet membrane oxygenator are determined and compared with analogous foreign models. Results of hygienic examinations including medico-chemical and toxicological trials made it possible to evaluate oxygenator effects on a living organism.

Three modifications of a stationary membranous oxygenator (SMO) with utilization of new selective compositional membranes were developed. Test procedures for the SMO in the system gas-gas and gas-blood on a stand and in acute experiments on animals are described. The results obtained demonstrated that as concerns the transport of oxygen and carbon dioxide, as well as the stability in operation it is the model with the projections coincidently positioned on the upper and lower membranes whereby the peripheral blood is fed most efficiently.

Univariate diffusion of oxygen and carbon dioxide through a selective membrane of a stationary membranous oxygenator (SMO) and moving blood film is considered. Through the use of a precise exponential approximation of the oxyhemoglobin dissociation curve [S (p)=1--ae-bp] a partial oxygen pressure distribution [p (x)] along the SMO membrane and a transcedental equation for estimating the value for partial pressure (pa) of the arterialized blood and the SMO efficiency with reference to oxygen have been obtained. A somewhat less exact logarithmic approximation of the summary blood oxygen concentration [C1=a1+b1ln(p--po)] enables it to arrive at an analytical expression for calculating the SMO efficiency with reference to oxygen in a positively definite form. On the other hand, by using logarithmic approximation of the summary carbon dioxide concentration proceeding from the partial CO2 pressure in the blood a partial CO2 pressure distribution along the membrane, as well as an analytical expression for estimating the SMO efficiency with reference to carbon dioxide could be obtained.