Pulmonary blood flow and pressure as well as arterial blood oxygenation simulations in ventilated artificial patient supported by continuous rotary blood pump

Objectives: Our previous study suggested insignificant impairment of pulmonary circulation during artificial ventilation if the inspiration time is smaller than the duration of 2-3 heart cycles. This was due to pulmonary blood volume periodic changes. The aim of this study is to analyze the influence of left ventricular assistance by continuous rotary blood pump (RBP) on hemodynamic in ventilated, virtual patient. Methods: Virtual RBP was added to a previously elaborated hybrid (pneumonumerical), cardio-respiratory system adapted to simulate left heart failure. Ventilation to perfusion ratio (V/Q) in different lung regions as well as courses of pulmonary resistance (Rp) alteration, pulmonary blood flow (Qp) and pressure (Pp), alveolar partial pressure of oxygen and arterial blood oxygenation (SaO2) were analyzed for various parameters of mandatory ventilation and different RBP speeds (various RPM values). Results and Discussion: Experimental courses illustrate that RBP flow influences V/Q: the greater the Pp value because of low RBP flow, the smaller the influence of hydrostatic pressure on regional Rp. In particular, if the RBP blood flow is low, Rp is smaller because of increased Pp, and thus if the hypoxic vasoconstriction is not present, Qp through worse ventilated regions (the shunt) is greater causing a decrease in SaO2. If, however, the hypoxic vasoconstriction exists, results may be different. Conclusions: An artificial patient makes it possible to analyze complex multifactor problems, which would be impossible (because of both physical and ethical limitations) in cases of real patient examination.