Fallibility of the platelet count and fibrinogen concentration in evaluating circulatory assistance technique--a plea...

Platelet and fibrinogen kinetics were investigated in calves undergoing prolonged extracorporeal left ventricular bypass in which both platelet and fibrinogen concentrations were within or above the normal range. Sequential survival time measurements documented significant continuing destruction of both platelets and fibrinogen during the course of these perfusions, with markedly elevated turnover rates of both components. The ineffectiveness of ASA and Persantine to return these functions to normal suggests that the mechanism of destruction includes trauma from the moving parts of the system, including the rotor and bearing seal, as well as surface-induced injury from the conduits and pump housing. Kinetic studies appear to be an essential requirement in the evaluation of blood destruction and subject tolerance of prolonged circuitry assistance devices.