What constitutes adequate perfusion?

Success of a perfusion depends not as much on the perfusion system as how that system is applied. A bubble oxygenator system properly managed can be safely run for many hours. Perfusion rate alone is an inadequate criteria for conduct of an adequate perfusion. 75 to 100 cc/kilo/min. perfusion rate is recommended. Minimal mean arterial pressures (60-70 mmHg) are essential to maintain good function of all organ systems for many hours of perfusion and to avoid disseminated intravascular coagulation by keeping capillary beds open. Foreign blood (bank blood) should be avoided to a maximal degree as foreign blood along with hypotensive situations as with poor perfusions can increase predisposition to DIC and organ failure. Hypokalemia (plasma and intracellular) predisposes to poor peripheral resistance during perfusion and consequent low mean arterial pressures. Fifty to 150 meq. of potassium chloride injected into the perfusate is generally required. Excessively high pO2 (over 150) and/or excessively low pCO2 (under 35) may contribute to CNS aberrations. Cannula placement and size are important considerations as well as suction forces on the venous cannula due to hydrostatic pressure on the venous return line. This force must be varied at times for maximal return. The inferior canal catheter must be kept out of the hepatic veins.