Isovolumische Hämofiltration während und nach extrakorporaler Zirkulation kann die kardiopulmonale Funktion nicht verbessern.

Objective Inflammatory responses and tissue fluid accumulation after cardiopulmonary bypass (CPB) and myocardial ischemia/reperfusion can impair organ function. Hemofiltration (HF) may improve post-pump cardiac and pulmonary function by eliminating inflammatory mediators and fluids. The effect of HF without fluid removal was tested in a standardized model in healthy animals. Methods Twenty-six anesthetized pigs were subjected to crystalloid primed CPB (90 min cardioplegic cardiac arrest, 30 min reperfusion). HF was performed (n=13) during reperfusion and for 30 min post-CPB; filtered volume was replaced by Ringer’s lactate. Hemodynamic and pulmonary function as well as the systemic inflammatory response were assessed during 5h post-CPB. Postmortem myocardial and pulmonary water content was determined by gravimetry, myocardial samples were histologically examined for leukocyte infiltration. Results Following CPB, heart rate was increased, aortic pressure, cardiac output, and dP/dtmax were reduced in both groups. Alveolar-arterial oxygen difference was not affected in control animals, but was transiently increased by 34% after hemofiltration. Pulmonary shunt blood flow was not affected, pulmonary compliance was reduced by 10–15%, and pulmonary vascular resistance was doubled in both groups without intergroup differences. Postmortem left lung water content was 10% higher after hemofiltration compared to that of controls. Post-CPB elevation of plasma levels of TNF-a and IL-10 could be prevented by hemofiltration while myocardial leukocyte infiltration was not different between the two groups. Conclusions The present data confirm the adverse effects of CPB on cardiac and pulmonary function in a pig model, although organ dysfunction was discrete. Hemofiltration without fluid removal did not appear to affect organ function and could not diminish leukocyte infiltrates in the heart despite a documented reduction in inflammatory cytokines. This is in contrast to results in pediatric cardiac surgery, possibly due to the use of non-colloidal fluids for volume replacement. Thus, reduction of fluid load rather than elimination of inflammatory mediators appears to be the key factor by which hemofiltration can improve recovery following CPB