Optimization of Prime Fluid Strategy to Preserve Microcirculatory Perfusion During Cardiac Surgery With Cardiopulmonary Bypass, Part II

Acute microcirculatory perfusion disturbances is common in critical illness and associated with increased morbidity and mortality. Recent findings by our group showed that microcirculatory perfusion is disturbed during cardiac surgery with cardiopulmonary bypass (CPB) and remain disturbed up to 72 (seventy two) hours after surgery. A cardiopulmonary bypass is a machine which takes over heart and lung function, during the procedure. The disturbed microcirculation is associated with organ dysfunction induced by cardiac surgery using CPB, which is frequently seen (up to forty two percent, 42%) and results in a six-fold increase in mortality rate. The underlying cause of disturbed microcirculation is a higher endothelial permeability and vascular leakage and are a consequence of systemic inflammation, hemodilution (dilution of blood), hypothermia and hemolysis (breakdown of red blood cells). To gain the knowledge regarding disturbed microcirculation the investigators previously showed that hemodilution attributes to this disturbed perfusion. Hemodilution lowers colloid oncotic pressure (COP). Also, COP is affected by free hemoglobin, which increases with hemolysis and attributes to a disturbed microcirculation following CPB. This is interesting, as to the best of our knowledge, the effect of minimizing hemodilution and hemolysis during cardiac surgery on the microcirculatory perfusion has never been investigated, but could be the key factor in reducing organ dysfunction.