The effects of modified hemofiltration on inflammatory mediators and cardiac performance in coronary artery bypass grafting

Cardiopulmonary bypass increases the blood levels of various immune mediato rs, thereby leading to a systemic inflammatory response syndrome, e.g. seps is, with some hemodynamic alterations, such as vasodilatation, tachycardia, and a decrease in systemic vascular resistance. Perioperative hemofiltrati on is one of the treatment modalities proposed to prevent this syndrome. Mo dified hemofiltration has been introduced recently by investigators who rec ommend that the former standard techniques are ineffective in eliminating t he inflammatory mediators. The purpose of this study was to determine the e ffects of the modified technique on these mediators and on hemodynamic para meters. Forty patients undergoing coronary artery bypass grafting were randomized i nto equal control and hemofiltered groups. The hemodynamic parameters, as w eil as blood samples, were taken before and after hemofiltration to assess blood concentrations of interleukin-6, interleukin-8 and neopterin. The hemodynamic parameters and immune mediator levels did not differ betwee n the two groups during the course of the study, except in the immediate po stoperative periods, where cardiac output, cardiac index, and systemic vasc ular resistance values were significantly greater in hemofiltered group whi le there were no differences in the immune mediators. The results of our st udy suggest that the effects of modified hemofiltration on immune mediators are stilt debatable. The improvement found in cardiac performance could be attributed to the prevention of hemodilution and hypervolemia.