High volume hemofiltration improves right ventricular function in endotoxin-induced shock in the pig

This study assessed the influence of continuous high volume hemofiltration on right ventricular function of pigs with endotoxin induced shock. Eighteen anesthetized and ventilated pigs were studied for 240 min after the start of infusion of 0.5 mg/kg endotoxin over 30 min. Right ventricular ejection fraction (RVEF) was measured by rapid response thermodilution technique. After endotoxin infusion, the pigs were randomly divided into 3 groups: group 1 as a control group, receiving endotoxin only, group 2 to observe the effects of zero balance high volume veno-venous hemofiltration with removal of ultrafiltrate at a rate of 6000 ml/h, and group 3 to evaluate the effect of the extracorporeal circuit itself on RVEF. The decline of RVEF in group 2 was less than in group 1 (0.04 +/- 0.02 vs 0.21 +/- 0.03 (mean +/- SEM); p less than 0.001). The decline of RVEF in group 3 (0.24 +/- 0.02) was more pronounced than that in group 1 (p less than 0.05). The differences in the course of RVEF between group 1 and group 2 could not be explained by differences in heart rate, preload or afterload. Cardiac output and mean arterial pressure were significantly higher in group 2 than in group 1 (p less than 0.01). It is concluded that in this model, high volume hemofiltration improves RVEF and cardiac performance by removal of vasoactive mediators, responsible for myocardial depression.