Ultrafiltration during cardiopulmonary bypass: laboratory evaluation and initial clinical experience

Ultrafiltration during crystalloid hemodilution cardiopulmonary bypass (CPB) was evaluated in two groups of mongrel dogs: in one group during 2 hours of CPB with the heart empty and beating and in the other during 90 minutes of cold cardioplegic arrest followed by 30 minutes of recovery. In both groups, the accumulation of extravascular lung water was less in the dogs undergoing ultrafiltration than in control animals. In 10 patients with clinical evidence of severe fluid overload, ultrafiltration was employed during CPB. The amount of fluid removed ranged from 1,700 to 6,100 ml (mean, 3,240 +/- 1,481 ml [standard deviation]) and resulted in an average intraoperative fluid balance of -901 +/- 2,537 ml, a weight gain of 1.9 +/- 2.5 kg, and a decrease in extravascular lung water from 1,132 +/- 183 ml to 919 +/- 267 ml (p = 0.209). Ultrafiltration is a safe, effective means of removing body water and of preventing further accumulation of such water during hemodilution CPB.