Intraperitoneal heparin in CAPD.

In six patients on CAPD (continuous ambulatory peritoneal dialysis) the systemic effects of intraperitoneally administered heparin (5000 U) were investigated. Using a modification of a plasma heparin determination serial measurements of heparin concentration in dialysate were performed. During a dwell time of 4 hours the intraperitoneal heparin level decreased by 1825 +/- 253 U (mean +/- S.E.M.). Simultaneously the plasma anti-IIa-activity of heparin after 4 hours and the anti-Xa-activity after 2 and 4 hours increased significantly (p less than or equal to 0.05). The maximum of heparin activity after 4 hours was 0.015 +/- 0.001 U/ml and 0.024 +/- 0.003 U/ml, respectively (mean +/- S.E.M.). An increase of activated partial thromboplastin time was not observed. The small increase of heparin activity in plasma is in contrast to reported activities measured after subcutaneous application of this dose of heparin. In CAPD the effect of heparin is largely restricted to the peritoneal cavity.