Is heparin therapy necessary in CAPD peritonitis?

OBJECTIVE

Heparin therapy in continuous ambulatory peritoneal dialysis (CAPD) peritonitis seems well established; it is costly due to the necessity of hospitalization. There are no clinical studies that show a benefit of such a treatment. The aim of this study was to investigate whether heparin therapy in CAPD peritonitis is necessary.

DESIGN AND PATIENTS

194 samples of peritoneal dialysates were collected from 17 patients over a period of 24 months. Samples were subdivided into three groups: those without peritonitis (< 100 leukocytes/microL), those with mild peritonitis (100-499 leukocytes/microL), and those with severe peritonitis (> or = 500 leukocytes/microL).

MEASUREMENTS

The number of leukocytes per microL dialysate and total protein concentrations were determined. Furthermore, dialysate concentrations of thrombin-antithrombin III- (TAT-) complexes (indicator of thrombin formation), D-dimers (indicator of fibrinolysis), and plasminogen activator inhibitor 1 (PAI-1) were measured.

RESULTS

The dialysate protein concentration progressively increased from no peritonitis to mild and severe inflammation. In parallel, dialysate TAT-complex and D-dimer concentrations increased. Thrombin-antithrombin III-complex and D-dimer concentrations correlated strongly in 179 cases (r = 0.76; 62 samples showing peritonitis, 117 samples with no evidence of peritonitis). In the remaining 15 samples of 3 patients, high PAI-1 levels (> 40 ng/mL) and low D-dimer concentrations were found. Eleven of the 15 samples showed evidence of peritonitis. In these 11 samples with evidence of peritonitis, high levels of TAT-complexes were detected, while D-dimer concentrations were found to be very low, pointing to a blocked fibrinolysis. The PAI-1 levels were not related to leukocyte counts or protein concentrations in the dialysates.

CONCLUSIONS

Based on our findings, the routine intraperitoneal administration of heparin in CAPD peritonitis is not necessary. In rare cases an imbalance between coagulation and fibrinolysis due to high PAI-1 levels exists (15 of 194 dialysate samples, 11 of the 15 samples showing peritonitis). These cases--which do require heparinization--can be identified by demonstrating low D-dimer levels in CAPD dialysate at times of peritonitis.