Iloprost reduces procoagulant activity in the extracorporeal circuit.
Although activation of formed blood elements during cardiopulmonary bypass has been examined, its presumed procoagulant role has not been identified or quantified. We evaluated the effects of iloprost, an inhibitor of platelet and leukocyte function, on subclinical coagulation during simulated extracorporeal circulation. We determined that a heparin dose of 1 U/ml prevented clot formation in this model, but resulted in elevated plasma levels of fibrinopeptide A, the first cleavage product of fibrinogen. Human blood was recirculated with 1 U/ml heparin using a roller pump and pediatric reversed hollow fiber oxygenator (0.8 m2) for 2 hr at 37 degrees C. Iloprost (1 ng/ml, n = 5) reduced platelet adhesion, with platelet counts of 78 +/- 7% (mean +/- SEM) of baseline during 2 hr of simulated extracorporeal circulation, compared to 36 +/- 6% in control circuits (CONT: n = 6, P < 0.05). Plasma levels of platelet factor 4 and beta-thromboglobulin were also reduced by iloprost (486 +/- 116 ng/ml vs CONT, 2933 +/- 275 ng/ml, P < 0.05, and 938 +/- 274 ng/ml vs CONT, 5700 +/- 1109 ng/ml, P < 0.05, respectively). Circulating leukocyte counts were maintained in iloprost circuits (6.4 +/- 0.6 x 10(3)/mm3 vs CONT, 4.2 +/- 0.3 x 10(3)/mm3, P < 0.05), and neutrophil elastase levels rose to only 0.4 +/- 0.1 ng/ml in iloprost circuits, compared to 0.8 +/- 0.1 ng/ml in CONT (P < 0.05). Finally, iloprost treatment reduced fibrinopeptide A levels to 102 +/- 28 ng/ml (CONT, 793 +/- 337 ng/ml, P < 0.05) after 2 hr.(ABSTRACT TRUNCATED AT 250 WORDS)
Korn
R L
RL
Department of Surgery, Reichle Surgical Research Laboratories, Temple University Health Sciences Center, Philadelphia, Pennsylvania 19140.
Fisher
C A
CA
Stenach
N
N
Jeevanandam
V
V
Addonizio
V P
VP
D001777:Blood Coagulation / Q000187:drug effects*; D005112:Extracorporeal Circulation; D005344:Fibrinopeptide A / Q000378:metabolism; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D016285:Iloprost / Q000494:pharmacology*; D007958:Leukocyte Count; D019272:Leukocyte Elastase; D010196:Pancreatic Elastase / Q000097:blood; D015539:Platelet Activation / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects; D010976:Platelet Count; D010978:Platelet Factor 4 / Q000378:metabolism; D001620:beta-Thromboglobulin / Q000378:metabolism
D001620:beta-Thromboglobulin; D005344:Fibrinopeptide A; D010978:Platelet Factor 4; D006493:Heparin; D010196:Pancreatic Elastase; D019272:Leukocyte Elastase; D016285:Iloprost