title: Significance of the whole blood activated clotting time in cardiopulmonary bypass.
abstract: Recent publications have described a poor correlation between whole blood activated clotting time (WBACT) values and plasma heparin levels during cardiopulmonary bypass (CPB). A prospective, controlled study was undertaken to investigate the variables which may influence the WBACT in this situation. Antithrombin III levels over a range of 35-93 u/dl did not influence either the WBACT value or plasma heparin level. However, reduced platelet function following infusion of prostacyclin (10 ng/kg/min prior to CPB and 20 ng/kg/min thereafter); platelet number (range 63-287 X 10(9)/l) and packed cell volume (range 16-30%) were found to correlate with the WBACT. It is concluded that in addition to the circulating plasma heparin level, the wide variations in platelet number, platelet function and packed cell volume which are frequently observed during cardiopulmonary bypass may also influence the WBACT value.
mesh_terms: D000328:Adult; D000368:Aged; D000990:Antithrombin III / Q000097:blood; D001780:Blood Coagulation Tests; D002315:Cardiopulmonary Bypass; D005260:Female; D006400:Hematocrit; D006493:Heparin / Q000097:blood; D006801:Humans; D007430:Intraoperative Care; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D010976:Platelet Count; D010979:Platelet Function Tests; D011446:Prospective Studies; D014914:Whole Blood Coagulation Time
chemical_list: D000990:Antithrombin III; D006493:Heparin