Monitoring heparin and haemostasis during reconstruction of the abdominal aorta.
In spite of its unpredictable kinetics, heparin is still not generally monitored during peripheral vascular surgery. To evaluate heparin levels and neutralisation, plasma heparin concentrations were measured using a chromogenic substate method during 20 consecutive operations on the Abdominal Aorta. This was combined with measuring activated partial thromboplastin time (APTT), thrombin time (ThT), prothrombin time (PT), antithrombin-III (AT-III) and fibrinogen concentration. Heparin concentration 5 min after administration and the elimination rate showed a wide variation. Using a standard dosage for all patients resulted in plasma heparin levels that are potentially too low in some patients. The APTT and ThT were found to be unsuitable for an exact calculation of heparin levels. Protamine administration based on the surgeon's judgement of haemostasis was inadequate. Furthermore an intraoperative decrease of AT-III and fibrinogen was seen in eight patients. It is advisable and possible to have direct monitoring of heparin concentration during peripheral vascular surgery.
D001012:Aorta, Abdominal / Q000601:surgery*; D001780:Blood Coagulation Tests; D002863:Chromogenic Compounds; D006488:Hemostasis, Surgical; D006493:Heparin / Q000097:blood*; D006801:Humans; D007430:Intraoperative Care; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods
D002863:Chromogenic Compounds; D006493:Heparin