title: Systemic heparinization during peripheral vascular surgery: thromboelastographic, activated coagulation time, and heparin titration monitoring.
abstract: Fifteen patients (9 male, 6 female) undergoing peripheral vascular surgery were monitored during surgery for evidence of subclinical anticoagulation using the activated coagulation time (ACT), thromboelastography (TEG), and heparin titration monitoring. Assessments were made at 30-minute intervals before and after the occlusion clamp. Mean (+/- SD) ACT values preoperatively were 111 (17) seconds, and 10 minutes after 5,000 IU of heparin, the ACT was 264 (57) seconds (P < 0.001). Intraoperatively, there was a significant decline in ACT values at 30 minutes (ACT 228 [50] sec, P < 0.005) and 60 minutes (200 [46] sec, P < 0.001) postheparin. No significant difference in ACT was observed between samples drawn distally and proximally to the clamp. TEG profiles were abolished in all patients immediately following heparinization. However, in 2 patients nearly complete return of the TEG coagulation profile was observed prior to the termination of the procedure and was associated with ACT values less than 160 seconds. The heparin device was unable to accurately monitor heparin elimination at these low doses. Variability of patient response to heparinization necessitates the use of intraoperative monitoring of anticoagulation during peripheral vascular surgery.
authors.affiliation: Department of Cardiothoracic Surgery, Killingbeck Hospital, Leeds, England.
authors.forename: P
authors.initials: P
authors.lastname: Martin
authors.forename: D
authors.initials: D
authors.lastname: Greenstein
authors.forename: N K
authors.initials: NK
authors.lastname: Gupta
authors.forename: D R
authors.initials: DR
authors.lastname: Walker
authors.forename: R C
authors.initials: RC
authors.lastname: Kester
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001018:Aortic Diseases / Q000601:surgery; D001157:Arterial Occlusive Diseases / Q000601:surgery*; D001777:Blood Coagulation / Q000187:drug effects; D001807:Blood Vessel Prosthesis; D005260:Female; D005263:Femoral Artery / Q000601:surgery; D005337:Fibrin / Q000096:biosynthesis; D006493:Heparin / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D006801:Humans; D007083:Iliac Artery / Q000601:surgery; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D016491:Peripheral Vascular Diseases / Q000601:surgery; D013916:Thrombelastography; D017186:Titrimetry; D014914:Whole Blood Coagulation Time
chemical_list: D005337:Fibrin; D006493:Heparin