Kaolin-based activated coagulation time measured by sonoclot in patients undergoing cardiopulmonary bypass.
OBJECTIVE
In vivo data for the kaolin-based ACT test from the Sonoclot Analyzer (SkACT, Sienco Inc, Arvada, CO) are lacking. The aim of this study was to compare SkACT with an established kaolin-based ACT from Hemochron (HkACT) and anti-Xa activity in patients undergoing cardiopulmonary bypass (CPB).


METHODS
Prospective observational study.


METHODS
Community hospital.


METHODS
Fifty patients scheduled for elective cardiac surgery.


METHODS
Blood samples were taken before CPB at baseline (T0) and after heparinization (T1 and T2), on CPB after administration of aprotinin (5, 15, 30, 60 minutes; T3-T6), and at the end after protamine infusion (T7).


RESULTS
A total of 375 blood samples were analyzed. ACT measurements were comparable for SkACT and HkACT at each measurement time point. Overall bias +/- standard deviation between SkACT and HkACT was -19 +/- 75 seconds (-2.4% +/- 11.7%). Mean bias between SkACT and HkACT at each time point ranged from -35 to 3 seconds (-4.5% to 2.6%) and showed no statistical significance over time. Heparin sensitivity of SkACT and HkACT, defined as (ACT(Tx)-ACT(T0))/(anti-Xa(Tx)-anti-Xa(T0)), significantly increased for measurements during CPB (p < 0.001) but without significant difference between the 2 methods. Test variability was comparable for both ACT measurement techniques. Overall test variability was 7.5% +/- 7.4% for SkACT and 7.8% +/- 11% for HkACT.


CONCLUSIONS
Accuracy and performance of SkACT and HkACT were comparable for heparin monitoring in patients undergoing CPB for elective cardiac surgery. However, both tests were affected significantly after initiating CPB and aprotinin infusion.
Department of Anesthesia and Perioperative Care, University of California San Francisco, San Francisco, CA 94110, USA. mt.ganter@gmail.com
Michael T
MT
Ganter
Antoinette
A
Monn
Reza
R
Tavakoli
Richard
R
Klaghofer
Andreas
A
Zollinger
Christoph K
CK
Hofer
D000368:Aged; D000930:Antidiarrheals; D007611:Aprotinin / Q000494:pharmacology; D001777:Blood Coagulation / Q000187:drug effects / Q000502:physiology*; D002315:Cardiopulmonary Bypass / Q000379:methods*; D017558:Elective Surgical Procedures / Q000379:methods; D015951:Factor Xa / Q000378:metabolism; D065427:Factor Xa Inhibitors; D005260:Female; D006490:Hemostatics / Q000494:pharmacology; D006494:Heparin Antagonists / Q000008:administration & dosage; D006801:Humans; D007262:Infusions, Intravenous; D007431:Intraoperative Complications / Q000097:blood / Q000517:prevention & control; D007616:Kaolin; D008297:Male; D017202:Myocardial Ischemia / Q000097:blood / Q000601:surgery; D011183:Postoperative Complications / Q000097:blood / Q000517:prevention & control; D011446:Prospective Studies; D011479:Protamines / Q000008:administration & dosage; D013927:Thrombosis / Q000097:blood / Q000517:prevention & control; D016896:Treatment Outcome; D014914:Whole Blood Coagulation Time / Q000379:methods*
D000930:Antidiarrheals; D065427:Factor Xa Inhibitors; D006490:Hemostatics; D006494:Heparin Antagonists; D011479:Protamines; D007616:Kaolin; D007611:Aprotinin; D015951:Factor Xa