This work was performed at the College of Veterinary Medicine, Athens, GA.
Sonoclot® Evaluation of Single- and Multiple-Dose Subcutaneous Unfractionated Heparin Therapy in Healthy Adult Dogs
Article first published online: 22 MAR 2012
Copyright © 2012 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 26, Issue 3, pages 631–638, May-June 2012
How to Cite
Babski, D.M., Brainard, B.M., Ralph, A.G., Pittman, J.R. and Koenig, A. (2012), Sonoclot® Evaluation of Single- and Multiple-Dose Subcutaneous Unfractionated Heparin Therapy in Healthy Adult Dogs. Journal of Veterinary Internal Medicine, 26: 631–638. doi: 10.1111/j.1939-1676.2012.00907.x
Portions of this work have been presented in abstract form at the International Veterinary Emergency and Critical Care Symposium 2010 (San Antonio, TX).
- Issue published online: 2 MAY 2012
- Article first published online: 22 MAR 2012
- Manuscript Accepted: 8 FEB 2012
- Manuscript Revised: 16 NOV 2011
- Manuscript Received: 26 AUG 2011
- Veterinary Emergency and Critical Care Foundation
- American College of Veterinary Emergency
- American College of Veterinary Emergency and Critical Care
- Viscoelastic coagulation monitoring
Heparin therapy is difficult to monitor due to variation in animal response. While laboratory measurements of activated partial thromboplasin time (aPTT) and Anti-Xa activity (AXA) accurately describe heparin effect, their availability is limited.
Sonoclot analysis would be as sensitive as AXA and aPTT to monitor effects of unfractionated heparin (UFH) in healthy adult dogs.
Six adult mixed-breed dogs.
A prospective study design was employed. On day 1, baseline samples were collected (CBC, PT, aPTT, and Sonoclot), and UFH (300 U/kg SC) was administered to 6 dogs following an IV loading dose of 50 U/kg. Sonoclot and aPTT were performed hourly for 12 hours. AXA was assayed at hours 3, 6, 9, and 12. UFH (300 U/kg q8 h SC) was administered at 12 hours, and subsequently (q8 h) for 2 additional days. On day 4, a final dose of UFH was administered, and a sampling protocol identical to day 1 was performed.
Sonoclot activated clotting time (ACT) and clot rate (CR) correlated with AXA (R = 0.69, R = 0.65, respectively, P < .001), although to a lesser degree than aPTT (R = 0.75, P < .001). Linear regression using ACT and CR as covariates indicated a stronger correlation with AXA (R = 0.73, P < .001). ACT values strongly correlated with aPTT (R = 0.87, P < .001).
Conclusions and Clinical Importance
Administration of UFH to healthy dogs results in progressive changes in Sonoclot values. AXA was correlated with a combination of ACT and CR and with aPTT. Sonoclot may play a role in monitoring UFH therapy; however, prospective studies evaluating its utility in clinical cases are warranted.