Correspondence  |   October 2015
In Reply
Author Notes
  • Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada (K.K.).
  • (Accepted for publication June 15, 2015.)
    (Accepted for publication June 15, 2015.)×
Article Information
Correspondence   |   October 2015
In Reply
Anesthesiology 10 2015, Vol.123, 975-976. doi:
Anesthesiology 10 2015, Vol.123, 975-976. doi:
We appreciate the letter by Bulatovic and Taneja on our study1  and agree that it would have been more accurate to state heparin dose in units rather than in milligrams in our algorithm. We also agree that heparin management, which encompasses heparin dosing, monitoring of effect, and reversal with protamine, is an important component of cardiac surgery that is incompletely understood and requires further investigation. Given that our algorithm was not aimed at optimizing or even modifying heparin management, we made no attempts to alter or audit heparin management practice. The milligram to milligram representation of the protamine to heparin dose is consistent with a low-dose protamine practice.2  Because heparin management at our institution was not altered with protocol implementation, this is not likely to have had an impact on our results.
Our algorithm was aimed at optimizing coagulation management by incorporation of point-of-care coagulation testing into routine practice, and the results suggest that we succeeded in reducing transfusions and some adverse outcomes. We are looking forward to the results of our large, multicenter study to see whether our findings are generalizable ( Identified NCT02200419).
Nevertheless, we do believe that additional benefits in coagulation management can be achieved by optimizing heparin management. We have noticed that in some of our patients who bleed unexpectedly, there is a profound deterioration in coagulation status, particularly platelet count and function, from rewarming to postprotamine periods, suggesting a contributory effect of protamine to the coagulopathy.3  Perhaps, these patients would not have bled if heparin management was optimized by, for example, using mathematical models4,5  or point-of-care heparin–protamine titration systems.6 
We therefore agree with Bulatovic and Taneja that systematic studies on heparin management in cardiac surgery are required, as we do not seem to be much ahead of where we were in the 1970s.7  Perhaps, with optimized heparin management, we can further improve hemostatic management of cardiac surgical patients and reduce the burden of perioperative coagulopathy.
Competing Interests
The authors have received research funding from Tem International GmBH (Munich, Germany) and Helena Laboratories (Beaumont, Texas), for an ongoing multicenter randomized trial of a point-of-care–based coagulation algorithm.
Keyvan Karkouti, M.D., Jeannie Callum, M.D., Vivek Rao, M.D., Ph.D., Stuart A. McCluskey, M.D., Ph.D. Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada (K.K.).
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