Should Standard On-Pump Protamine Dosing Formulas Be Recalculated for Off-Pump Coronary Artery Bypass Grafting?
Background: Since 1994 at the authors' institution, approximately 9000 cardiac surgical procedures were performed using activated clotting time (ACT)-monitored heparin anticoagulation for cardiopulmonary bypass and protamine administration calculated from a standard unchanged formula. This formula incorporates physiologic consequences of bypass pump-induced dilutional coagulopathy, platelet dysfunction, and coagulation/fibrinolytic cascade component activation, and thus may overcorrect in a subset of off-pump coronary artery bypass graft (OPCAB) patients who may in fact manifest a relative perioperative hypercoagulability state. This study evaluated a strategy of decreased protamine dosing in OPCAB.
Methods: Eighty consecutive OPCAB patients who underwent surgery performed by a single surgeon at a single institution over a 12-month period were retrospectively analyzed. Patients underwent a mean of 2.91 ± 0.1 OPCAB grafts with full heparinization and 50% of the calculated protamine dose was administered. ACT, partial thromboplastin times, thoracostomy tube outputs, transfusions, and clinical outcomes were assessed.
Results: Of 80 patients, 76 (95%) returned to baseline ACT values with 50% protamine dosing. All patients demonstrated intraoperative clinical evidence of hemostasis. Mean 8- and 24-hour thoracostomy tube outputs were 424 ± 24 mL and 806 ± 38 mL, respectively. A mean of 1.7 ± 0.2 packed red blood cell transfusions/patient was administered. There were no transfusions of platelets, fresh frozen plasma, or cryoprecipitate; no reexplorations; and no mortalities. Patients were discharged a mean of 4.4 ± 0.1 days postoperatively. Conclusion: A standard protamine dosing formula adequate for on-pump cardiac surgical procedures significantly overestimates protamine requirements for OPCAB. Patients treated with decreased protamine do not appear to have adverse outcomes.
Author Disclosure & Copyright Transfer Agreement
In order to publish the original work of another person(s), The Heart Surgery Forum® must receive an acknowledgment of the Author Agreement and Copyright Transfer Statement transferring to Forum Multimedia Publishing, L.L.C., a subsidiary of Carden Jennings Publishing Co., Ltd. the exclusive rights to print and distribute the author(s) work in all media forms. Failure to check Copyright Transfer agreement box below will delay publication of the manuscript.
A current form follows:
The author(s) hereby transfer(s), assign(s), or otherwise convey(s) all copyright ownership of the manuscript submitted to Forum Multimedia Publishing, LLC (Publisher). The copyright transfer covers the exclusive rights to reproduce and distribute the article and the material contained therein throughout the world in all languages and in all media of expression now known or later developed, including but not limited to reprints, photographic reproduction, microfilm, electronic data processing (including programming, storage, and transmission to other electronic data record(s), or any other reproductions of similar nature), and translations.
However, Publisher grants back to the author(s) the following:
- The right to make and distribute copies of all or part of this work for use of the author(s) in teaching;
- The right to use, after publication in The Heart Surgery Forum, all or part of the material from this work in a book by the author(s), or in a collection of work by the author(s);
- The royalty-free right to make copies of this work for internal distribution within the institution/company that employs the author(s) subject to the provisions below for a work-made-for-hire;
- The right to use figures and tables from this work, and up to 250 words of text, for any purpose;
- The right to make oral presentations of material from this work.
Publisher reserves the right to grant or refuse permission to third parties to republish all or part of the article or translations thereof. To republish, such third parties must obtain written permission from the Publisher. (This is in accordance with the Copyright Statute, United States Code, Title 17. Exception: If all authors were bona fide officers or employees of the U.S. Government at the time the paper was prepared, the work is a “work of the US Government” (prepared by an officer or employee of the US Government as part of official duties), and therefore is not subject to US copyright; such exception should be indicated on signature lines. If this work was prepared under US Government contract or grant, the US Government may reproduce, royalty-free, all or portions of this work and may authorize others to do so, for official US Government purposes only, if the US Government contract or grant so requires.
I have participated in the conception and design of this work and in the writing of the manuscript and take public responsibility for it. Neither this manuscript nor one with substantially similar content under my authorship has been published, has been submitted for publication elsewhere, or will be submitted for publication elsewhere while under consideration by The Heart Surgery Forum, except as described in an attachment. I have reviewed this manuscript (original version) and approve its submission. If I am listed above as corresponding author, I will provide all authors with information regarding this manuscript and will obtain their approval before submitting any revision. I attest to the validity, accuracy, and legitimacy of the content of the manuscript and understand that Publisher assumes no responsibility for the validity, accuracy, and legitimacy of its content. I warrant that this manuscript is original with me and that I have full power to make this Agreement. I warrant that it contains no matter that is libelous or otherwise unlawful or that invades individual privacy or infringes any copyright or other proprietary right. I agree to indemnify and hold Publisher harmless of and from any claim made against Publisher that relates to or arises out of the publication of the manuscript and agree that this indemnification shall include payment of all costs and expenses relating to the defense of any such claim, including all reasonable attorney’s fees.
I warrant that I have no financial interest in the drugs, devices, or procedures described in the manuscript (except as disclosed in the attached statement).
I state that the institutional Human Subjects Committee and/or the Ethics Committee approved the clinical protocol reported in this manuscript for the use of experimental techniques, drugs, or devices in human subjects and appropriate informed consent documents were utilized.
Furthermore, I state that any and all animals used for experimental purposes received humane care in USDA registered facilities in compliance with the “Principles of Laboratory Animal Care” formulated by the National Society for Medical Research and the “Guide for the Care and Use of Laboratory Animals” prepared by the Institute of Laboratory Animal Resources and published by the National Institutes of Health (NIH Publication No. 85-23, revised 1985).