Thorac Cardiovasc Surg 2015; 63(05): 397-403
DOI: 10.1055/s-0035-1554998
Original Cardiovascular
Georg Thieme Verlag KG Stuttgart · New York

Prolonged Activated Clotting Time after Protamine Administration Does Not Indicate Residual Heparinization after Cardiopulmonary Bypass in Pediatric Open Heart Surgery

Tomohiro Yamamoto
1   Department of Pediatric Anesthesiology and Critical Care Medicine, Asklepios Clinic Sankt Augustin, German Pediatric Heart Center, Sankt Augustin, Germany
,
Hans-Gerd Wolf
1   Department of Pediatric Anesthesiology and Critical Care Medicine, Asklepios Clinic Sankt Augustin, German Pediatric Heart Center, Sankt Augustin, Germany
,
Nicodème Sinzobahamvya
2   Department of Pediatric Cardiac Surgery, Asklepios Clinic Sankt Augustin, German Pediatric Heart Center, Sankt Augustin, Germany
,
Boulos Asfour
2   Department of Pediatric Cardiac Surgery, Asklepios Clinic Sankt Augustin, German Pediatric Heart Center, Sankt Augustin, Germany
,
Victor Hraska
2   Department of Pediatric Cardiac Surgery, Asklepios Clinic Sankt Augustin, German Pediatric Heart Center, Sankt Augustin, Germany
,
Ehrenfried Schindler
1   Department of Pediatric Anesthesiology and Critical Care Medicine, Asklepios Clinic Sankt Augustin, German Pediatric Heart Center, Sankt Augustin, Germany
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Publikationsverlauf

08. März 2015

20. April 2015

Publikationsdatum:
29. Juni 2015 (online)

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Abstract

Background In open heart surgery, heparinization is commonly neutralized using an empirical heparin:protamine ratio ranging between 1:1 and 1:1.5. However, these ratios may result in protamine overdose that should be avoided for its negative side effects on the coagulation system. This study aimed to indicate the appropriate treatment for prolonged activated clotting time (ACT) after protamine administration following cardiopulmonary bypass (CPB) in pediatric open heart surgery by investigating the underlying reasons for it.

Methods Twenty-seven children (<10 kg) undergoing open heart surgery were included. Heparin was administered only before CPB (400 IU/kg) and in the pump priming volume for CPB (2,000 IU) and was neutralized by 1:1 protamine after CPB. The blood heparin concentration was measured using anti-Xa assay. ACT and blood concentrations of heparin, coagulation factors, thrombin–antithrombin complex, and prothrombin fragment 1 + 2 were assessed. A rotational thromboelastometry (ROTEM; Tem International GmbH, München, Bayern, Germany) was used to confirm the coagulation status and residual heparin after protamine administration.

Results Anti-Xa assay showed that there is no residual heparin in the blood after 1:1 protamine administration. Nevertheless, ACT (128.89 ± 3.09 seconds before heparin administration) remained prolonged (177.14 ± 5.43 seconds at 10 minutes after protamine, 182.00 ± 5.90 seconds at 30 minutes after protamine). The blood concentrations of coagulation factors were significantly lower than those before heparin administration (p < 0.01). The low FIBTEM MCF of ROTEM (4.43 ± 0.32 mm) at 10 minutes after protamine indicated low fibrinogen concentration.

Conclusion Prolonged ACT after heparin neutralization by 1:1 protamine administration does not necessarily indicate residual heparin, but low blood concentrations of coagulation factors should be considered as a reason as well. Accordingly, supply of coagulation factors instead of additional protamine should be considered.

Note

This study was presented at the 2014 Annual Meeting of the European Association of Cardiothoracic Anesthesiologists (EACTA)/14th International Congress of Cardiovascular Anesthesia (ICCVA), Florence, Italy, September 17–19, 2014.