Monitoring of hemostasis and heparinization of neonates undergoing cardiac surgery (CS) using viscoelastic testing (VT) and standard laboratory test (SLT).

M. Lopez¹, P. Rossi², T. Vainstein², B. Diaz³, L. Barrera³, M. Martinuzzo⁴

¹Hematology and hemostasis division, Central Laboratory,Hospital Italiano de Buenos Aires, Argentina., Ciudad Autonoma de buenos aires, Ciudad Autonoma de Buenos Aires, Argentina, ²Anesthesia department, Hospital Italiano de Buenos Aires, Argentina., Ciudad Autónoma de Buenos Aires, Ciudad Autonoma de Buenos Aires, Argentina, ³Hematology and hemostasis division, Central Laboratory,Hospital Italiano de Buenos Aires, Argentina., Ciudad Autónoma de Buenos Aires, Ciudad Autonoma de Buenos Aires, Argentina, ⁴Hematology and hemostasis division, Central Laboratory,Hospital Italiano de Buenos Aires, Argentina., Ciudad Autonoma de Buenos Aires, Ciudad Autonoma de Buenos Aires, Argentina

Abstract Number: PB0242

Meeting: ISTH 2022 Congress

Theme: Pediatrics » Bleeding in Neonates and Children

Background: Adequate management of heparinization and hemostasis in neonates undergoing CS with cardiopulmonary bypass is challenging.

Aims: To track the effect of heparin and CS in neonates weighing < 5 kg using VT and SLT.

Methods: Neonates weighing < 5kg undergoing CS were included. Samples were obtained at the start of surgery (Basal), before separation from bypass (Bypass) and after heparin reversal (Postprotamine). VT performed by ROTEM delta (Instrumentation Laboratory , IL). SLT: PT% activity (PT%), APTT, thrombin time (TT), antithrombin (AT) and anti-factor Xa activity (AntiXa) by IL reagents in ACL TOP coagulometer. HemoCell CXH800 (Beckman Coulter) for PLT. Cumulative 12 hours chest tube drainage (CTD) was assessed for postsurgical bleeding.

Results: 32 patients were included. Median (IRQ) age was 19 days (6-25), median weight was 3380 gr (3082-3785). Bypass samples showed significantly prolonged EXTEM, INTEM and FIBTEM CFT and CT, as well as lower amplitude for A5, A10 and MCF when compared to Basal and Postprotamine.

PT% decreased, and APTT increased in Postprotamine compared to Basal.

PLT were lowest during bypass. Median basal AT was 0.56 IU/mL.

AntiXa median (IQR) was 5.3 (4.1-6.9) during Bypass. Postprotamine AntiXa was 0.1 (0.03-0.33), 9/32 patients with > 0.2 U/mL.

AntiXa correlated with EXTEM-CT and ACT during bypass, and with TT in Postprotamine. Postprotamine ACT correlated with PT, APTT, INTEM and HEPTEM CTs, and HEPTEM/INTEM CT ratio (table 1). Postprotamine AntiXa and ACT did not correlate.

HemoCell CXH800 (Beckman Coulter) for PLT.

Median CTD was 50 mL (28-91). CTD correlated with Postprotamine AntiXa and TT, and with total heparin dose administered (table 2).

Conclusion(s): ROTEM results were most affected during bypass, when hemodilution and consumption of procoagulant factors, fibrinogen and platelets are expected to occur.

AntiXa was the only test that tracked heparinization at all stages of surgery. Residual heparin measured by AntiXa correlated with postoperative bleeding.

Table 1

Correlations between SLT, ACT, AntiXa and ROTEM® parameters in the different surgical stages

Table 2

Correlation between initial heparin level used during surgery, total heparin level used and antiXa, ACT and postoperative bleeding

To cite this abstract in AMA style:

Lopez M, Rossi P, Vainstein T, Diaz B, Barrera L, Martinuzzo M. Monitoring of hemostasis and heparinization of neonates undergoing cardiac surgery (CS) using viscoelastic testing (VT) and standard laboratory test (SLT). [abstract]. https://abstracts.isth.org/abstract/monitoring-of-hemostasis-and-heparinization-of-neonates-undergoing-cardiac-surgery-cs-using-viscoelastic-testing-vt-and-standard-laboratory-test-slt/. Accessed September 22, 2023.

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