Impact of delayed systemic heparinization on postoperative bleeding and thromboembolism during post-cardiotomy extracorporeal membrane oxygenation in neonates

Abstract

Introduction: Veno-arterial extracorporeal membrane oxygenation is well-established for pediatric patients with post-cardiotomy heart failure. However, extracorporeal membrane oxygenation support is associated with major complications, that is, hemorrhage and thromboembolism. We seek to report our experience with delayed systemic heparinization during neonatal cardiac extracorporeal membrane oxygenation and its impact on bleeding and thromboembolism. Methods: We retrospectively identified 15 consecutive neonates who were placed on extracorporeal membrane oxygenation after congenital heart surgery during a period of 3 years (2015-2017). Our anticoagulation protocol consisted of full heparin reversal by protamine after switching from cardiopulmonary bypass to extracorporeal membrane oxygenation (target activated clotting time: 120 ± 20 seconds). Administration of systemic heparinization was delayed until postoperative drainage volume declined to <1 mL/kg/h. Primary study endpoints were thromboembolism, bleeding, and requirement of blood products on extracorporeal membrane oxygenation. Results: Our cohort (mean age: 13 ± 2.6 days; mean weight: 3.1 ± 0.3 kg; 66.7% male) required post-cardiotomy extracorporeal membrane oxygenation with a mean support time of 4.5 ± 2.2 days. Systemic heparinization was delayed averagely for 18.1 ± 9.3 hours. No thromboembolic events were observed on extracorporeal membrane oxygenation or after weaning. Relevant surgical site bleeding occurred in two patients (13.3%) requiring re-thoracotomy on the first postoperative day. Analysis of transfusion volumes revealed 24.5 ± 21.9 mL/kg/d mean packed red blood cells, 9.6 ± 7.1 mL/kg/d mean fresh frozen plasma, and 7.5 ± 5.7 mL/kg/d mean platelets. In-hospital survival was 86.6% (n = 13). Conclusion: In this retrospective analysis, the results of delayed systemic heparinization in neonatal post-cardiotomy extracorporeal membrane oxygenation could lead one to conclude that this routine is safe and favorable with low risk for thromboembolic events, reduced postoperative hemorrhage, and reduced blood product utilization.

Bleeding and thrombotic events in post-cardiotomy extracorporeal life support

“…Our centre has followed a similar approach, and we tend to delay heparinization even more in order to avoid haemorrhagic complications in patients on PC-ECLS. Von Stumm et al reported no increase in thromboembolic events and a potential reduction of bleeding events with delayed heparinization in neonatal patients on PC-ECLS [ 27 ].…”

Hemostatic complications and systemic heparinization in pediatric post-cardiotomy veno-arterial extracorporeal membrane oxygenation failed to wean from cardiopulmonary bypass

“…In a previous study, von Stumm et al (12) explored delayed systemic heparinization in 15 neonatal post-cardiotomy ECMOs for which the average UFH start time was 18.1±9.3 h. They found that delayed continuous UFH infusion could reduce bleeding and blood product transfusion without increased risk of thrombosis. This seems to be a bit different from our findings.…”

“…This high bleeding tendency leads to a clinical dilemma in choosing anticoagulation regimens, as there is no unified recommendation for practices related to peri-CPB unfractionated heparin (UFH) in pediatric VA-ECMO up until now (10,11). While some centers have adopted a strategy of delayed systemic heparinization (12), conclusions regarding its safety and practicability cannot be drawn due to insufficient patient numbers.…”

Utility of Routine Head Ultrasounds in Infants on Extracorporeal Life Support: When is it Safe to Stop Scanning?

“…4 In response to complications such as ICH and surgical site bleeding, efforts have been made to reduce the level of anticoagulation required, including the development of heparin-coated centrifugal pump systems allowing delayed initiation of anticoagulation, 12 and electing to delay anticoagulation when possible until chest tube drainage decreases in postoperative congenital cardiac patients. 8 In addition to these steps, frequent neuromonitoring is often performed, with common practice being to obtain daily HUS in infants on ECLS although the utility of this practice has been questioned. In a study of 30 infants who developed ICH on ECLS from 1996, 85% of all ICH occurred within 72 hours of ECLS initiation.…”

“…6,7 However, most of the research on this topic is now over 2 decades old, and there have been critical advancements and modifications in the management of patients on ECLS, such as reductions in anticoagulation target levels, with some patients undergoing anticoagulation-free trial periods following cannulation. 8 Furthermore, advances in ultrasound imaging technology and neonatal and pediatric critical care may have altered the prevalence and timing of ICH development and diagnosis in this patient population. It remains unknown if the advances over the past 2 decades have resulted in earlier detection of ICH in this population.…”