Performance Assessment of an Anti-Xa Assay-Based Heparin Dosing Protocol in Pediatric Patients on Extracorporeal Membrane Oxygenation

Introduction: The use of extracorporeal membrane oxygenation (ECMO) in the post-operative cardiac critical care setting is evolving. Anticoagulation monitoring is among the most challenging aspects of pediatrics. However, there is no consensus on the optimal dosing and monitoring of unfractionated heparin in this setting. To address this, we developed an anti-Xa assay-based protocol derived from the best available clinical and anecdotal evidence of use in ECMO therapy. Objective: To assess the performance of the protocol in achieving the anti-Xa assay therapeutic target. Methods: This prospective single-arm study was conducted in the Pediatric Cardiac Surgical Intensive Care Unit at a large tertiary hospital. We used two different anti-Xa assay intensity levels based on the patient’s bleeding status. Results: The median age was seven months (interquartile range [IQR]: 5–11.25), and the median weight was 5.7 kg (IQR: 3.8–13.82). The median ECMO duration was six days (IQR: 4.5–7.5). The bleeding protocol was used for most of the patients. Seventy percent achieved the anti-Xa assay therapeutic target during the study period (median: 75.5 hours; IQR: 60.5–117.5). Hemorrhagic complications were reported in 40 percent of the patients and thrombotic complications in 25 percent. The median hospital length of stay was 37 days (IQR: 22–43), with a discharge survival rate of 75 percent. Conclusion and Relevance: Despite a failure to achieve the anti-Xa assay target in the first ECMO days, most of our patients achieved the target by the median ECMO duration. Moreover, using two different anti-Xa assay levels reduced thrombotic complications in pediatrics.