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Performance Assessment of Anti-Xa Assay-Based Heparin Dosing Protocol in Pediatric Patients on Extracorporeal
Abdulrazaq S Al-Jazairi1, Eman M Shorog2,3, Tarek M Owaidah4
1Clinical Trials Transformation Initiative, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
Insights
This study developed an anti-Xa assay protocol for heparin monitoring in pediatric extracorporeal membrane oxygenation (ECMO) patients. The protocol successfully achieved therapeutic targets and reduced thrombotic complications.
Area of Science:
- Pediatric Critical Care Medicine
- Cardiovascular Surgery
- Pharmacology
Background:
- Extracorporeal membrane oxygenation (ECMO) use in pediatric cardiac critical care is expanding.
- Optimal unfractionated heparin dosing and monitoring remain challenging in pediatric ECMO.
- Lack of consensus necessitates novel monitoring strategies.
Purpose of the Study:
- To develop and assess an anti-Xa assay-based protocol for unfractionated heparin monitoring in pediatric ECMO.
- To evaluate the protocol's effectiveness in achieving therapeutic anti-Xa targets.
- To analyze the impact of the protocol on hemorrhagic and thrombotic complications.
Main Methods:
- Prospective single-arm study in a pediatric cardiac-surgery intensive care unit.
- Implementation of an anti-Xa assay-based heparin protocol with two intensity levels based on bleeding status.
- Monitoring of anti-Xa levels, bleeding, and thrombotic events.
Main Results:
- Seventy percent of patients achieved the anti-Xa assay therapeutic target.
- Median ECMO duration was 6 days, with 75% survival-to-discharge rate.
- Hemorrhagic complications occurred in 40%, thrombotic complications in 25%.
Conclusions:
- The anti-Xa assay protocol, despite initial delays, effectively achieved therapeutic targets by the median ECMO duration.
- Utilizing distinct anti-Xa assay levels for bleeding and non-bleeding patients helped mitigate thrombotic complications.
Background:
The use of extracorporeal membrane oxygenation (ECMO) in the postoperative 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 ECMO use and assessed its effectiveness in achieving the anti-Xa assay therapeutic target.
Methods:
This prospective single-arm study was conducted in the pediatric carcardiac-surgery intensive care unit of a large tertiary hospital. We used two different anti-Xa assay intensity levels based on the patients' bleeding status.
Results:
The median patient age was 7 (interquartile range [IQR]: 5-11.25) months, and the median weight was 5.7 (IQR: 3.8-13.82) kg. The median ECMO duration was 6 (IQR: 4.5-7.5) days. The bleeding protocol was used for most patients. Seventy percent achieved the anti-Xa assay therapeutic target during the study period (median: 75.5 h, IQR: 60.5-117.5 h). Hemorrhagic complications were reported in 40% of the patients, and thrombotic complications were reported in 25%. The median length of stay was 37 (IQR: 22-43) days, with a survival-to-discharge rate of 75%.
Conclusions:
Despite a failure to achieve the anti-Xa assay target within the first ECMO days, most patients achieved the target by the median ECMO duration. Moreover, using two different anti-Xa assay levels reduced thrombotic complications.
