Experience of titrating enoxaparin dose to anti-Xa levels in paediatric burns


Paul Baker1, Victoria Lo1, Lindsay Damkat-Thomas1, Mohammad Nassimizadeh Richard Wong She1,
1Te Whatu Ora – Counties Manukau, Auckland New Zealand

Abstract

The rate of thrombosis has been reported as ranging from 0.053% to 6% in critically ill children. Acute thermal injury leads to a hypercoagulable state as well as a hypermetabolic state. Anticoagulation with low molecular weight heparin during the acute phase can prevent venous thromboembolism (VTE). Monitoring a patient’s response to Enoxaparin through measuring anti-Xa levels can guide individualised Enoxaparin dosing regimens.

At the National Burn Centre of New Zealand, we have been administering twice daily dosing of Enoxaparin titrated to ant-Xa levels in adults with major burn injury since 2019. In patients with major burns (TBSA >20%), anti-Xa levels are initially measured after the patient has received 3 doses of Enoxaparin. If the dose is adjusted, re-measuring the anti-Xa levels is required after 3 administrations at the new dose. Once stable levels have been reached, anti-Xa levels are rechecked once per week. Anti-Xa level monitoring continues whilst the patient is on Enoxaparin. Anti-Xa target ranges are 0.2-0.6 IU/ml for prophylactic anticoagulation and 0.6-1.0 IU/ml for therapeutic anticoagulation. Dose adjustments are discussed with Haematology, surgical and anaesthetic teams. We withhold morning doses when significant surgical intervention is planned, such as grafting.

We have had two major (>40% TBSA) paediatric burns in the past 6 months and present our experience of attempts to prevent thrombosis by titrating to anti-Xa. We used the established adult protocol and adjusted to our paediatric population. The journey and outcomes of both patients will be discussed.

Biography

Plastic Surgeon, current Burn Fellow at the NZ NBC