Background Venous thromboembolism (VTE) is becoming increasingly recognised in children’s healthcare despite being relatively uncommon in comparison to the adult population.^1,2 The incomplete haemostatic system that is present at birth responds with different pharmacokinetics and pharmacodynamics to anticoagulation therapy using low molecular weight heparins (LMWHs) in comparison to adults.³ It is not clear from what age adult dosing can be applied however this is thought to be around 16–18 years. Currently no comprehensive local guidelines are available for the prescribing and monitoring of enoxaparin in paediatric patients. Due to the increasing use of enoxaparin, there is a need to develop local guidelines for both prophylaxis and therapeutic treatment.

Aim To audit prescribing and monitoring of enoxaparin within the Children’s Hospital prior to the development of comprehensive local guidelines.

Method Retrospective and concurrent methods were used to collect data from all paediatric patients prescribed enoxaparin between the 1 st January 2015 and the 31 st January 2016. A range of computer systems, including ePrescribing records, an electronic results server and electronic and paper based notes were used to investigate each patient identified. Data was collected regarding enoxaparin indication, dosing and anti-Xa levels with data being entered into the audit tool.

Results 71% (n=17) of therapeutic treatment enoxaparin prescriptions were dosed according to the BNFc with no documentation found to justify alternative dosing regimens. 35% of patients had an anti-Xa level taken within 36 hours of therapeutic treatment initiation. 71% of levels (n=17) were taken 4–6 hours post dose. Where levels were found not to be in range, 82% of patients (n=11) had their dose adjusted. 56% (n=9) of patients then went on to have their anti-Xa level re-checked within 24 hours of dose change. 76% (n=25) of prophylactic enoxaparin prescriptions were dosed according to the BNFc. 93% (n=42) of all enoxaparin prescriptions were dosed as whole numbers.

Conclusion The results indicate that prescribers may benefit from having access to clear dosing and monitoring guidelines, to help improve the prescribing and monitoring in paediatric patients prescribed enoxaparin for both prophylaxis and therapeutic treatment of venous thromboembolism. The guidelines should contain details of dosing, monitoring, and how to adjust levels when necessary. Practice should be re-audited 12 months after the guidelines are published.

One limitation was the difficulty ascertaining the indication for treatment due to inadequate documentation.

References

1. Chalmers E, Ganesen V, Liesner R, Maroo S, Nokes T, Saunders D, et al. Guideline on the investigation, management and prevention of venous thrombosis in children. British Journal of Haematology2011;154(2):196–207.

2. Payne J. Aspects of anticoagulation in children. British Journal of Haematology2010;150(3):259–277.

3. Guzzetta N, Miller B. Principles of hemostasis in children: Models and maturation. Paediatric Anaesthesia2010;21(1):3–9.