BACKGROUND: Expert opinion varies on the use of therapeutic unfractionated heparin during the peripartum period. While dosing guidelines have been suggested, their transition to clinical practice is lagging.
AIM: To evaluate the protocols employed, adherence to these protocols, and monitoring of therapeutic unfractionated heparin in obstetric patients during the peripartum period in a quaternary teaching hospital.
METHODS: This retrospective study investigated all women who received therapeutic heparin during the peripartum period between June 2014 and June 2016. The peripartum period was defined as 28 days prior to and post-delivery. Prescribing and administration information was obtained from the state-wide heparin infusion order form. Medical notes were studied to document the heparin infusion protocols utilised.
RESULTS: A variety of dosing approaches were used in the 20 patients studied. Heparin bolus dosing was correctly determined in 46% of results. Heparin infusion rate change was correctly determined in 64% of results. The APTT was correctly ordered by the medical officer in 230 results (66%), incorrectly ordered in 68 results (20%) and unable to make an interpretation in 48 results (14%). There were no cases of rethrombosis reported. Post-partum bleeding occurred in 2 patients. The APTT at the time of these bleeding events was noted to be subtherapeutic.
CONCLUSION: This study highlights the variability in therapeutic heparin protocols utilised during the peripartum period. The desire by clinicians to target a low APTT range during the postnatal peripartum period to balance bleeding risk has also been identified in this study.