Unfractionated heparin: optimizing laboratory monitoring and reducing unwanted interference in everyday hemostasis test practice.

Unfractionated heparin (UFH) reflects a commonly used anticoagulant. UFH is widely utilised for a variety of reasons, including (i) to anticoagulate patients and help treat and/or prevent thrombosis, (ii) to maintain patency in artificial blood circuits, and (iii) to anticoagulate select blood samples collected for laboratory testing (typically for select biochemistry assays or blood gas analysis). As such, the presence of UFH is nearly ubiquitous in the hospital setting. In laboratory test practice, then, UFH may be purposely present in a sample destined for monitoring of patients on UFH therapy or for a biochemistry test, or else it may alternatively reflect an unwanted interference in other (hemostasis) laboratory tests. The purpose of this manuscript is to review UFH from the perspective of optimizing laboratory testing, meaning for both monitoring of UFH therapy, and alternatively to avoid or overcome unwanted interference in other laboratory tests.