LOINC Code 73817-9: Percent heparin inhibition (S) [Ratio]

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Percent heparin inhibition. It is commonly used with the system or sample type Ser.

When is it used?

• Used in lab systems, EHRs, and clinical data exchange.
• May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
• Status: ACTIVE
• Order vs observation: Observation

What it does not mean

• The code identifies the observation or test, not the actual result.

Key facts

• Percent heparin inhibition [Ratio] in Serum
• Percent heparin inhibition
• The percent inhibition by heparin is determined by adding excess heparin (high-dose heparin) to the patient's serum. Testing is performed to increase the specificity of the assay and confirm a positive heparin induced antibody result. Inhibition of a positive result by 50% or more reduction in the optical density is considered confirmatory and characteristic of Type II heparin induced thrombocytopenia (HIT) antibodies.
• Hep; Hepar; Heparn; Point in time; Prcnt hep inhibited; QNT; Quan; Quant; Quantitative; Random; Ratios; Rto; Serology; Serum; SR

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Frequently asked questions