This is a screening assay to aid in determining the risk for heparin induced thrombocytopenia (HIT).

Lt blue Sodium citrate (Na Cit) - 2.7mL

If the patient has a hematocrit >55, a specially prepared Lt blue Sodium citrate (NaCit) tube must be used in place of the standard Lt blue Sodium citrate (NaCit) tube.

Hematocrit-Anticoagulant adjustments

• Do not over or under fill tube as the ratio of anticoagulant to whole blood is critical

Coag – tube fill guidelines

• Immediately following collection, mix sample thoroughly by gentle inverting 8 - 10 times, to prevent clotting

• Process Platelet Poor Plasma (P.P.P)

  • Coag – how to prepare a specimen for special coagulation testing

• Transfer plasma into an aliquot tube using a spot label "NaCit Plasma P.P.P" to label as platelet poor plasma
• Freeze immediately

Microcentrifuge vial/tube in a Snap cap conical vial/tube and cap (Beaker sites)

Coagulation specimen transport vial/tube  (all other sites)

Frozen (strict)

Refrigerated - NO

• Specimen collected in Greiner tube(s)
• Improper labeling (unlabeled or mislabeled)
• Improper anticoagulant
• Improperly filled tube
• Hemolysis
• Clotted specimen
• Delay in transport
• Improper storage/transport temperature
• Patient on heparin > 1.0 IU/mL

Immunoturbidimetry

Negative

This is a screening assay. Results should be used in conjunction with other laboratory and clinical findings to aid in determining the risk for heparin induced thrombocytopenia (HIT). A negative result of testing for human platelet factor 4 (H/PF4) antibodies has about a 90% negative predictive value. Positive results may indicate the presence of heparin-associated antibodies but a positive result does not confirm the diagnosis of HIT. The serotonin release assay (SRA) remains the gold-standard test for confirmatory HIT diagnosis due to its high sensitivity and specificity.