clot retraction time

Indications: - evaluation of Glanzmann's thrombasthenia Normal range: 1) clot retraction begins in 1 hour 2) maximum clot retraction at 24 hours Clinical significance: 1) decreased retraction a) clinical disorders - thrombocytopenia (platelets < 100,000/mm³) - Glanzmann's thrombasthenia* - hyperfibrinogenemia - erythrocytosis b) pharmaceutical agents - plicamycin - carbenicillin * only platelet function disorder in which poor or absent clot retraction is suspected 2) normal clot retraction in: - Bernard Soulier syndrome - storage pool disease - cyclo-oxygenase inhibition (diminished thromboxane A2) Decreases: 1) clinical disorders a) thrombocytopenia (platelets < 100,000/mm³) b) Glanzmann's thrombasthenia c) hyperfibrinogenemia d) erythrocytosis 2) pharmaceutical agents a) plicamycin b) carbenicillin Specimen: 1) whole blood (no anticoagulant) 2) allow to clot at 37 degrees C in a clean glass tube

References

Clinical Guide to Laboratory Tests, 3rd ed. Teitz ed., W.B. Saunders, 1995