Disorders Of Platelet And Vessel Wall Flashcards
Average life span of platelets
7-10 days
Order of Primary hemostasis and involved receptors
1) platelet adhesion (VWF, Gp1b)
2) platelet activation (Gp2b/3a)
3) platelet aggregation
An in vitro artifact resulting from platelet agglutination via antibodies when the calcium content is decreased by blood collection in EDTA (anticoagulant present in purple top used in CBC collection)
Pseudothrombocytopenia
Most common cause of thrombocytopenia
Drugs
Most patients develop heparin-induced thrombocytopenia (HIT) after exposure to heparin for how many days?
5-14 days
Most common complication of heparin-induced thrombocytopenia
Thrombosis
Characterized by mucocutaneous bleeding and a very low platelet count with normal peripheral blood cells and smear
ITP
Combined ITP and autoimmune hemolytic anemia
Evans’ syndrome
Pentad of findings in TTP
1) microangiopathic hemolytic anemia
2) thrombocytopenia
3) renal failure
4) neurologic findings
5) fever
Deficiency of metalloprotease ADAMTS13 which cleaves VWF, contributing to pathogenic platelet adhesion and aggregation
TTP
Mainstay of TTP treatment
Plasma exchange
Syndrome characterized by acute renal failure, microangiopathic hemolytic anemia, and thrombocytopenia; preceded by ep of diarrhea (E. Coli most frequent)
Hemolytic-Uremic Syndrome (HUS)
Mainstay of treatment for type 1 and 2 Von Willebrand Disease
Desmopressin (DDAVP)
Most common inherited bleeding disorder
Von Willebrand Disease
An inherited vessel wall disorder where abnormal telangiectatic capillaries result in frequent bleeding eps, primarily from the nose and GI tract
Osler-Weber-Rendu disease or Hereditary Hemorrhagic Telangiectasia (HHT)
