Bleeding disorders Flashcards
In general, mucosal bleeding is suggestive of _____ or a defect in ______ while deep tissue bleeding is suggestive of a defect in _______
mucosal bleeding: thrombocytopenia, defect in platelets or vWF
Deep tissue bleeding: defect in coagulation cascade
von Willebrand disease is a _____ or _____ deficiency in vWF, usually with a parallel decrease in factor VIII function
qualitative or quantitative
The most common form of vWD is inherited in _______ manner and characterized by a quantitative decrease in vWF
autosomal dominant
If there is a significant disparity between vWF antigen and activity, this suggests a _______ defect in vWF
qualitative or functional defect, ie vWF type 2
How is type I vWD treated?
DDAVP: stimulates the release of endogenous vWF from endothelial cells
_______ contains a large amount of vWF and can be given in sever vWF deficiency
cryoprecipitate
Antifibrinolytic agents such as ______ or ____ can be useful for mucocutaneous bleeding in patients with vWD
amicar or tranexamic acid
Congenital deficiency of the __________ is known as Glanzmanns thrombasthenia
GpIIb/IIIa complex
characterized by deficient platelet aggregation in response to agonists
Congenital deficiency of ______ is known as Bernard-Soulier syndrome
GpIb
results in platelets with defective vWF dependent adhesion, usually mild thrombocytopenia with large circulating platelets
List diseases associated with decreased production of platelets
bone marrow disorders ex leukemia MDS aplastic anemia cytotoxic drugs viral infection nutritional deficiency marrow fibrosis
List three diseases associated with increased platelet utilization or destruction
immune mediated: ITP
non-immune mediated: DIC, TTP
What is the mechanism of ITP?
autoimmune destruction of platelets with normal or increased platelet production
usually antibodies against GpIb or GpIIb/IIIa, leads to platelet destruction in the spleen
Distinguish between ITP in children vs adults
In children, usually acute form due to infection and resolves spontaneously
In adults, more likely to be chronic and relapsing
In pregnant women with ITP, IgG can cross the placenta and occasionally cause:
neonatal thrombocytopenia
What agents are used to treat ITP?
glucocorticoids, IVIG, splenectomy, rituximab
new agents: eltrombopag and romiplostim are TPO agonists, stimulate platelet production
What drugs most commonly cause drug induced immune thrombocytopenia
antibiotics, quinine
What two conditions are associated with microangiopathic hemolytic anemia?
TTP: deficiency of ADAMTS-13, results in deposition of vWF thrombi in blood vessels leading to microangiopathy
HUS: kidneys are predominant organ affected, shiga toxin triggers endothelial injury leading to microangiopathy
_____ and drugs like NSAIDS and aspirin are associated with acquired defects in platelet function
uremia
List four causes of thrombocytosis
reactive- infection or trauma
myeloproliferative disorder
post-splenectomy or asplenia
iron deficiency
Newborns are vulnerable to bleeding due to _______ deficiency
vitamin K
Sever liver disease causes decreased synthesis of fibrinogen, prothrombin, factors _____________. Bleeding can be treated with replacement therapy with ______
Factors V, VII, IX, X, XI
treat with fresh frozen plasma
DIC is a syndrome in which ____ and _____ are generated at a rate that exceeds the ability of their natural inhibitors to neutralize them
thrombin (inhibitor is antithrombin)
plasmin (inhibitor is a-2- antiplasmin)
DIC is a syndrome that can be associated with:
infection tumors, esp adenocarcinoma leukemia obstetric complications hemolytic transfusion reactions liver disease trauma shock surgery
DIC involves diffuse endothelial injury. List laboratory findings in DIC
thrombocytopenia Prolonged PT/INR and aPTT Elevated FDP and D dimer Decreased fibrinogen Red cell fragmentation on blood smear
