General
A man with renal failure, thrombocytopenia, and neurological symptoms. Normal PT/aPTT.
Thrombotic thrombocytopenic purpura (TTP) is a microangiopathic hemolytic anemia classically characterized by the pentad of fever, hemolytic anemia, thrombocytopenia, and renal and neurologic dysfunction.
Which bleeding disorder is associated with large platelets on peripheral smear and mucocutaneous bleeding, and does not correct with platelet transfusion?
Bernard-Soulier syndrome.
Which bleeding disorder is characterized by isolated thrombocytopenia with normal PT, aPTT, and coagulation factors, often following a viral illness?
Immune thrombocytopenic purpura (ITP).
Distinguishing between liver disease and disseminated intravascular coagulation may be challenging.
Measuring what factors can separate the 2 disorders in theory?
Measuring factor VIII levels (not affected by liver disease) and factor V levels (not consumed during intravascular coagulation) provides a theoretical means of separating the two disorders
Although measuring levels of factor VIII (normal in liver disease) and factor V (not consumed during intravascular coagulation) could theoretically distinguish coagulopathy of liver disease from disseminated intravascular coagulation, patients may have components of both disorders, and the management is usually analogous regardless of this distinction.
This factor is activated by tissue factor and begins the extrinsic pathway ?
factor VII
This symptom involves bleeding into joints, often seen in hemophilia .
Hemarthrosis
Condition of articular bleeding, that is into the joint cavity. This can occur after an injury or, more commonly, in bleeding disorders such as hemophilia. Patients will typically present with pain, swelling and a decreased range of motion of the involved joint.
The coagulation cascade was first fully described in this century.
20th century
Active bleeding in patients with coagulopathy of liver disease should be managed with
cryoprecipitate to maintain fibrinogen levels greater than 100 mg/dL (1 g/L) and platelet transfusions to achieve a platelet count greater than 75,000/µL (75 × 109/L).
Disseminated intravascular coagulation results from the simultaneous stimulation of
coagulation and fibrinolysis.
It is associated with severe sepsis, usually with septic shock; with disseminated malignancy, most classically with mucin-secreting pancreatic adenocarcinoma; and in pregnancy with various severe complications, including sepsis, placental abruption, and eclampsia.
Name the sequence of events in secondary hemostasis.
the activation of coagulation factors that eventually lead to fibrin clot formation. Clots are then degraded through fibrinolysis.
What antifibrinolytic medication helps reduce bleeding?
Tranexamic acid
The most common hereditary bleeding disorder, is caused by either deficiency or ineffectiveness of
Von Willebrand disease (vWD),vWF deficiency leads to mucocutaneous bleeding symptoms that mimic thrombocytopenia.
This pathology occurs in conditions of high circulatory shear stress like valvular heart disease, hypertrophic cardiomyopathy, circulatory assist devices, and extracorporeal membrane-oxygenation systems caused by excessive degradation of high-molecular-weight von Willebrand multimers by the proteolytic enzyme ADAMTS13
Acquired von Willebrand Disease
Affected patients develop bleeding conditions similar to those in hereditary vWD.
The prevalence of this disorder is likely to increase as more patients with severe cardiomyopathy are managed with left ventricular assist devices. These patients are routinely managed with warfarin and antiplatelet agents and have a significant incidence of gastrointestinal or other bleeding problems. Desmopressin and vWF concentrates have been used in management
Classic laboratory findings of disseminated intravascular coagulation
↓ Platelets, ↓ fibrinogen, ↑ D-dimer, ↑ PT/aPTT
This drug stimulates release of preformed von Willebrand factor and factor VIII, is used to treat minor bleeding in most patients with von Willebrand disease and is given prophylactically before surgery or procedures
Desmopressin
This is the most common non-infectious cause of transfusion-related death ?
Transfusion-related acute lung injury (TRALI) is a serious and potentially fatal complication of blood product transfusion in which a patient develops rapid onset lung injury and noncardiogenic pulmonary edema due to activation of immune cells in the lungs.
The scientist who was the first patient identified to have hemophilia B?
In 1952, Stephen Christmas, then a five-year-old boy, was diagnosed with a bleeding disorder that wasn't the previously known type of hemophilia (hemophilia A, or factor VIII deficiency). Researchers, Rosemary Biggs and Robert Gwyn Macfarlane, found that he lacked clotting factor IX, a different protein from the one missing in classic hemophilia.
Daily requirement of this vitamin comes from gut microflora (which may be destroyed by antibiotics); absorption requires biliary and pancreatic function
It acts as a cofactor for carboxylation and activation of certain coagulation factors & for the endogenous anticoagulants, protein C, and protein S.
Vitamin K
What organ produces most of the body’s clotting factors?
Liver
Patients with life-threatening illnesses characterized by systemic immune response syndrome with hypotension and multiorgan dysfunction are at risk for this pathology.
Disseminated Intravascular Coagulation
Normal PT, prolonged aPTT
Deficiency of factors VIII, IX, XI, or XII
von Willebrand disease (if severe and factor VIII level is quite low)
Heparin exposure
A common inherited clotting disorder in Caucasians.
Factor V Leiden deficiency
A 5-year-old child presents with gum bleeding and petechiae. Labs:
Platelet count: normal
PT/aPTT: normal
Platelet aggregation: abnormal with ADP, collagen, and epinephrine; normal with ristocetin.
Glanzmann thrombasthenia = defective GP IIb/IIIa → impaired platelet aggregation except with ristocetin
Which coagulation factors are vitamin K-dependent?
Factors II, VII, IX, X, and proteins C and S
Electrolyte abnormality caused by massive transfusion leading to muscle weakness or cardiac arrest.
hypocalcemia (from citrate toxicity)