BL.2.11. Hemostasis/Thrombosis Cases Flashcards
List important aspects of the patient history to ask when evaluating a patient with excessive bleeding or suspected thromboembolism.
Does pt display excessive, prolonged, recurrent, delayed bleeding?Did they have a reason to bleed excessively (trauma, surgery)?Is there a family history of significant bleeding?Heavy period: how many times a day she has to change? Clots w/ period? Severity?Any other history and symptoms of bleeding?Any history of transfusions? Iron replacement?
List important aspects of the physical exam when evaluating a patient with excessive bleeding or suspected thromboembolism.
Appearance, vitals, edema, heart sounds, hepatosplenomegaly, guiac check, neurologic function, conjunctivae, skin (petichiae etc.), adenopathy, distress, O2 sat, cyanosis
What laboratory studies are important in the diagnosis of vWD?
The normal ones: PTT, CBC, Diff, PT, TT, PFAvWF specific tests: Factor VIII activity, multimers, antigens, blood group typing, vWF ristocetin cofactor activity
What are some treatment options for patients with vWD?
If excessive menstrual bleeding, oral contraceptives will help.If bleeding is severe, or pre-surgery, can give desmopressin (DDAVP) IV or intranasally. This induces release of vWF and Factor VIII from endothelial cells.The next option is factor concentrate (Humate-P) containing vWF and Factor 8.Finally, cryoprecipitate can be given, but is not preferred due to risk of transfusion transmitted disease.
What is ITP? Please differentiate between primary and secondary, and acute and chronic.
Idiopathic thrombocytopenic purpura: platelet destruction due to creation of anti-platelet antibodies and destruction by WBCs.Primary: adults, children, pregnant women- diagnosis of exclusionSecondary: SLE, autoimmune diseases, lymphoproliferative diseases, immunodeficiency, viral infections, drug related thrombocytopeniaAcute: typically in children following viral infection, self limitedChronic: lasts >6mo, commonly seen in adults
What are some causes for secondary ITP?
Immune diseases: SLE, autoimmune diseases, lymphoproliferative diseases, immunodeficiency, viral infections, drug related thrombocytopenia
What is the typical bone marrow appearance in patients with ITP?
Normocellular with increased number of megakaryocytes: increased destruction of platelets and bone marrow can’t keep up
What types of bleeding are seen with ITP?
Bleeding can be mild to severe, characterized by petechiae, skin and mucous membrane bleeding, menorrhagia, GI hemorrhage, and in up to 1% of cases, intracranial hemorrhage
What is the platelet count at which risk for spontaneous bleeding with ITP increases?
<10-20 * 10^9/L
What options are available to treat emergent patients with ITP?
Non emergent patients: steroids (prednisone), IVIG, splenectomy, rituximab (depletes B cells)Emergent patients: if intracranial hemorrhage or hemorrhagic emergency: platelet transfusionAlso, avoid platelet function inhibiting drugs (ibuprofen, aspirin, plavix)
Why is platelet transfusion generally not indicated in patients with ITP?
Because they will rapidly destroy them with their antibodies.
What are some signs and symptoms for DVT and PE?
Nonspecific presentation. Anything from asymptomatic to sudden dyspnea, hypoxemia, pleuritic pain, hemoptysis, substernal pressure.
What are the risk factors for development of DVT and PE?
inactivity/stasis, stasis post surgery, estrogen use, smoking, hypercoaguable state (cancer or factor 5 leiden).
Why do you use D-dimer as a screening test for DVT and PE?
The cross linked fibrin degradation product is an indication that thrombosis is occuring, and that the blood clot is being dissolved by plasmin.
What are commonly used methods for diagnosing DVT and PE?
DVT: ultrasound of the legPE: ventilation/perfusion lung scans or by spiral CT or MRI.
