醫(yī)學專業(yè)英語課件-3

1、Case DiscussionHuang HonghuiDepartment of HematologyRen Ji Hospital1Case Summary26 year-old, female patientpersistent nasal bleeding for one day, have an upper respi- ratory infection 2 weeks previously. No fever, chills, nausea, vomiting, abdominal pain, or joint pain.PE: multiple l-mm reddish spot

2、s on her lower extremities. No lymphadenopathy or hepatosplenomegaly.No excessive bleeding with menses, childbirth, prior epistaxis, easy bruisability, or bleeding into her joints.No family history of abnormal bleeding.Not take any medication.2Objects of AnalysisLearn the clinical approach to bleedi

3、ng disorders, specificly platelets disorders versus coagulation disorders.Learn about the differential diagnosis of thrombocytopenia, specifically thrombocytopenic purpura versus other platelet disorders, such as thrombotic thrombocytopenic purpura (TTP), hemolytic uremic syndrome (HUS), or dissemin

4、ated intravascular coagulation (DIC).Learn about the treatment of ITP.3Considerationsuperficial petechiae and mucosal bleeding disordered primarymary hemostasis laboratory testing complete blood countprothrombin time (PT) screeningpartial thromboplastin time (PTT) Bone marrow smear4APPROACH TO SUSPE

5、CTED THROMBOCYTOPENIA5HISTORYLiver disease, uremia, malignancy, systemic lupus erythematousMedications: over-the-counter products (aspirin)Family history of abnormal bleedingHistory of epistaxis, menorrhagia, excessive prolonged bleeding from minor cuts, bruising, prolonged or profuse bleeding after

6、 dental extraction, excessive bleeding after major surgery or obstetric delivery, trauma followed by bleeding considered excessive relative to the injury6Timing of BleedingIf bleeding following dental extraction is immediate and lasts for longer than 24 hours,a problem with primary hemostatic plug f

7、ormation may be present. Therefore, this may suggest a platelet disorder.If initial hemostasis seemed normal but prolonged bleeding developed 2-3 days later, a problem in the coagulation phase is suspected. 7Type of BleedingSpontaneous mucus membrane bleeding, such as gum bleeding, nose bleeding, an

8、d petechiae are suggestive of a vascular disorder, thrombocytopenia, or abnormal platelet function.Hemarthrosis, deep hematoma, and retroperitoneal bleeding are more likely to reflect a severe coagulation abnormality, such as hemophilia, if problems have been lifelongspontaneous inhibitor of factor

9、VIII, if problems appear later in iife. 8Vascular DisordersVascular purpura present with bleeding from mucus membranes and the appearance of petechiae but usually the platelet count and the coagulation profile (PT and PTT)are normalHereditary hemorrhagic telangiectasiasinherited as an autosomal trai

10、t of high penetrance.the most common hereditary vascular disorder The physical exam will show the presence of telangiectasias. 9Causes of thrombocytopenia decreased platelet productiondecreased platelet survivalsequestration (hypersplenism) dilutional10Spurious ThrombocytopeniaAutomated cell counter

11、s reports spurious thrombocytopenia in approximately 0.l% of patients.This is generally a result of platelet dumping after drawing blood into the anticoagulant ethylene diamine tetra acetate (EDTA) .ConfirmationIdentifying platelet aggregates on peripheral blood smearUsing citrate or heparin as an a

12、nticoagulant11Impaired platelet productionInfiltration caused by malignancy or myelofibrosisMarrow hypoplasiaChemicalsDrugsRadiationViruses12Decrease platelet survivalimmune thrombocytopenia purpua (caused by IgG antibody against the platelets),drug-induced thrombocytopenic purpurasecondary immunolo

13、gic purpura (as in lymphoma, lupus,infection with human immunodeficiency virus type 1)posttransfusion purpura.Disseminated intravascular coagulationhemolytic uremic syndromecavernous hemangiomaacute infections 13ITPAcute ITP early childhoodantecedent upper respiratory infectionself-limiting, usually

14、 resolves spontaneously within 3-6 months.Chronic ITPin adults, most likely to occur in women ages 20-40 years an insidious or subacute present.persist for months to Years, with uncommon spontaneous remission. 14Several immunologic disorders may mimic true ITP drug induced thrombocytopenic purpuraDi

15、scontinuation of the medication should lead to improvement in the platelet count within a time frame consistent with the drugs metabolism.Many drugs are blown to cause thrombocytopenic purpura, such as quinidine and quinine, Sulfonamide, heparin, and gold compounds. SLELymphomaLymphadenopathy spleno

16、megalyHIV-1 infectionPosttransfusion purpura15Nonimmunologic disorders may mimic true ITPDICTTP16DICETIOLOGYSecondary to some other process: sepsis, trauma, metastatic malignancy, obstetric causesCLINICAL COURSEcan be relatively mild indolent course, or severe llfe-threatening process;ongoing coagul

17、ation and fibrinolysis;can cause thrombosis or hemorrhage; consumption of coagulation factors is seen as prolonged PT and PTT17DICTREATMENTTreatment aimed at underlying cause.No proven specific treatment for the coagulation problem.If clotting,consider anticoagulate with heparin.If bleeding, replace

18、 factors and fibrinogen with fresh frozen plasma or cryoprecipitate.18TTPETIOLOGYMultiple causes, many seemingly trivial drugs/infection lead to endothelial injury and release of von Willebrand factor, triggering formation of mlcrovascular thrombi.CLINICAL COURSEfeveraltered mental statesthrombocyto

19、peniaMicroangiopathic hemolytic anemiaRenal failure19TTPTREATMENTPlasmapheresis (removal of the excess/abnormal vWF), most patients recovercorticosteroids20ITPETIOLOGYAntiplatelet antibody leading to platelet destructionCLINICAL COURSEChildren:following a Viral illness with resolution.Adults:a more

20、indolent course with progression and rarelys spontaneous resolution.Isolated thrombocytopenia, normal PT, PTT.Increased megakaryocytes on bone marrow aspiration.21ITPTREATMENTOral Corticosterolds,Splenectomy if resistant to steroids,ImmunosuppressantsIntravenous Immmoglobulin22AnswersMost likely dia

21、gnosis:Immune thrombocytopenic purpuraBest initial treatment:Oral corticosteroids23Comprehension QuestionsA 50-year-old man has been treated for rheumatoid arthritis for many years. He is currently taking corticosteroids for the disease.On examination, he has stigmata of rheumatoid arthritis and som

22、e fullness on his left upper abdomen. His platelet count is slightly low at 56,000/mm3. His WBC count is 3,100/mm3 and Hgb 9.Og/dL. Which of the following is the most likely etiology of the thrombocytopenia?A.Steroid inducedB.SequestrationC.Rheumatoid arthritis autoimmune induced D.Prior gold therap

23、y24Comprehension QuestionsA 30-year-old woman with ITP has been taking maximum corticosteroid doses and still has a platelet count of 20,000/mm3 and frequent bleeding episodes. Which of the following should she receive before her splenectomy?A.Washed leukocyte transfusion B.Intravenous interferon th

24、erapy C.pneumococcal vaccineD.Bone marrow radiotherapy25CLINICAL PEARLSBleeding abnormalities can be divided into primary hemostatic problems (platelet plug at time of injury)and secondary hemostasis (creation of a stable fibrin clot).Disorders of primary hemostasis (thrombocytopenia or von Willebrand) are characterized by mucosal bleeding and th