危重患者血小板減少的診治ppt課件

1、危重患者血小板減少的診治四川省腫瘤醫(yī)院ICU劉真君2021.4.1.概述血小板減少的定義、機(jī)制、診斷思緒、常用的檢查方法2.危重患者中血小板減少的診斷和治療3.總結(jié)4.病例討論. 血小板減少thrombocytopenia 定義為各種遺傳或獲得性要素導(dǎo)致的血小板減少，血小板計數(shù)7.9 fl could predict hyperdestructive sensitivity of 82.3% (95% CI: 70.5-90.8), specificity of 92.5% (95% CI: 79.6-98.4), positive predictive value of 94.4% (95%

2、 CI: 84.6-98.8), negative predictive value of 77.1% (95% CI: 62.7-88.0) A prospective evaluation of normal mean platelet volume in discriminating hyperdestructive thrombocytopenia from hypoproductive 0thrombocytopenia.International journal of laboratory hematology,2021 Oct;30(5):408-14. 血小板指數(shù) platel

3、et indices，包括MPV, 血小板體積變異寬度platelet size deviation width ，PDW) 和大血小板比率 platelet-to-large-cell ratio ，P-LCR) The study group was divided into two categories: hypoproliferative and destructive thrombocytopenia All the three platelet indices were significantly higher in destructive group as compared to

4、 the hypoproliferative category. 134 thrombocytopenic patients (69 men, 65 women) who were divided into two groups group I (n = 63) included ITP patients group II (n = 71) included patients with HT due to myelosuppression secondary to chemotherapy Concerning MPV and PDW indices, sensitivity, specifi

5、city, positive prognostic value, negative prognostic value, efficiency and Youden index were 100% for the diagnosis of ITP. On the contrary, the values for P-LCR were significantly lower。. 血小板指數(shù)的局限性在于血小板嚴(yán)重下降的患者10 x 10(9)/L 結(jié)果有較大的偏向，輸血等治療措施影響對結(jié)果的判別。 在ICU的運(yùn)用價值需求再評價。 Role of platelet volume indices in

6、the differential diagnosis of thrombocytopenia: a simple and inexpensive method.Hematology (Amsterdam, Netherlands) ,2021 Jun;14(3):182-6. Increased values of mean platelet volume and platelet size deviation width may provide a safe positive diagnosis of idiopathic thrombocytopenic purpura.Acta Haem

7、atol. 2021;119(3):173-7. .未成熟血小板比例和網(wǎng)織血小板比例 Group 1. Central thrombocytopenia IPF 8.67% (6.49-10.46%) RP 4.08% (2.86- 5.30%) Group 2. Thrombocytopenia as a result of enhanced peripheral platelet destruction6.80% (12.20-21.39%) ，16.14% (9.89-22.40%). (P 0.01). Group 3. Peripheral non-immune thrombocyt

8、openia by abnormal distribution 9.04% (6.95-11.14%) ，5.23% (3.41-7.05%). Correlation between immature platelet fraction and reticulated platelets. Usefulness in the etiology diagnosis of thrombocytopenia.Eur J Haematol. 2021 Aug;85(2):158-63. 促血小板生成素Thrombopoietin ，TPO)在生成妨礙患者，特別是再障患者明顯升高，但在鑒別診斷中的價值

9、有限。 血小板相關(guān)抗體在免疫性血小板減少中有一定的價值，但檢測方法的規(guī)范化和特異性需求再評價。 Is the thrombopoietin assay useful for differential diagnosis of thrombocytopenia? Analysis of a cohort of 160 patients with thrombocytopenia and defined platelet life span.Clin Chem. 2001 Sep;47(9):1660-5. Attempt to improve the diagnosis of immune th

10、rombocytopenia by combined use of two different platelet autoantibodies assays (PAIgG and MACE).Haematologica. 2002 Oct;87(10):1046-52. Quantification of platelet-associated IgG for differential diagnosis of patients with thrombocytopenia.Thromb Haemost. 2000Nov;84(5):779-83. 以上是簡易流程，最常見的幾種疾病。針對住院特別

11、是ICU患者情況能夠更復(fù)雜，更多的是根底疾病和治療性要素導(dǎo)致的血小板減少，醫(yī)院獲得性血小板減少Hospital-acquired thrombocytopenia。 Hospital-acquired thrombocytopenia.Hosp Pract (1995). 2021 Oct;42(4):142-52. Thrombocytopenia in the intensive care unit patient.Hematology Am Soc Hematol Educ Program. 2021;2021:-43. . Infection is a common cause of

12、thrombocytopenia. Viral infections associated with thrombocytopenia include the human immunodeficiency virus, hepatitis C virus, and Epstein-Barr virus，cytomegalovirus Thrombocytopenia is also frequent in patients with bacterial infections and sepsis or severe sepsis. Mechanisms of infection-induced

13、 thrombocytopenia are multiple and may include bone marrow suppression, peripheral immune destruction, and activation and consumption. The fall in platelet count associated with sepsis is typically gradual, occurring over 5 to 7 days, and the thrombocytopenia is characteristically mild. Management c

14、onsists of treatment of the underlying infection and supportive care. 1.感染. 2 primary mechanisms ：decreased platelet production secondary to bone marrow suppression (eg, chemotherapeutic agents) and increased platelet destruction caused by drug-induced immune thrombocytopenia (DITP) 后者更難以識別。2.藥物誘導(dǎo)免疫

15、性血小板減少. Drug-induced immune thrombocytopenia typically presents in a delayed fashion, 5 to 10 days after initiation of the offending drug. There are 2 exceptions to this rule: (1) patients previously exposed to a drug 2patients may develop thrombocytopenia immediately after initiation of a glycoprot

16、ein IIb/IIIa inhibitor (eg, eptifibatide, tirofiban, and abciximab) . The following clinical criteria have been proposed to estimate the likelihood that a given drug is the cause of DITP: (1) thrombocytopenia occurs after exposure to the drug and improves after the drug is stopped; (2) the candidate

17、 drug is the only drug used before the onset of thrombocytopenia, or other drugs are continued or reintroduced without affecting the platelet count; (3) other causes of thrombocytopenia are excluded; (4) thrombocytopenia recurs if the drug is restarted 但在ICU的環(huán)境下，多種藥物運(yùn)用，合并多種疾病，能夠難以判別。 .萬古霉素青霉素哌拉西林頭孢曲

18、松甲氧芐氨嘧啶/磺胺甲惡唑利福平卡馬西平苯妥英丙戊酸阿昔單抗替羅非班依替巴肽奎寧對乙酰氨基酚布洛芬米氮平 雷尼替丁. Suspected DITP is treated by discontinuing the potentially offending drug. The platelet count typically begins to improve within 1 to 2 days after the drug is stopped .The median time to recovery of platelet count is 7 days. Patients with se

19、vere thrombocytopenia and bleeding may be treated with platelet transfusion. In particularly severe cases, corticosteroids, intravenous immunoglobulin, and plasma exchange have been used, although there is limited evidence of efficacy with these. Heparin-induced thrombocytopenia (HIT) is an immune-m

20、ediated disorder that occurs after exposure to unfractionated heparin or low molecular weight heparin. Unlike most other forms of DITP, HIT is generally prothrombotic rather than prohemorrhagic. Thrombotic complications, include deep venous thrombosis, pulmonary embolism, peripheral arterial thrombo

21、sis, ischemic stroke, and myocardial infarction.肝素誘導(dǎo)的血小板減少. an intermediate or high probability of HIT, heparin should be discontinued the patient should be treated with a nonheparin anticoagulantargatroban, danaparoid ，bivalirudin fondaparinux Once the platelet count has recovered, patients may be

22、transitioned to warfarin. . Disseminated intravascular coagulation (DIC) occurs not in isolation but secondary to an underlying disorder These conditions may generate procoagulant substances, leading to widespread activation of coagulation and deposition of fibrin in the microvasculature. The end re

23、sult is thrombosis of small vessels and end-organ ischemic injury. Accelerated consumption of coagulation factors and platelets may also produce a concomitant bleeding tendency3.彌散性血管內(nèi)凝血.DIC的病理生理機(jī)制. The cornerstone of therapy for DIC is treatment of the underlying condition. Transfusion is indicated

24、 in patients who are bleeding or otherwise at high risk for bleeding. Therapeutic heparin should be considered in patients with DIC complicated by overt thrombosis. Antifibrinolytic treatments are generally contraindicated in patients with DIC due to an increased risk of thrombosis. Thrombotic throm

25、bocytopenic purpura (TTP) is a thrombotic microangiopathy It is characterized by thrombocytopenia and microangiopathic hemolytic anemia and may also include neurologic symptoms, fevers, and renal impairment TTP is caused by a deficiency of ADAMTS13, a protease that cleaves von Willebrand factor. In

26、the absence of ADAMTS13, ultralarge von Willebrand factor multimers promote formation of platelet aggregates in the microvasculature, causing shear stress and mechanical fragmentation of erythrocytes in areas of high flow.4.血栓性血小板減少性紫癜.TTP患者肺栓塞病理TTP患者腎小球病變. Diagnosis of TTP is based on a combination

27、 of clinical signs and symptoms and laboratory values. The median platelet count at presentation is 10 to 30 109/L. The median hemoglobin is 8 to 10 g/dL and is accompanied by markers of intravascular hemolysis. Schistocytes, and often nucleated red cells, are found in the peripheral blood smear. Th

28、e PT and aPTT are typically normal, and the direct Coombs test is negative. Patients may have acute kidney injury or proteinuria. Thrombotic thrombocytopenic purpura is a medical emergency, and treatment of suspected TTP must be commenced immediately. daily plasma exchange (PEX) decreases mortality

29、rates from 80%90% to under 20%. plasma infusion while awaiting exchange therapy. Plasma exchange is continued until platelet count recovery. high-dose corticosteroids, which have been shown in some studies to improve outcomes. Rituximab, a monoclonal antibody that targets CD20 on B lymphocytes, is w

30、idely used in patients with refractory or relapsed disease. platelet transfusion is relatively contraindicated unless serious bleeding is present. Posttransfusion purpura (PTP) is a rare complication of blood transfusion that causes acute, severe thrombocytopenia with a median nadir platelet count , 10 109/L. occurs 5 to 10 days after transfusion caused by alloantibodies against a platelet antigen， allo