1、危重患者血小板减少的诊治 四川省肿瘤医院ICU 刘真君 2017.4 1.概述血小板减少的定义、机制、诊断思路、常用的检查方法 2.危重患者中血小板减少的诊断和治疗 3.总结 4.病例讨论 血小板减少（thrombocytopenia）定义为各种遗传或获得性因素导致的血小板减少，血小板计数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%CI:
2、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,2008 Oct;30(5):408-14.血小板指数（platelet indices）
3、，包括MPV,血小板体积变异宽度（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 the hypoprolif
4、erative 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,specificity,positive prognostic valu
5、e,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。血小板指数的局限性在于血小板严重下降的患者（10 x 10(9)/L）结果有较大的偏差，输血等治疗措施影响对结果的判断。在ICU的应用价值需要再评估。Role of platelet volume indices in the differential diagnosis of thromboc
6、ytopenia:a simple and inexpensive method.Hematology(Amsterdam,Netherlands),2009 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 Haematol.2008;119(3):173-7.未成熟血小板比例和网织血小板比例 Gro
7、up 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 destruction 6.80%(12.20-21.39%)，16.14%(9.89-22.40%).(P 0.01).Group 3.Peripheral non-immune thrombocytopenia by abnormal distribution 9.04%(6.95-11.14%)，5.23%(3
8、.41-7.05%).Correlation between immature platelet fraction and reticulated platelets.Usefulness in the etiology diagnosis of thrombocytopenia.Eur J Haematol.2010 Aug;85(2):158-63.促血小板生成素（Thrombopoietin，TPO)在生成障碍患者，特别是再障患者明显升高，但在鉴别诊断中的价值有限。血小板相关抗体在免疫性血小板减少中有一定的价值，但检测方法的标准化和特异性需要再评估。Is the thrombopoiet
9、in 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 thrombocytopenia by combined use of two different platelet autoantibodie
10、s 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.以上是简易流程，最常见的几种疾病。针对住院特别是ICU患者情况可能更复杂，更多的是基础疾病和治疗性因素导致的血小板减少，医院获得性血小板减少（Hospital-acquired thrombocy
11、topenia）。Hospital-acquired thrombocytopenia.Hosp Pract(1995).2014 Oct;42(4):142-52.Thrombocytopenia in the intensive care unit patient.Hematology Am Soc Hematol Educ Program.2010;2010:135-43.Infection is a common cause of thrombocytopenia.Viral infections associated with thrombocytopenia include the
12、 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 thrombocytopenia are multiple and may include bone marrow suppression,peripheral
13、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 consists of treatment of the underlying infection and supportive care.1.感染 2 primary mech
14、anisms：decreased platelet production secondary to bone marrow suppression(eg,chemotherapeutic agents)and increased platelet destruction caused by drug-induced immune thrombocytopenia(DITP)后者更难以识别。2.药物诱导免疫性血小板减少 Drug-induced immune thrombocytopenia typically presents in a delayed fashion,5 to 10 days
15、 after initiation of the offending drug.There are 2 exceptions to this rule:(1)patients previously exposed to a drug（2）patients may develop thrombocytopenia immediately after initiation of a glycoprotein IIb/IIIa inhibitor(eg,eptifibatide,tirofiban,and abciximab)The following clinical criteria have
16、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 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的环境下，多种药物使用，合并多种疾病，可能难以判断。万古霉素 青霉素 哌拉西林 头孢曲松 甲氧苄氨嘧啶/磺胺甲恶唑
