假性血小板减少的原因分析及对策探讨

Discussion on causal analysis and countermeasures of pseudo thrombocytopenia

目的探讨血细胞分析仪导致假性血小板减少的原因,并提出预防对策。方法选择2016年1月—2017年9月云南省普洱市人民医院门诊及住院的68例首次仪器检测出现假性血小板减少的患者,积极查找检测过程中出现的原因,并采取相应措施进行纠正,然后进行复检,分析血细胞分析仪导致出现假性血小板减少的原因。结果 68例导致首检为假性血小板减少的原因中,有28例为乙二胺四乙酸依赖性血小板假性减少症(EDTA-PTCP),23例为标本采集不畅,17例为大血小板。与首次仪器检测结果比较,纠正后血小板计数(PLT)的复检结果均明显升高[PLT(×10~9/L):186±39比41±22、182±32比63±19、122±24比72±14,均P<0.05]。结论血细胞分析仪导致假性血小板减少的原因主要为EDTA-PTCP、标本采集不畅以及大血小板等。在进行血常规检测时,若出现血小板显著减少、仪器报警血小板聚集、直方图异常等,且患者无瘀点或瘀斑等出血情况,临床应该高度怀疑是EDTA-PTCP。可采用血涂片镜检观察血小板的数量和形态以及是否有血小板聚集;同时请患者至检验科直接采血以缩短检测时间,并更换抗凝剂重新进行检测;若结果仍然无法纠正,则应该采用手工稀释计数法以得到准确的检验数据,协助临床医生对患者的疾病做出正确的诊断,防止误诊误治。

Objective To explore the reasons of hematology analyzer leading to pseudo thrombocytopenia（PTCP） and put forward preventive measures. Methods From January 2016 to September 2017, 68 inpatients and outpatients with PTCP turning up after the first time of examination by hematology analyzer in Pu＇er People＇s Hospital of Yunnan Province were carefully investigated concerning the causes leading to PTCP in the process of detection, and corresponding measures were adopted for rectification, then the platelet count was rechecked by the instrument. Results In the causes of 68 cases with PTCP appearing after the first time of examination by hematology analyzer, there were 28 cases induced by ethylenediamine tetra-acetic acid（EDTA） called EDTA dependent PTCP（EDTA-PTCP）, 23 patients due to troubles in specimen collection and 17 patients due to large platelets. Compared with the first results of instrumental detection, after the errors were corrected, the retested results of platelet count（PLT） were significantly higher [PLT（×10~9/L）： 186±39 vs. 41±22, 182±32 vs. 63±19, 122±24 vs. 72±14, all P 〈0.05]. Conclusion The main causes of PTCP related to hematology analyzer detection in this study are associated with EDTA-PTCP, specimen collection troubles and large platelets, etc. In the process of complete blood count with an analyzer, if a patient presents a significant platelet count reduction, abnormal histogram, or an alarm of platelet aggregation, etc., meanwhile, if the patient has no sign of petechia, ecchymosis and other bleeding situations, clinically, it should be highly suspected of EDTA-PTCP. Blood smear microscopy can be used to observe the number, morphology and presence or absence of aggregation of platelets; in the mean time, the patient should be instructed to go to the laboratory to collect blood and perform the test immediately to shorten the test time, the anticoagulant is replaced and the test should be performed again; if the result is still in doubt, manual platelet counting should be carried out to obtain an accurate result to help clinicians make correct diagnosis and avoid misdiagnosis and mistreatment.