血液学相关指标在ICU肿瘤患者细菌感染早期诊断中的应用

目的：测定重症加强护理病房（ICU）肿瘤患者血液学相关指标水平，探讨其在诊断ICU肿瘤患者早期细菌感染中的临床应用。方法：回顾性分析ICU中256例肿瘤患者完整临术资料，根据临床细菌感染标准分为感染组（67例）和非感染组（189例），根据死亡情况分为存活组（193例）和死亡组（63例），测定感染组和非感染组ICU肿瘤患者凝血酶原时间（PT）、活化部分凝血酶原时间（APTT）和D-二聚体（DD）、降钙素原（PCT）水平及白细胞（WBC）、中性粒细胞（NEU）、淋巴细胞（LYM）计数，并计算中性粒细胞/淋巴细胞比值（NLR）。通过受试者工作特征曲线（ROC）和ROC曲线下面积（AUC）评价上述指标诊断ICU肿瘤患者早期细菌感染以及PCT预测ICU早期细菌感染肿瘤患者死亡风险的灵敏度和特异度。结果：与非感染组比较，感染组ICU肿瘤患者PT、APTT、DD、PCT和NLR均明显升高（P<0.05或P<0.01）。与PCT<0.25 μg·L^-1组比较，0.25 μg·L^-1≤PCT<2.00 μg·L^-1、2.00 μg·L^-1≤PCT<10.00 μg·L^-1和PCT≥10.00 μg·L^-1组ICU早期细菌感染肿瘤患者DD和NLR水平均明显升高（P<0.05或P<0.01），2.00 μg·L^-1≤PCT<10.00 μg·L^-1和PCT≥10.00 μg·L^-1组ICU早期细菌感染肿瘤患者PT和APTT均明显升高（P<0.05）。PT、APTT、DD、NLR和PCT诊断ICU肿瘤患者早期细菌感染的AUC、灵敏度和特异度分别为0.636、60.8%和59.1%，0.622、64.6%和58.1%，0.672、69.6%和58.1%，0.752、74.7%和65.6%以及0.855、70.9%和83.9%，差异均有统计学意义（P<0.01）；死亡组ICU早期细菌感染肿瘤患者PCT水平明显高于生存组（P<0.05），PCT预测ICU早期细菌感染肿瘤患者死亡风险的AUC为0.803（95% CI：0.749~0.857），临界（Cut-off）值为6.72 μg·L^-1，灵敏度和特异度分别为63.2%和79.1%，差异有统计学意义（P<0.01）。结论：PT、APTT、DD、PCT和NLR可作为ICU肿瘤患者早期细菌感染的诊断指标，NLR灵敏度最高，PCT特异度最高，PCT可作为ICU早期细菌感染肿瘤患者死亡风险的预测指标。

Application of hematology-related indexes in early diagnosis of bacterial infectionof tumor patients in ICU

Objective: To detect the levels of the hematology-related indexes in the tumor patients in intensive care unit(ICU), and to investgate their clinical application in the early diagnosis of bacterial infection in the tumor patients in ICU. Methods: The complete clinical materials of 256 tumor patients in ICU were analyzed retrospectively. According to the clinical bacterial infection standard, they were divided into infection group(67 cases) and non-infection group(189 cases), and according to the situation of death of patients, they were divided into survival group(193 cases) and death group(63 cases). The prothrombin time (PT), active part thrombin time (APTT) and D-Dimer(DD),the levels of procalcitonin (PCT) and the counts of white blood cell(WBC), neutrophile(NEU), lymphocyte(LYM) of the tumor patients in ICU in infection group and non-infection group were measured, and the neutrophile-to-lymphocyte ratio(NLR) was calculated. The sensitivities and specificities of each index in the early diagnosis of bacterial infection in the ICU tumor patients and PCT for predicting the mortality risk in the ICU tumor patients with early bacterial infection were assessed by receiver operating characteristic curve(ROC) and the area under the curve(AUC), and the their clinical values were explored. Results: Compared with non-infection group, the PT, APTT, DD, PCT level and NRL of the ICU tumor patients in infection group were significantly increased(P<0.05 or P<0.01).Compared with PCT<0.25 μg·L^-1 group, the DD and NRL levels of the ICU tumor patients with early bacterial infection in 0.25 μg·L^-1 ≤ PCT<2.00 μg·L^-1 group,2.00 μg·L^-1 ≤ PCT<10.00 μg·L^-1 group and PCT ≥ 10.00 μg·L^-1 group were significantly increased(P<0.05 or P<0.01); the PT and APTT levels of the ICU tumor patients with early bacterial infection in 2.00 μg·L^-1 ≤ PCT<10.00 μg·L^-1 group and PCT ≥ 10.00 μg·L^-1 group were significantly increased(P<0.05).The AUC, sensitivities and specificities of PT, APTT, DD, NLR and PCT in the diagnosis of early bacterial infection in the ICU tumor patients were 0.636, 60.8%, 59.1%; 0.622, 64.6%, 58.1%;0.672, 69.6%, 58.1%;0.752, 74.7%, 65.6%; 0.855, 70.9%, 83.9%; the differences were statistically significant (P<0.01).The PCT level of ICU tumor patients with early bacterial infection in death group was significantly higher than that in survival group (P<0.05).The AUC of PCT for predicting the mortality risk of ICU tumor patients with early bacterial infection was 0.803(95%CI:0.749-0.857), the cut-off value was 6.72 μg·L^-1, the sensitivity and specificity were 63.2% and 79.1%, respectively, and the differences were statistically significant (P<0.01). Conclusion: PT, APTT, DD, PCT and NLR can be used as the early diagnostic indicators of bacterial infection in the ICU tumor patients. The sensitivity of NLR and the specificity of PCT were the highest. PCT can be used as a predictor of the mortality risk in the ICU tumor patients with early bacterial infection.