探讨血管外肺水指数(EVLWI)、降钙素原(PCT)对革兰氏阴性杆菌烧伤脓毒症病情严重程度的评估作用。

选择2015年3月至2019年3月武汉大学同仁医院暨武汉市第三医院烧伤科收治的20例血培养为革兰氏阴性杆菌烧伤脓毒症患者(革兰氏阴性杆菌烧伤脓毒症组)及18例血培养为非革兰氏阴性杆菌烧伤脓毒症患者(非革兰氏阴性杆菌烧伤脓毒症组)。2组患者均行脉搏指示连续心输出量(PiCCO)监测，并分别在诊断为脓毒症与脓毒症休克时记录EVLWI的数值变化，连续测量3次，取其平均值；同时在确诊脓毒症与脓毒症休克时立即行静脉血的采集，采集非抗凝血3 mL，离心后留取血清并行PCT的检测，记录2组PCT值。比较2组确诊脓毒症与脓毒症休克时EVLWI及PCT，对数据行t检验并行Bonferroni校正。绘制EVLWI及血清PCT预测革兰氏阴性杆菌烧伤脓毒症与脓毒症休克患者的受试者工作特征(ROC)曲线，计算诊断革兰氏阴性杆菌烧伤脓毒症或脓毒症休克的95%的置信区间、约登指数、最佳临界值、灵敏度和特异度。

诊断为脓毒症时，革兰氏阴性杆菌烧伤脓毒症组患者的EVLWI、PCT水平分别为(10.6±1.6) mL/kg、(6.64±1.63) ng/mL，均高于非革兰氏阴性杆菌烧伤脓毒症组[(7.9±1.7) mL/kg、(4.60±1.31) ng/mL]，差异均有统计学意义(t＝5.043、4.206，P值均小于0.05)。诊断为脓毒症休克时，革兰氏阴性杆菌烧伤脓毒症组患者的EVLWI、PCT水平分别为(15.0±1.3) mL/kg、(12.87±2.65) ng/mL，均高于非革兰氏阴性杆菌烧伤脓毒症组[(10.7±1.5) mL/kg、(6.29±1.79) ng/mL]，差异均有统计学意义(t＝9.608、8.867，P值均小于0.05)。通过绘制ROC曲线可以得知，应用EVLWI及PCT判断革兰氏阴性杆菌烧伤脓毒症及非革兰氏阴性杆菌烧伤脓毒症的最佳临界值分别为10.5 mL/kg、5.9 ng/mL；约登指数分别为50%、59%，灵敏度分别为50%、70%，特异度分别为100%、89%。EVLWI及PCT判断革兰氏阴性杆菌烧伤脓毒症休克及非革兰氏阴性杆菌烧伤脓毒症休克的最佳临界值分别为13.5 mL/kg、9.2 ng/mL；约登指数分别为90%、95%，灵敏度分别为90%、95%，特异度均为100%。

EVLWI及PCT可作为革兰氏阴性杆菌烧伤脓毒症病情严重程度的有效评估指标，可进一步提高革兰氏阴性杆菌烧伤脓毒症危险预测性的准确度。

To evaluate the effect of extravascular lung water index (EVLWI) and procalcitonin (PCT) on the severity of burn sepsis caused by Gram-negative bacilli.

From March 2015 to March 2019, 20 patients with burn sepsis of Gram-negative bacilli (Gram-negative bacilli burn sepsis group) and 18 patients with burn sepsis of non Gram-negative bacilli (non Gram-negative bacilli burn sepsis group) who were hospitalized in the Department of Burns, Tongren Hospital of Wuhan University & Wuhan Third Hospital were selected in this study. The patients in both groups were monitored with pulse indicating continuous cardiac output (PiCCO), and the changes of values of EVLWI when diagnosed sepsis and septic shock were recorded. The values were averaged for 3 times, and the mean values were taken. When the patients were diagnosed with sepsis or septic shock, venous bloods of patients were collected immediately, 3 mL of non-anticoagulant blood was collected, and serum was retained after centrifugation and detected for PCT, and the PCT values of patients were recorded in both groups. The differences of EVLWI and PCT between the two groups were compared, and data were processed with t test, Bonferroni correction. The receiver operating characteristic (ROC) curves of EVLWI and serum PCT in predicting burn sepsis and septic shock patients with Gram-negative bacilli were drawn, and 95% confidence interval, Youden index, best critical value, sensitivity and specificity for the diagnosis of burn sepsis or septic shock patients caused by Gram-negative bacilli were calculated.

When the patients were diagnosed for sepsis, the values of EVLWI and PCT of patients in Gram-negative bacilli burn sepsis group were (10.6 ± 1.6) mL/kg and (6.64 ± 1.63) ng/mL respectively, which were higher than those in non Gram-negative bacilli burn sepsis group [(7.9±1.7) mL/kg and (4.60±1.31) ng/mL respectively], and the differences between the two groups were statistically significant (t=5.043, 4.206; with P values below 0.05). When the patients were diagnosed for sepsis shock, the values of EVLWI and PCT of patients in Gram-negative bacilli burn sepsis group were (15.0±1.3) mL/kg and (12.87±2.65) ng/mL respectively, which were higher than those in non Gram-negative bacilli burn sepsis group [(10.7±1.5) mL/kg and (6.29±1.79) ng/mL], and the differences between the two groups were statistically significant (t=9.608, 8.867; with P values below 0.05). By drawing ROC curve, the values of EVLWI and PCT which were used to determine the best critical values of burn sepsis patients caused by Gram-negative bacilli and burn sepsis patients caused by non Gram-negative bacilli were 10.5 mL/kg and 5.9 ng/mL respectively, with Youden index of 50% and 59%, sensitivity of 50% and 70%, and specificity of 100% and 89% respectively. The best critical values of EVLWI and PCT in the diagnosis of burn septic shock of gram negative bacilli and burn septic shock of non gram negative bacilli were 13.5 mL/kg and 9.2 ng/mL respectively, with Youden index of 90% and 95%, sensitivity of 90% and 95%, and specificity of 100% and 100% respectively.

EVLWI and PCT can be used as effective indexes to evaluate the severity of burn sepsis caused by Gram-negative bacilli, and can further improve the accuracy of risk prediction of burn sepsis caused by Gram-negative bacilli.