摘要目的 探讨降钙素原(PCT)对急性呼吸窘迫综合征(ARDS)患者早期病情评估和预后的判断价值.方法 采用前瞻性观察性研究方法,选择2012年10月至2016年4月江苏大学附属人民医院重症加强治疗病房(ICU)收治的113例需行机械通气的ARDS患者,按柏林标准根据氧合指数(PaO2/FiO2)分为轻、中、重度3组;选择同期25例健康体检者作为对照组.记录受试者一般情况、急性生理学与慢性健康状况评分系统Ⅱ(APACHEⅡ)评分和肺损伤评分(Murray评分).于确诊ARDS 24 h内,采用酶联荧光分析法检测血清PCT水平,采用散射免疫比浊法检测血清C-反应蛋白(CRP)水平.记录随访28 d后患者生存情况,比较存活组与死亡组的临床资料.各指标间相关性采用非参数Spearman等级相关分析;绘制受试者工作特征曲线(ROC),分析各指标对28 d预后的预测价值;采用Kaplan-Meier生存曲线分析比较不同PCT水平患者的28 d累积存活率.结果 排除和失访共24例,最终89例ARDS患者纳入分析,其中轻度27例,中度34例,重度28例.ARDS组与健康对照组年龄、性别差异无统计学意义;感染和创伤仍是并发ARDS的主要原因(分别占55.1%和34.8%).ARDS组血清CRP和PCT水平均较健康对照组显著升高〔CRP(mg/L):146.32(111.31,168.49)比6.08(4.47,7.89),PCT(μg/L):3.46(1.98,5.56)比0.02(0.01,0.04),均P<0.01〕,且随ARDS病程加重持续升高;重度组APACHEⅡ、Murray评分均明显高于轻度组.Spearman相关分析显示,ARDS患者血清PCT、CRP水平与APACHEⅡ评分均有较好的相关性(r值分别为0.669、0.601,均P<0.001);PCT与Murray评分存在弱相关(r=0.294,P=0.005),CRP与Murray评分则无相关性(r=0.203,P=0.052).死亡组(38例)ARDS患者APACHEⅡ评分和血清PCT水平均明显高于存活组(51例)患者〔APACHEⅡ评分(分):26.00(23.00,28.50)比21.00(17.00,25.00),PCT(μg/L):6.38(2.82,9.49)比3.09(1.08,3.57),均P<0.01〕;而两组Murray评分和CRP水平差异无统计学意义.ROC曲线分析显示,APACHEⅡ评分和PCT预测28 d预后的ROC曲线下面积(AUC)分别为0.781和0.793,均高于Murray评分和CRP的AUC(分别为0.606和0.561,均P<0.05);APACHEⅡ评分联合PCT的AUC显著高于单用PCT(0.859比0.793,P=0.048)或单用APACHEⅡ评分(0.859比0.781,P=0.038).PCT的临界值为4.35μg/L时,其预测28 d病死率的敏感度和特异度分别为92.2%和63.2%,阳性似然比和阴性似然比分别为2.50和0.12.Kaplan-Meier生存曲线分析显示,PCT>4.35μg/L时患者的28 d累积存活率较PCT≤4.35μg/L者显著降低(log-rank检验:χ2=5.013,P=0.025).结论 ARDS患者早期外周血PCT水平升高与肺损伤程度相关,对ARDS患者的病情及预后判断有指导意义.

abstractsObjective To investigate the value of procalcitonin (PCT) on predicting the severity and prognosis in patients with early acute respiratory distress syndrome (ARDS).Methods A prospective observation study was conducted. A total of 113 patients with ARDS undergoing mechanical ventilation admitted to intensive care unit (ICU) of Affiliated People's Hospital ofJiangsu University from October 2012 to April 2016 were enrolled. Based on oxygenation index (PaO2/FiO2), the patients were classified into mild, moderate, and severe groups according to Berlin Definition. Twenty-five healthy volunteers were served as controls. Demographics, acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score, and Murray lung injury score were recorded. Within 24 hours after diagnosis of ARDS, the serum levels of PCT and C-reactive protein (CRP) were determined by enzyme-linked fluorescence analysis (ELFA) and immune turbidimetric method, respectively. The patients were also divided into survival and non-survival groups according to clinical outcome within 28-day follow-up, and the clinical data were compared between the two groups. Spearman rank correlationwas applied to determine the correlation between variables. The predictive value of the parameters on 28-day mortality was evaluated with receiver operating characteristic curve (ROC). Kaplan-Meier survival curve analysis was used to compare different PCT levels of patients with 28-day cumulative survival rate. Results After excluding patients who did not meet the inclusion criteria and loss to follow-up, the final 89 patients were enrolled in the analysis. Among 89 ARDS patients analyzed, 27 of them were mild, 34 moderate, and 28 severe ARDS. No significant differences were found in age and gender between ARDS and healthy control groups. Infection and trauma were the most common etiology of ARDS (55.1% and 34.8%, respectively). Compared with healthy control group, both CRP and PCT in serum of ARDS group were higher [CRP (mg/L): 146.32 (111.31, 168.49) vs. 6.08 (4.47, 7.89), PCT (μg/L): 3.46 (1.98, 5.56) vs. 0.02 (0.01, 0.04), bothP < 0.01], and the two showed sustained upward trends with the ARDS course of disease. Compared with mild group, severe group had significantly higher APACHE Ⅱ and Murray scores. Spearman rank correlation analysis showed that both serum PCT and CRP in patients with ARDS was correlated well with APACHE Ⅱ score (r values were 0.669 and 0.601, respectively, bothP < 0.001), while PCT was weakly but positively correlated with Murray score (r = 0.294,P = 0.005), but not the case of CRP (r = 0.203,P = 0.052). APACHE Ⅱ score and serum PCT in non-survival group (n = 38) were significantly higher than those of the survival group [n = 51; APACHE Ⅱ score: 26.00 (23.00, 28.50) vs. 21.00 (17.00, 25.00), PCT (μg/L): 6.38 (2.82, 9.49) vs. 3.09 (1.08, 3.57), both P < 0.01], but Murray score and CRP level were similar between survivors and non-survivors. The areas under ROC curve (AUC) of APACHE Ⅱ score and PCT for predicting 28-day mortality were 0.781 and 0.793, respectively, which were better than those of AUC of Murray score and CRP (0.606 and 0.561, respectively, allP < 0.05). The AUC of APACHE Ⅱ score combined with PCT was significantly higher than that of PCT (0.859 vs. 0.793,P = 0.048) or APACHE Ⅱ score alone (0.859 vs. 0.781,P = 0.038). Using a PCT cut-off value of > 4.35μg/L for predicting 28-day mortality, the sensitivity and specificity was 92.2% and 63.2%, respectively, and the positive and negative likelihood ratios were 2.50 and 0.12 respectively. Kaplan-Meier survival curve analysis indicated that the patients whose PCT more than 4.35μg/L, had lower 28-day cummulative survival rate as compared with those with PCT ≤ 4.35μg/L (log-rank test: χ2 = 5.013,P = 0.025).Conclusion The elevated serum PCT level in patients with ARDS seems to be correlated well with the severity of lung injury, and appears to be a useful prognostic marker of outcome in the early phases of ARDS.