摘要目的:探讨生长分化因子- 15（GDF-15）和血管外肺水指数（EVLWI）在急性呼吸窘迫综合征（ARDS）患者严重程度分级及预后预测中的应用价值。方法:选择2019年1月至2020年2月郑州大学附属郑州中心医院呼吸重症监护病房（RICU）收治的18～75岁ARDS患者为研究对象。所有患者均根据病情进行机械通气、抗感染、维持水和电解质及酸碱内环境稳定、血液净化及营养支持等常规治疗，并于入科后行脉搏指示连续心排血量监测（PiCCO），记录治疗前及治疗24、48、72 h的EVLWI；同期采用酶联免疫吸附试验（ELISA）检测血清GDF-15水平。根据ARDS 2012柏林标准将患者分为轻、中、重度，比较不同病情程度患者治疗前后EVLWI、GDF-15水平。此外，GDF-15以3 458 ng/L、EVLWI以15 mL/kg为界限，比较分析不同GDF-15或EVLWI水平患者重症监护病房（ICU）住院时间、ICU病死率和28 d病死率。结果:共入选82例ARDS患者，轻度22例，中度28例，重度32例。中、重度组ARDS患者治疗前后各时间点GDF-15、EVLWI水平均高于轻度ARDS者。重度ARDS患者GDF-15和EVLWI水平均高于中度组，除治疗24 h GDF-15水平差异无统计学意义外（ng/L：3 900.41±546.43比3 695.66±604.73， P>0.05），其他各时间点差异均有统计学意义〔GDF-15（ng/L）：治疗前为3 786.11±441.45比3 106.83±605.09，48 h为3 895.48±558.96比3 333.29±559.66，72 h为3 397.33±539.56比3 047.53±499.57；EVLWI（mL/kg）：治疗前为19.06±1.91比14.31±1.50，24 h为18.56±2.23比13.26±1.69，48 h为17.23±1.76比12.45±1.36，72 h为15.47±1.81比11.13±2.19，均 P<0.05〕。根据截断值处理，GDF-15≥3 458 ng/L和GDF-15<3 458 ng/L者各23例，EVLWI≥15 mL/kg、EVLWI<15 mL/kg者各23例；高GDF-15者ICU住院时间和28 d病死率显著高于低GDF-15者〔ICU住院时间（d）：21.22±2.69比15.37±3.14，28 d病死率：56.5%比21.7%，均 P<0.05〕；高EVLWI患者ICU住院时间和28 d病死率也显著高于低EVLWI患者〔ICU住院时间（d）：18.45±2.61比14.98±2.75，28 d病死率：47.8%比17.4%，均 P<0.05〕。 结论:GDF-15和EVLWI水平一定程度上能够反映ARDS患者病情严重程度，且高GDF-15和EVLWI水平与ARDS患者不良预后显著相关。

abstractsObjective:To investigate the value of growth differentiation factor-15 (GDF-15) and extravascular lung water index (EVLWI) in severity grading and prognosis prediction of patients with acute respiratory distress syndrome (ARDS).Methods:Patients with ARDS aged 18-75 years admitted to the department of respiratory intensive care unit (RICU) of Zhengzhou Central Hospital Affiliated to Zhengzhou University from January 2019 to February 2020 were enrolled. All patients were treated with conventional therapies such as mechanical ventilation, anti-infection, stabilization of water, electrolytes and acid-base environment, blood purification and nutritional support according to their conditions. Besides, the pulse-indicated continuous cardiac output (PiCCO) was performed after admission to the department, and EVLWI before treatment and at 24, 48 and 72 hours of treatment were recorded. Serum GDF-15 level was measured by enzyme linked immunosorbent assay (ELISA) during the same period. Patients were classified as mild, moderate, and severe degree according to the 2012 Berlin Definition of ARDS, and EVLWI and GDF-15 levels in patients with different disease levels before and after treatment were compared. In addition, the length of intensive care unit (ICU) stay, ICU mortality, and 28-day mortality of patients with different GDF-15 or EVLWI levels were analyzed comparatively, with the GDF-15 3 458 ng/L and EVLWI 15 mL/kg as the cut point.Results:A total of 82 patients with ARDS were enrolled, including 22 patients with mild ARDS, 28 patients with moderate ARDS, and 32 patients with severe ARDS. The GDF-15 and EVLWI levels in patients with moderate and severe ARDS at each time point before and after treatment were higher than those in patients with mild ARDS. Both GDF-15 and EVLWI levels in patients with severe ARDS were higher than those in the patients with moderate ARDS. The differences were statistically significant at all the time points except for the difference of GDF-15 levels at 24 hours after treatment (ng/L: 3 900.41±546.43 vs. 3 695.66±604.73, P > 0.05). [GDF-15 (ng/L): 3 786.11±441.45 vs. 3 106.83±605.09 before treatment, 3 895.48±558.96 vs. 3 333.29±559.66 at 48 hours, 3 397.33±539.56 vs. 3 047.53±499.57 at 72 hours; EVLWI (mL/kg): 19.06±1.91 vs. 14.31±1.50 before treatment, 18.56±2.23 vs. 13.26±1.69 at 24 hours, 17.23±1.76 vs. 12.45±1.36 at 48 hours, 15.47±1.81 vs. 11.13±2.19 at 72 hours, all P < 0.05]. According to the cut-off value, there were 23 patients with GDF-15 ≥ 3 458 ng/L and GDF-15 < 3 458 ng/L respectively and there were 23 patients with EVLWI ≥ 15 mL/kg and EVLWI < 15 mL/kg respectively. The length of ICU stay and 28-day mortality in patients with high GDF-15 were significantly higher than those in patients with low GDF-15 [length of ICU stay (days): 21.22±2.69 vs. 15.37±3.14, 28-day mortality: 56.5% vs. 21.7%, both P < 0.05]. The length of ICU stay and 28-day mortality in patients with high EVLWI were also significantly higher than those in patients with low EVLWI [length of ICU stay (days): 18.45±2.61 vs. 14.98±2.75, 28-day mortality: 47.8% vs. 17.4%, both P < 0.05]. Conclusion:To some extent, GDF-15 and EVLWI levels reflect the severity of patients with ARDS, and high GDF-15 and EVLWI levels are significantly associated with poor prognosis in patients with ARDS.