ALI／ARDS患者呼出气冷凝液中H2O2检测的临床意义

Detection in exhaled breath condensate of patients with acute lung injury/acute respiratory distress syndrome

目的研究急性肺损伤／急性呼吸窘迫综合征（ALL／ARDs）患者呼出气冷凝液（EBC）中过氧化氢（H2O2）浓度的临床意义。方法32例ICU中行机械通气的ALI／ARDS患者为研究组，采用改进的EcoScreen呼出气冷凝液收集器收集患者第1天和第5天的EBC标本。24例健康体检者为对照组，自主呼吸收集EBC。全部对象同步抽取静脉血离心留取血清。用ELISA法测定EBC和血清中的H2O2浓度。动态观察不同分组对象EBC和血清中H2O2的差异，并进行临床指标的相关性分析。结果①ALI／ARDS患者EBC～H2O2水平（187．19±25．94）nmol／mL高于健康对照组（95．25士21．15）nmol／mL（P〈0．01）；②24h内EBC—H2O2水平ARDS组（198．79±27．87）nmol／mL高于ALl组（166．42±36．19）nmol／mL（P〈0．05），第5天EBC—H2O2水平ARDS组（169．12±33．50）nmol／mL高于ALl组（124．81±29．16）nmol／mL（P〈0．01）；③24h内EBC—H2O2水平LIS〉2．5组（201．08±22．50）nmol／mL高于LIS≤2．5组（180．88±25．35）nmol／mL（P〈0．05），第5天EBC—H202水平LIS〉2．5组（158．41±29．45）nmol／mL高于LIS≤2．5组（123．40±26．15）nmol／mL（P〈0．01）；④第5天EBC—H2O2水平病死组（150．97±32．33）nmol／mL高于存活组（125．63±27．85）nmol／mL（P〈0．05）；⑤EBC和血清中H2O2均与A—aDO2、LIS值、X片、PEEP、MEWS评分呈正相关，与PaO2、PaO2／FiO2、PaO2／PAO2呈负相关，EBC—H2O2与肺顺应性呈负相关。结论检测EBC中H2O2水平的变化可反映ALI／ARDS患者肺部存在氧化应激、炎症反应，可作为Au诊断的辅助指标之一，且在评估肺损伤的严重程度、评价治疗效果和估计预后方面优于血清H2O2检测。

Objective To measure the H2O2 of the exhaled breath condensate （EBC）in the patients with acute lung injury/acute respiratory distress syndrome （ ALL/ARDS ） in order to study the relationships with the severity of the lung injury. Methods The study group included 32 ALI/ARDS patients with mechanical ventilation in ICU. EBC samples of the study group were collected on the 1 st day and the 5th day by modified EcoScreen condenser with the synchronous collection of the venous blood. EBC samples of 24 healthy volunteers in control group were collected by the conventional method of spontaneous breathing. The concentrations of H2O2 in the EBC and serum were measured by ELISA. The levels of H2O2 of patients with different grades of lung injuries were observed, and correlation were analyzed between the levels of H2O2 and clinical indicators. Results （1）The level of EBC -H2O2 was significantly higher in patients with ALI/ARDS group [ （187.19± 25.94 ） nmol/mL] than in the control group[ （95.25 ±21.15） nmol/mL] （P 〈0.01 ） ; （2）There was significantly higher EBC -H2O2 level in ARDS group on the 1st day [ （ 198.79 ± 27.87） nmol/mL], the 5th day [ （ 169.12± 33.50） nmol/ mL] compared with that of ALI group on the 1st day [ （166.42 ± 36. 19） nmol/mLJ, the 5th day [ （ 124.81± 29.16） nmol/mL ] （P 〈 0. 05, P 〈 0. 01, respectively） ; （3）There was significantly higher EBC- H202 level in LIS 〉 2.5 group on the 1st day [ （201.08 ± 22.50） nmol/mL], the 5th day [ （ 158.41 ±29.45 ） nmol/mL ] compared with that of LIS ≤ 2.5 group on the 1 st day [ （ 180.88± 25.35） nmol/mL], the 5th day [ （ 123.40 ±26.15） nmol/mL] （P 〈0.05, P 〈0.01, respectively） ; （4）EBC - H202 level was higher in death group on the 5th day [ （ 150.97 ± 32, 33 ） nmol/mL] than in survival group [ （ 125.63± 27.85 ） nmol/mL ] （ P 〈 0.05 ） ; （5）The levels of EBC - H2O2 and venous blood H2 05 were positively correlated with A - a DO2, lung injury score, X - ray score, PEEP, MEWS score. They were negatively correlated with PaO2, PaO2/FiO2 ,PaO2/PAO2. The levels of EBC -H2O2were negatively correlated with lung compliance. Conclusion The levels of H2O2 in EBC of patients with ALI/ARDS could reflect the degree of oxidative stress and inflammatory response and be used as auxiliary diagnostic indicator of acute lung injury. EBC - H2O2 could be superior to venous blood H2O2 in assessing the degree of lung injury, curative effect and prognosis of ALI/ARDS.