血管外肺水指数与肺血管通透性指数及胸腔内血容量指数对烧伤后肺水肿鉴别诊断的意义

Significance of extravascular lung water index, pulmonary vascular permeability index, and in- trathoracic blood volume index in the differential diagnosis of burn-induced pulmonary edema

目的评价血管外肺水指数（EVLWI）、肺血管通透性指数（PVPI）、胸腔内血容量指数（ITBVI）对严重烧伤后肺水肿类型鉴别诊断的意义。方法2011年12月-2014年9月，笔者单位烧伤科ICU收治38例接受机械通气及脉搏轮廓心排血量监测、伤后1周内并发肺水肿的严重烧伤患者，对其临床资料进行回顾性分析。将患者根据肺水肿类型分为肺损伤型组17例和静水压型组21例，比较2组患者EVLWI、PVPI、ITBVI、氧合指数、肺损伤评分，分析前4个指标之间的相关性，前3个指标与肺水肿类型的相关性。对数据行t检验、X2检验、Mann—WhitneyU检验、Pearson相关分析及准确性检验[受试者工作特征（ROC）曲线分析方法]。结果肺损伤型组患者EVLWI与静水压型组相近。分别为（12．9±3．1）、（12．1±32．1）mL／kg，U=159．5，P〉0．05。肺损伤型组患者PVPI为2．6±0．5、肺损伤评分为（2．1±0．6）分，明显高于静水压型组的1．4±0．3、（1．0±0．6）分，u值分别为4．5、36．5，P值均小于0．01。肺损伤型组患者ITBVI、氧合指数分别为（911±197）mL／m2、（136±69）mmHg（1mmHg=0．133kPa），低于静水压型组的（1305±168）mL／m2、（2124-60）mmHg，U值分别为21．5、70．5，P值均小于0．01。肺损伤型组患者EVLWI与PVPI、ITBVI均呈明显正相关（r值分别为0．553、0．807，P〈0．05或P〈0．01）；氧合指数与EVLWI、PVPI均呈明显负相关（r值分别为-0．674、-0．817，P值均小于0．01）。静水压型组患者EVLWI与ITBVI呈明显正相关（r=0．751，P〈0．01），与PVPI无明显相关性（r=-0．275，P〉0．05）；氧合指数与EVLWI、PVPI均无明显相关性（r值分别为0．197、0．062，P值均大于0．05）。PVPI值对烧伤后肺水肿类型鉴别诊断的ROC曲线下总面积为0．987（95％置信区间为0．962—1．013，P〈0．01），PVPI最佳阈值为1．9时，其敏感度为94．1％，特异度为95．2％。ITBVI值对烧伤后肺水肿类型鉴别诊断的ROC曲线下总面积为0．940（95％置信区间为0．860—1．020，P〈0．01），ITBVI最佳阈值为1077．5mL／m2时，其敏感度为95．2％。特异度为88．2％。结论EVLWI、ITBVI、PVPI对肺水肿类型的鉴别有重要意义，有利于烧伤后肺水肿的早期诊断和准确治疗。

Objective To appraise the significance of extravascular lung water index （ EVLWI ） , pulmonary vascular permeability index （PVPI） , and intrathoraeic blood volume index （ITBVI） in the differ- ential diagnosis of the type of burn-induced pulmonary edema. Methods The clinical data of 38 patients, with severe burn hospitalized in our burn ICU from December 2011 to September 2014 suffering from the complication of pulmonary edema within one week post burn and treated with mechanical ventilation accom-panied by pulse contour cardiac output monitoring, were retrospectively analyzed. The patients were divided into lung injury group （L, n = 17） and hydrostatic group （H, n = 21 ） according to the diagnosis of pulmo- nary edema. EVLWI, PVPI, ITBVI, oxygenation index, and lung injury score （L/S） were compared be- tween two groups, and the correlations among the former four indexes and the correlations between each of the former three indexes and types of pulmonary edema were analyzed. Data were processed with t test, chi- square test, Mann-Whitney U test, Pearson correlation test, and accuracy test [ receiver operating character- istic （ROC） curve ]. Results There was no statistically significant difference in EVLWI between group L and group H, respectively （12.9 ±3.1） and （12.1 ±2.1） mL/kg, U =159.5, P 〉0.05. The PVPI and LIS of patients in group L were respectively 2.6 ± 0.5 and （2.1 ± 0.6） points, and they were significantly higher than those in group H [ 1.4 ± 0.3 and （ 1.0 ± 0.6） points, with U values respectively 4.5 and 36.5, P values below 0.01 ]. The ITBVI and oxygenation index of patients in group L were respectively （911 ± 197） mL/m2 and （136 ± 69） mmHg （1 mmHg = 0. 133 kPa） , which were significantly lower than those in group H [ （ 1 305 ± 168） mL/m2 and （212 ± 60） mmHg, with U values respectively 21.5 and 70.5, P values below 0.01 ]. In group L, there was obviously positive correlation between EVLWI and PVPI, or EVLWI and ITBVI （ with r values respectively 0. 553 and 0. 807, P 〈 0.05 or P 〈 0.01 ） , and there was obviously negative correlation between oxygenation index and EVLWI, or oxygenation index and PVPI （with r values respectively - 0. 674 and - 0. 817, P values below 0.01 ）. In group H, there was obviously positive correla- tion between EVLWI and ITBVI （ r = 0. 751, P 〈 0. 01 ） but no obvious correlation between EVLWI and PVPI, oxygenation index and EVLWI, or oxygenation index and PVPI （with r values respectively - 0. 275, 0. 197, and 0. 062, P values above 0.05）. The total area under ROC curve of PVPI value for differentiating the type of pulmonary edema was 0. 987 [ with 95% confidence interval （CI） 0. 962 - 1. 013, P 〈 0.01 ] , and 1.9 was the cutoff value with sensitivity of 94.1% and specificity of 95.2%. The total area under ROC curve of ITBVI value for differentiating the type of pulmonary edema was 0. 940 （with 95% CI 0. 860 - 1. 020, P 〈0.01 ）, and 1 077.5 mL/m2 was the cutoff value with sensitivity of 95.2% and specificity of 88.2%. Conclusions EVLWI, PVPI, and ITBVI have an important significance in the differential diag- nosis of the type of burn-induced pulmonary edema, and they may be helpful in the early diagnosis and man- agement of burn-induced pulmonary edema.