Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
Department of Boistatistics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
Thorax. 2018 Sep;73(9):840-846. doi: 10.1136/thoraxjnl-2017-211280. Epub 2018 Jun 14.
There is no accurate, non-invasive measurement to estimate the degree of pulmonary oedema in acute respiratory distress syndrome (ARDS). We developed the Radiographic Assessment of Lung Oedema (RALE) score to evaluate the extent and density of alveolar opacities on chest radiographs. After first comparing the RALE score to gravimetric assessment of pulmonary oedema in organ donors, we then evaluated the RALE score in patients with ARDS for its relationship to oxygenation and clinical outcomes.
We compared radiographs with excised lung weights from 72 organ donors (derivation cohort) and radiographs with clinical data from 174 patients with ARDS in the ARDSNet Fluid and Catheter Treatment Trial (validation cohort). To calculate RALE, each radiographic quadrant was scored for extent of consolidation (0-4) and density of opacification (1-3). The product of the consolidation and density scores for each of the four quadrants was summed (maximum score=48).
Agreement between two independent reviewers for RALE score was excellent (intraclass correlation coefficient=0.93, 95% CI 0.91 to 0.95). In donors, pre-procurement RALE score correlated with height-adjusted total lung weight (ρ=0.59, p<0.001). In patients with ARDS, higher RALE scores were independently associated with lower PaO/fractional inspired oxygen and worse survival. Conservative fluid management significantly decreased RALE score over 3 days compared with liberal fluid management.
The RALE score can be used to assess both the extent of pulmonary oedema and the severity of ARDS, by utilising information that is already obtained routinely, safely and inexpensively in every patient with ARDS. This novel non-invasive measure should be useful for assessing ARDS severity and monitoring response to therapy.
目前尚无准确、无创的方法来评估急性呼吸窘迫综合征（ARDS）患者的肺水肿程度。我们开发了放射学肺水肿评估（RALE）评分，用于评估胸部 X 线片上肺泡混浊的程度和密度。首先，我们将 RALE 评分与器官捐献者肺湿重的称重评估进行比较，然后在 ARDS 患者中评估 RALE 评分与氧合和临床结局的关系。
我们比较了 72 名器官捐献者的 X 线片和切除肺重量（推导队列），以及 ARDSNet 液体和导管治疗试验（验证队列）中 174 名 ARDS 患者的 X 线片和临床数据。为了计算 RALE，对每个放射象限的实变程度（0-4 分）和混浊密度（1-3 分）进行评分。四个象限的实变和密度评分的乘积相加（最大得分为 48 分）。
两名独立评审员对 RALE 评分的一致性非常好（组内相关系数=0.93，95%CI 0.91 至 0.95）。在供者中，术前 RALE 评分与身高校正的总肺重量相关（ρ=0.59，p<0.001）。在 ARDS 患者中，较高的 RALE 评分与较低的 PaO/吸入氧分数和较差的生存率独立相关。与自由液体管理相比，保守液体管理在 3 天内显著降低了 RALE 评分。
RALE 评分可用于评估肺水肿的程度和 ARDS 的严重程度，方法是利用每个 ARDS 患者常规、安全且经济地获得的信息。这种新的非侵入性测量方法应该有助于评估 ARDS 的严重程度和监测治疗反应。
