Background 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.
Methods 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).
Results 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 PaO2/fractional inspired oxygen and worse survival. Conservative fluid management significantly decreased RALE score over 3 days compared with liberal fluid management.
Conclusions 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.
- imaging/CT MRI etc
- pulmonary oedema
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Contributors MAW and LBW contributed to data collection. MAW, ZZ, TK and LBW contributed to figures. MAW, JAB, CMS, MWS, TWR, MAM, CSC and LBW contributed to the study design. All authors contributed to data analysis, data interpretation and writing of the manuscript.
Funding Funding for this study was provided by NIH HL103836, R37 HL51856, HL131621, HL126671, Courtney’s Race for the ARDS Cure and the Courtney Charneco Family.
Competing interests JAB has received research funding from the National Institutes of Health and Global Blood Therapeutics. TWR has received consulting fees from Avisa Pharma and Cumberland Pharmaceuticals. CSC has received research funding from the National Institutes of Health, the Food and Drug Administration (FDA), the Department of Defense, Bayer and GlaxoSmithKline. She has received consulting fees from GlaxoSmithKline, Boehringer Ingelheim, Bayer, Prometic, CSL Behring and Roche/Genentech. MAM has received research grants from Amgen and GlaxoSmithKline and has a current research grant from Bayer Pharmaceuticals for ARDS studies. He has received consultation fees from CSL Behring, Boehinger Ingelheim, Cerus Therapeutics, Quark Pharmaceuticals, Thesan Pharmaceuticals and Bayer Pharmaceuticals. He was Chair of a DSMB for Asthma trials for Roche-Genentech (2013-2017). He also receives grant support for research and clinical trials from the NHLBI, FDA and the Department of Defense. LBW has received research funding from the National Institutes of Health, Boehringer Ingelheim and Global Blood Therapeutics and consultant fees from CSL Behring.
Patient consent Not required.
Ethics approval Institutional IRBs at all FACTT study sites.
Provenance and peer review Not commissioned; externally peer reviewed.
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