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. 2023 Jun 23;160(12):531-539.
doi: 10.1016/j.medcli.2023.01.024. Epub 2023 Mar 10.

Lung ultrasound score severity cut-off points in COVID-19 pneumonia. A systematic review and validating cohort

[Article in English, Spanish]
Jaime Gil-Rodríguez  1 , Michel Martos-Ruiz  1 , Alberto Benavente-Fernández  1 , Pablo Aranda-Laserna  1 , Miguel Ángel Montero-Alonso  2 , José-Antonio Peregrina-Rivas  3 , Daniel Fernández-Reyes  1 , Javier Martínez de Victoria-Carazo  1 , Emilio Guirao-Arrabal  4 , José Hernández-Quero  3
Affiliations

Lung ultrasound score severity cut-off points in COVID-19 pneumonia. A systematic review and validating cohort

[Article in English, Spanish]
Jaime Gil-Rodríguez et al. Med Clin (Barc). .

Abstract
in English, Spanish

Objectives: Our purpose was to establish different cut-off points based on the lung ultrasound score (LUS) to classify COVID-19 pneumonia severity.

Methods: Initially, we conducted a systematic review among previously proposed LUS cut-off points. Then, these results were validated by a single-centre prospective cohort study of adult patients with confirmed SARS-CoV-2 infection. Studied variables were poor outcome (ventilation support, intensive care unit admission or 28-days mortality) and 28-days mortality.

Results: From 510 articles, 11 articles were included. Among the cut-off points proposed in the articles included, only the LUS>15 cut-off point could be validated for its original endpoint, demonstrating also the strongest relation with poor outcome (odds ratio [OR]=3.636, confidence interval [CI] 1.411-9.374). Regarding our cohort, 127 patients were admitted. In these patients, LUS was statistically associated with poor outcome (OR=1.303, CI 1.137-1.493), and with 28-days mortality (OR=1.024, CI 1.006-1.042). LUS>15 showed the best diagnostic performance when choosing a single cut-off point in our cohort (area under the curve 0.650). LUS≤7 showed high sensitivity to rule out poor outcome (0.89, CI 0.695-0.955), while LUS>20 revealed high specificity to predict poor outcome (0.86, CI 0.776-0.917).

Conclusions: LUS is a good predictor of poor outcome and 28-days mortality in COVID-19. LUS≤7 cut-off point is associated with mild pneumonia, LUS 8-20 with moderate pneumonia and ≥20 with severe pneumonia. If a single cut-off point were used, LUS>15 would be the point which better discriminates mild from severe disease.

Objetivos: Establecer diferentes puntos de corte basados en el Lung Ultrasound Score (LUS) para clasificar la gravedad de la neumonía COVID-19.

Métodos: Inicialmente, realizamos una revisión sistemática entre los puntos de corte LUS propuestos previamente. Estos resultados fueron validados por una cohorte prospectiva unicéntrica de pacientes adultos con infección confirmada por SARS-CoV-2. Las variables analizadas fueron la mala evolución y la mortalidad a los 28 días.

Resultados: De 510 artículos, se incluyeron 11. Entre los puntos de corte propuestos en los artículos incluidos, solo LUS > 15 pudo ser validado para su objetivo original, demostrando también la relación más fuerte con mala evolución (odds ratio [OR] = 3,636, intervalo de confianza [IC] 1,411-9,374). Respecto a nuestra cohorte, se incluyeron 127 pacientes. En estos pacientes, el LUS se asoció estadísticamente con mala evolución (OR = 1,303, IC 1,137-1,493) y con mortalidad a los 28 días (OR = 1,024, IC 1,006-1,042). LUS > 15 mostró el mejor rendimiento diagnóstico al elegir un único punto de corte en nuestra cohorte (área bajo la curva 0,650). LUS ≤ 7 mostró una alta sensibilidad para descartar mal resultado (0,89, IC 0,695-0,955), mientras que LUS > 20 reveló gran especificidad para predecir mala evolución (0,86, IC 0,776-0,917).

Conclusiones: LUS es un buen predictor de mala evolución y mortalidad a 28 días en COVID-19. LUS ≤ 7 se asocia con neumonía leve, LUS 8-20 con neumonía moderada y ≥ 20 con neumonía grave. Si se utilizara un único punto de corte, LUS > 15 sería el que mejor discriminaría la enfermedad leve de la grave.

Keywords: COVID-19; Disease severity; Ecografía; Gravedad de la enfermedad; Lung; Mortalidad; Mortality; Pulmonar; SARS-CoV-2; Ultrasound.

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Figures

Fig. 1
Fig. 1
Lung areas distribution and LUS (a) 0 points [normal A-lines pattern]; (b) 1 point [> 3 B-lines]; (c) 2 points [coalescing B-lines and/or subpleural consolidation]; (d) 3 points [pulmonary consolidation or “with lung”].
Fig. 2
Fig. 2
Flow diagram for article selection according to PRISMA 2020 guidelines.
Fig. 3
Fig. 3
Participant flow diagram according to TRIPOD 2015 guidelines.
Fig. 4
Fig. 4
Cox regression between (a) LUS and poor outcome, and (b) LUS and 28-days mortality.
See this image and copyright information in PMC

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