Pleural lung sliding quantification using a speckle tracking technology: A feasibility study on 30 healthy volunteers.

INTRODUCTION: Speckle tracking technology quantifies lung sliding and detects lung sliding abolition in case of pneumothorax on selected ultrasound loops through the analysis of acoustic markers. OBJECTIVES: We aimed to test the ability of speckle tracking technology to quantify lung sliding using a pleural strain value (PS). METHODS: We performed a prospective study in 30 healthy volunteers in whom we assessed the pleural speckle tracking using ultrasound loops. Seven breathing conditions with and without non-invasive ventilation were tested. Two observers analyzed the ultrasound loops in four lung areas (anterior and posterior, left and right) and compared the obtained PS values. The first endpoint was to determine the feasibility of the PS measurement in different breathing conditions. The secondary endpoints were to assess the intra- and inter-observer's reliability of the measurement to compare PS values between anterior and posterior lung areas and to explore their correlations with the measured tidal volume. RESULTS: We analyzed 1624 ultrasound loops from 29 patients after one volunteer's exclusion. Feasibility of this method was rated at 90.8 [95%CI: 89.6 - 92.4]%. The intra-observer reliability measured through Intraclass Correlation Coefficients was 0.96 [95%CI: 0.91-0.98] and 0.93 [95%CI: 0.86-0.97] depending on the operator. The inter-observer reliability was 0.89 [95%CI: 0.78-0.95]. The PS values were significantly lower in the anterior lung areas compared with the posterior areas in all breathing conditions. A weak positive correlation was found in all the lung areas when a positive end expiratory pressure was applied with r = 0.26 [95%CI: 0.12;0.39]; p < 0.01. CONCLUSION: Speckle tracking lung sliding quantification with PS was applicable in most conditions with an excellent intra- and inter-observer reliability. More studies in patients under invasive mechanical ventilation are needed to explore the correlation between PS values of pleural sliding and tidal volumes. CLINICAL REGISTRATION: NCT05415605.

Early assessment of patients with COVID-19 and dyspnea using lung ultrasound scoring. / Evaluación precoz mediante ecografía pulmonar de pacientes con disnea por COVID-19.

OBJECTIVES: The main objective was to evaluate the precision of the Modified Lung Ultrasound (MLUS score) for predicting the need for respiratory support in the first 48 hours in patients with dyspnea due to the coronavirus disease 2019 (COVID-19). The secondary objectives were 1) to compare the MLUS and National Early Warning Score 2 (NEWS2), as well as the combination of both scores, as predictors of severity according to the World Health Organization (WHO) Ordinal Scale for Clinical Improvement; and 2) to compare severity assessed by ultrasound scoring to severity assessed by lung computed tomography (CT). MATERIAL AND METHODS: Multicenter prospective observational cohort study conducted from March 30 to April 30, 2020, in 2 university hospitals. Adult patients with dyspnea due to COVID-19 were included. An initial lung ultrasound was performed, and the results of MLUS, NEW2, and lung CT evaluations were recorded. Patients were classified by risk according to the WHO scale at 48 hours, as follows: low risk (score less than 5) or high risk (score of 5 or more). RESULTS: A total of 100 patients were included: 35 (35%) were classified as low risk and 65 (65%) as high risk. The correlation between the MLUS and WHO assessments was positive and very high (Spearman rank correlation 􀁕 = 0.832; P .001). The area under the receiver operating characteristic curves of the MLUS, NEW2 and combined ultrasound scores, in relation to prediction of risk classification were, respectively, 0.96 (0.93-0.99), 0.89 (0.82-0.95) and 0.98 (0.96-1.0). The MLUS and lung CT assessments were correlated. CONCLUSION: An early lung ultrasound score can predict clinical severity in patients with dyspnea due to COVID-19.

OBJETIVO: El objetivo principal fue evaluar la precisión de la escala de ecografía pulmonar modificada (MLUS) para predecir la necesidad de soporte respiratorio en las primeras 48 horas en pacientes con disnea por COVID-19. Los objetivos secundarios fueron comparar la escala MLUS con la escala National Early Warning Score 2 (NEW2) y la combinación de ambas para predecir la gravedad según la escala de la OMS y comparar las escalas de gravedad calculadas por ecografía y tomografía computarizada (TC) pulmonar. METODO: Estudio observacional de cohortes prospectivo multicéntrico realizado desde 30 de marzo al 30 de abril de 2020 en 2 hospitales universitarios. Se incluyeron pacientes adultos con disnea por COVID-19. Se les realizó una ecografía pulmonar inicial y se calculó la escala MLUS, escala NEW2 y la escala de gravedad calculada por TC pulmonar. Los pacientes se clasificaron como de riesgo bajo (BR) si 5 puntos o de riesgo alto (AR) si 5 puntos según la escala de la OMS a las 48 horas. RESULTADOS: Se incluyeron 100 pacientes, 35 (35%) fueron de BR y 65 (65%) de AR. La correlación entre la escala MLUS y las puntuaciones de la escala ordinal de la OMS fue positiva y muy alta (rho de Spearman = 0,832; p 0,001). El área bajo la curva COR de la escala MLUS, NEW2 y combinada fue de 0,96 (0,93-0,99), 0,89 (0,82-0,95) y 0,98 (0,96-1,0), respectivamente, para predecir el grupo de RA. Hubo relación entre las escalas MLUS y lesiones pulmonares en la TC. CONCLUSIONES: Una ecografía pulmonar inicial puede predecir la gravedad clínica de los pacientes con disnea por COVID-19.

Comparative study of lung ultrasound and chest computed tomography scan in the assessment of severity of confirmed COVID-19 pneumonia.

PURPOSE: The relationship between lung ultrasound (LUS) and chest computed tomography (CT) scans in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia is not clearly defined. The primary objective of our study was to assess the performance of LUS in determining severity of SARS-CoV-2 pneumonia compared with chest CT scan. Secondary objectives were to test the association between LUS score and location of the patient, use of mechanical ventilation, and the pulse oximetry (SpO2)/fractional inspired oxygen (FiO2) ratio. METHODS: A multicentre observational study was performed between 15 March and 20 April 2020. Patients in the Emergency Department (ED) or Intensive Care Unit (ICU) with acute dyspnoea who were PCR positive for SARS-CoV-2, and who had LUS and chest CT performed within a 24-h period, were included. RESULTS: One hundred patients were included. LUS score was significantly associated with pneumonia severity assessed by chest CT and clinical features. The AUC of the ROC curve of the relationship of LUS versus chest CT for the assessment of severe SARS-CoV-2 pneumonia was 0.78 (CI 95% 0.68-0.87; p < 0.0001). A high LUS score was associated with the use of mechanical ventilation, and with a SpO2/FiO2 ratio below 357. CONCLUSION: In known SARS-CoV-2 pneumonia patients, the LUS score was predictive of pneumonia severity as assessed by a chest CT scan and clinical features. Within the limitations inherent to our study design, LUS can be used to assess SARS-CoV-2 pneumonia severity.