Ultrasound assessment of pulmonary fibroproliferative changes in severe COVID-19: a quantitative correlation study with histopathological findings

Abstract

This study was designed to evaluate the usefulness of lung ultrasound (LUS) imaging to characterize the progression and severity of lung damage in cases of COVID-19. Methods:We employed a set of combined ultrasound parameters and histopathological images obtained simultaneously in 28 patients (15 women, 0.6-83 years) with fatal COVID-19 submitted to minimally invasive autopsies, with different times of disease evolution from initial symptoms to death (3-37 days, median 18 days). For each patient, we analysed eight post-mortem LUS parameters and the proportion of three histological patterns (normal lung, exudative diffuse alveolar damage [DAD] and fibroproliferative DAD) in eight different lung regions. The relationship between histopathological and post-mortem ultrasonographic findings was assessed using various statistical approaches.Results: Statistically significant positive correlations were observed between fibroproliferative DAD and peripheral consolidation (coefficient 0.43, p = 0.02) and pulmonary consolidation (coefficient 0.51, p = 0.005). A model combining age, time of evolution, sex and ultrasound score predicted reasonably well (r = 0.66) the proportion of pulmonary parenchyma with fibroproliferative DAD. Conclusion:The present study adds information to previous studies related to the use of LUS as a tool to assess the severity of acute pulmonary damage. We provide a histological background that supports the concept that LUS can be used to characterize the progression and severity of lung damage in severe COVID-19.

Low Dose Chest CT and Lung Ultrasound for the Diagnosis and Management of COVID-19

“…Although LUS is not recommended as the imaging technique of choice for screening and diagnosing COVID-19 pneumonia, it has demonstrated its ability to assess the anatomical severity of pulmonary lesions [50] in the ED and the ICU in order to help in medical triage. This is consistent with autopsy results in 28 patients with fatal COVID-19 infection after ARDS showing that the severity of post-mortem LUS findings was correlated with the proportion of diffuse alveolar damage on lung histopathological analysis [59].…”

Point-of-care ultrasonography for risk stratification of non-critical suspected COVID-19 patients on admission (POCUSCO): a prospective binational study

“…[29] L-POCUS would provide an effective estimate of the extent of the pulmonary histological damage. [30] To our knowledge, only one previous study assessed the performance of L-POCUS in identifying patients with suspected or confirmed COVID-19 at risk of deteriorating. Indeed, Bonadia et al conducted a prospective study in 41 COVID-19 patients and showed the higher the rate, the higher the in-hospital mortality and need for intensive care admission.…”

“…[29] L-POCUS would provide an effective estimate of the extent of the pulmonary histological damage. [30]…”

Can lung ultrasound predict histologic pattern of lung injury in critically ill patients with COVID-19? Author’s reply

“…We thank the comments and suggestions in the letter by Avdeev et al [1] addressing our recent article published in Intensive Care Medicine [2]. Indeed, as pointed out in the original article, we have limitations in our study since we only dealt with the most severe presentation of pulmonary coronavirus disease 2019 (COVID-19), that is, the fatalities.…”

“…It is expected that part of the fibroproliferative changes in COVID-19-related acute respiratory distress syndrome (ARDS) undergo some regression in survivors. Severe COVID-19 pneumonia is a disease characterised by a simultaneous combination of acute and fibroproliferative changes [2,3]; in our study, the fibroproliferative pattern was defined as any degree of fibroblastic proliferation within the interstitium and alveolar spaces, including presence of loose aggregates of fibroblasts, collagen deposition, squamous metaplasia, and possible remnants of hyaline membranes [2]. In a larger series of 41 COVID-19 autopsies, we showed that a more advanced fibrotic pattern of pulmonary lesion is present in 39% of the patients and is associated with longer periods of hospitalisation [3].…”