Pulmonary function test and computed tomography features during follow-up after SARS, MERS and COVID-19: a systematic review and meta-analysis

Abstract

BackgroundThe COVID-19 pandemic follows SARS and MERS coronavirus epidemics. Some survivors of COVID-19 infection experience persistent respiratory symptoms, yet their cause and natural history remains unclear. Follow-up after SARS and MERS may provide a model for predicting the long-term pulmonary consequences of COVID-19.MethodsThis systematic review and meta-analysis aims to describe and compare the longitudinal pulmonary function test (PFT) and computed tomography (CT) features of patients recovering from SARS, MERS and COVID-19. Meta-analysis of PFT parameters (DerSimonian and Laird random effects model) and proportion of CT features (Freeman-Tukey transformation random effects model) were performed.FindingsPersistent reduction in the diffusing capacity for carbon monoxide (DLco) following SARS, and COVID-19 infection is seen at 6 months follow-up and 12 months after MERS. Other PFT parameters recover in this time. 6 months after SARS and COVID-19, ground-glass opacity (GGO), linear opacities and reticulation persist in over 30% of patients; honeycombing and traction dilatation reported less. Severe/ critical COVID-19 infection leads to greater CT and PFT abnormality compared to mild/ moderate infection.InterpretationPersistent diffusion defects suggestive of parenchymal lung injury occur after SARS, MERS and COVID-19 infection, but improve over time. After COVID-19 infection, CT features are suggestive of persistent parenchymal lung injury, in keeping with a post-COVID-19 interstitial lung syndrome (PCOILS) – it is yet to be determined if this is a regressive or progressive disease.

Pulmonary Recovery 12 Months after Non-Severe and Severe COVID-19: The Prospective Swiss COVID-19 Lung Study

“…Our results are in line with the first meta-analysis comparing lung function and radiological patterns over time after infection with SARS-CoV-2, severe acute respiratory syndrome virus, and Middle East respiratory syndrome virus [17]. Other studies showed that at 3 months, 42% of patients that had not required mechanical ventilation [18] and 82% of those that had COVID-19-related ARDS [19] displayed decreased DLCO.…”

The prevalence and long-term health effects of Long Covid among hospitalised and non-hospitalised populations: a systematic review and meta-analysis

“…5,7,8 Changes in pulmonary function are similar to those observed following other viral infections including SARS and MERS. 15 Even when excluding studies with less than 100 patients and those in specialist populations, variability in estimated prevalence between studies remained high, particularly in the non-hospitalised cohort. In addition to varying study designs, different follow-up measurement tools and a wide range of follow-up durations, observed heterogeneity between studies may be explained by the lack of standardised data collection tools, particularly in studies of non-hospitalised populations.…”

Electrical Impedance Tomography (EIT) in a Patient Suffering from Post-COVID Syndrome with Dyspnea: A Case Report

“…Furthermore, experience with patients suffering from persistent dyspnea after SARS-CoV-2 infection often shows no impairment in lung function and computed tomography [ 5 ]. Because of the limited experience with EIT in spontaneously breathing patients with post-COVID syndrome, it would be desirable to combine EIT with pulmonary function tests (PFT) [ 20 ], which are the gold standard, and cardiopulmonary exercise testing [ 21 ] on the same day.…”