Analysis of clinical symptoms, radiological changes and pulmonary function data 4 months after COVID‐19

Abstract

Background Coronavirus disease 2019 (COVID‐19) ranges from asymptomatic disease to respiratory failure and requires invasive mechanical ventilation (IMV). Data about the sequelae after infection are scarce. The study aims to describe the prevalence of symptoms, pulmonary function tests (PFTs), and radiological changes after four months of follow‐up. Methods A prospective, cross‐sectional, multicentre study was performed. Patients with different illness severities were consecutively included (mild; moderate: hospitalized without IMV; severe: hospitalized with IMV). Clinical variables, health‐related quality of life (HRQoL), PFT (spirometry, diffusing capacity of the lungs for carbon monoxide (DLCO)), and (CT) scans of the chest were obtained. The association between the risk of sequelae (DLCO <80%) and altered CT was analysed using logistic regression adjusted for confounding variables. Results 60 patients (18 mild, 17 moderate, and 25 severe) were included. Fatigue was found in 11% of the mild, 47% of the moderate and 36% of the severe group. Altered DLCO (mild: 5.5%, moderate: 41%, severe: 28%, p < .05) and change in HRQoL (mild: 50%, moderate: 94%, severe: 60%), while the severe group showed a higher prevalence of altered CT (88% vs. 64%). Awake prone position (APP) and high‐flow nasal cannula (HFNC) was independently associated with altered DLCO, Odds ratio (OR) 7.28 (CI, 1.10‐47.81; p < .05), and altered CT, OR 9.50 (CI, 1.26‐71.5; p < .05). Besides, prolonged time in IMV was associated with altered CT, OR 1.24 (CI, 1.05‐1.46; p < .05). Discussion It is common to find sequelae in symptoms, radiology, and PFT. In our series, the use of APP+HFNC and days on IMV were associated with an increased risk of sequelae.

Risk factors for impaired pulmonary diffusion function in convalescent COVID-19 patients: A systematic review and meta-analysis

“…In most studies, the diagnostic criterion for the impairment of DLCO was DLCO < 80% of predicted. 17 , 25 , 26 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 Except for the study performed by Ayad Mohammed Salem, 41 the diagnostic criterion was DLCO < 75% of predicted. There were 100% follow-up rates in 14 studies, 17 , 26 , 27 , 28 , 29 , 30 , 33 , 34 , 35 , 36 , 37 , 38 , 40 , 41 90% in two studies 31 , 32 , 51% in one study 25 and 87.3% in one study 39 Seventeen studies 17 , 25 , 26 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 have reported 14.3% to 67% COVID-19 survivors with impaired diffusing capacity for carbon monoxide.…”

“…All of the 18 included studies are observational studies, of which 16 are cohort studies, 17 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 one is a prospective, cross-sectional study 40 and one is a cross-sectional case-control study. 41 The included studies were published between 2020 and 2021 and were conducted in seven countries including China, Germany, Italy, Spain, Chile, Norway and Saudi Arabia.…”

“…17 papers 17 , 25 , 26 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 reported risk factors associated with DLCO impairment and 12 studies were included in the meta-analysis. 17 , 25 , 26 , 28 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 One mentioned risk factor for diffusion capacity for nitric oxide (DLNO) impairment. 27 Due to insufficient data and uncertain definitions of DLNO and Restrictive Pattern, this review focuses on a meta-analysis of risk factors for impaired DLCO.…”

“…All selected studies were assessed for methodological quality with NOS. The NOS score of 12 studies included in the meta-analysis was 7.6 (IQR: 7.0–9.0), indicating that all included studies were of high (50%) 17 , 25 , 26 , 28 , 34 , 41 or moderate (50%) 35 , 36 , 37 , 38 , 39 , 40 quality literature. The quality of evidence (GRADE) in the analyzed studies was “low” or “very low”.…”

“…A total of ten literature data reported the association between older age and impaired DLCO. 25 , 26 , 28 , 34 , 35 , 36 , 37 , 39 , 40 , 41 One study was excluded because it was discussed in two age groups (age < 60 and age≥60). 39 Finally, eight articles were included for meta-analysis after excluding one study 36 by performing sensitivity analysis (e-Figures 4-5).…”