Post-discharge chest CT findings and pulmonary function tests in severe COVID-19 patients

Abstract

To evaluate chest computed tomography (CT) and pulmonary function test (PFT) findings in severe COVID-19 patients after discharge and correlate CT pulmonary involvement with PFT results. Methods: COVID-19 patients admitted to our hospital between February 25 and May 2, 2020, were retrospectively included according to the following criteria: (a) COVID-19 defined as severe based on the WHO interim guidance (i.e., clinical signs of pneumonia plus respiratory rate > 30 breaths/min, severe respiratory distress, and/or SpO 2 < 90 % on room air); (b) chest radiograph in the acute setting; (c) post-discharge unenhanced chest CT; and (d) post-discharge comprehensive PFT. Imaging findings were retrospectively evaluated in consensus by two readers, and volume of abnormal lung was measured on CT using 3D Slicer software. Differences between demographics, comorbidities, acute radiographic findings, PFT, and post-discharge clinical and laboratory data of patients with normal and abnormal CT findings were assessed by Mann-Whitney or Fisher tests, and the compromised lung volume-PFT association by Pearson correlation after removing possible outliers. Results: At a median of 105 days from symptom onset, 74/91 (81 %) patients had CT abnormalities. The most common CT pattern was combined ground-glass opacity and reticular pattern (46/74, 62 %) along with architectural distortion (68/74, 92 %) and bronchial dilatation (66/74, 89 %). Compromised lung volume had a median value of 15 % [11-23], was higher in dyspneic patients, and negatively correlated with the percentage of predicted DLCO, VA, and FVC values (r = -0.39, -0.5, and -0.42, respectively). These PFT parameters were significantly lower in patients with CT abnormalities. Impairment of DLCO and KCO was found in 12 (13 %) cases, possibly implying an underlying pulmonary vasculopathy in this subgroup of patients. Conclusions: Most severe COVID-19 survivors still had physiologically relevant CT abnormalities about three months after the disease onset, with an impairment of diffusion capacity on PFT. A pulmonary vasculopathy was suggested in a minor proportion of patients.

COVID-19 pneumonia imaging follow-up: when and how? A proposition from ESTI and ESR

“…CT features at three months At 3 months, there are remaining CT abnormalities reported in 17 to 91% of discharged COVID-19 pneumonia patients [13,[24][25][26][27]. The highest range was reported in patients who were admitted to ICU [28], while it is expected that patients with minor signs of acute pneumonia might reverse in the vast majority of cases.…”

“…Low-attenuation GGO remains the most frequent CT finding, observed in up to two-third or more of patients [13,[24][25][26]. Other CT findings include linear consolidation or band-like and perilobular opacities, possibly in part consistent with organizing pneumonia, and also reticulation and interstitial thickening (Figs.…”

Post-Acute COVID-19 Syndrome for Anesthesiologists: A Narrative Review and a Pragmatic Approach to Clinical Care

“…Functional evaluation of lung disease commonly revealed reduced diffusion capacity for carbon monoxide (DLCO), with a range between 21-50% of patients. 57,58,88 Moreover, female sex and an ICU admission were found to be risk factors for DLCO <60% of predicted at 4 months. 58 Other notable spirometry findings included mixedrestrictive flow patterns and impaired alveolar volume on spirometry.…”

“…56 Radiographically, multiple reports note abnormal chest x-rays and computed tomography (CT) scans on 3-6-month follow-ups, with ground-glass opacities and architectural distortion being the most common. 54,57,75,76 These findings on CT scan are also correlated with abnormal pulmonary function test results. Functional evaluation of lung disease commonly revealed reduced diffusion capacity for carbon monoxide (DLCO), with a range between 21-50% of patients.…”

Computed tomography after severe COVID-19 pneumonia: findings at 6 months and beyond

“…Fifteen to 30% of patients develop acute respiratory distress syndrome (ARDS) requiring hospitalization in intensive care units (ICU) and mechanical ventilation [2,3]. At 3 months, there are persisting CT abnormalities in 17 to 91% of discharged COVID-19 patients [4][5][6][7][8], mainly consistent with an organizing pneumonia pattern. These anomalies are more frequently reported in patients who were admitted to ICU [9].…”