Follow-up evaluation of pulmonary function and computed tomography findings in chronic kidney disease patients after COVID-19 infection

Abstract

Pulmonary complications are common after SARS-CoV2- infection. However, data on pulmonary sequelae of COVID-19 after recovery in dialysis patients are limited. We determined the prevalence of abnormal lung function tests and CT findings and investigate the association factors impacting pulmonary dysfunction. This prospective observational cohort study enrolled 100 patients with stage 5 chronic kidney disease (CKD) undergoing dialysis who had recovered from COVID-19 for ≥3 months. Pulmonary function test (PFT) and chest computed tomography (CT) were performed. Demographic data and laboratory results were recorded. The mean patient age was 55.15 ± 12.84 years. Twenty-one patients (21%) had severe COVID-19, requiring mechanical ventilation or oxygen supplementation. Pulmonary function tests revealed a restrictive pattern in 41% (95% confidence interval [CI], 31.73-50.78;) and an obstructive pattern in 7.29% (95% CI, 3.19-13.25) patients. The severe group showed PFT test results similar to the non-severe group, with three patients showing severe obstructive lung disease. The CT scan findings included reticulation (64%), multifocal parenchymal band (43%), ground glass opacities (32%), and bronchiectasis (28%). The median total CT score was 3 (interquartile range, 1-8.5). The CT score and PFT findings showed no association with pulmonary dysfunction extent, except in bronchiectasis. Lung function indices were associated with abnormal CT findings. Abnormal CT findings (bronchiectasis, reticulation, and ground-glass opacities) was associated with higher oxygen requirements than normal CT findings (p = 0.008, bronchiectasis; p = 0.041, reticulation; p = 0.032, ground-glass appearance). Aside from CT findings and CRP levels, no significant lung abnormalities were observed in severe and non-severe patients. Some patients had residual symptoms at follow-up. The findings indicate persistence of both radiological and physiological abnormalities in dialysis patients after COVID-19. However, the prevalence of these abnormalities was comparable to that in the normal population; few patients experienced ongoing symptoms. Follow-up observations and evaluations are warranted. Trial registration. Clinicaltrials.gov Identifier: NCT05348759.

Fig 1. Follow-up pulmonary function test three months post COVID-19 recovery.

Fig 2. Radiological changes after COVID-19.

A: Coronal (A) and axial (B) computed tomography (CT) in lung window showing evidence of bronchiectasis at basal segment of left lower lobe. B: Axial computed tomography (CT) in lung window showing evidence of ground-glass opacity at posterior aspect of both lower lungs. C: Axial computed tomography (CT) in lung window showing band-like parenchymal opacity at posterior aspect of right basal lung. D: Axial computed tomography (CT) in lung window showing reticulation at both basal lung.

Fig 3. Symptoms after COVID-19 infection.

Out of 100 patients, 21 patients had one or more ongoing respiratory symptoms (dyspnea, cough, or other). Six patients had persistent cough, 14 patients had dyspnea, four had both cough and dyspnea,and one patient had other symptoms.