Pulmonary Post-Acute Sequelae of COVID-19

Introduction: Persistent symptoms have been observed in a substantial proportion of survivors of COVID-19 since relatively early in the pandemic. Among these post-acute sequelae of COVID-19 (PASC), respiratory symptoms appear to be the most prevalent. Methods: We conducted a literature review of peer-reviewed publications in English on the clinical and epidemiological features of respiratory PASC in cohorts of 100 or more patients with a follow-up of four weeks or more after acute infection. Included studies reported the prevalence of persistent respiratory symptoms and/or the results of follow-up pulmonary function tests. Results: On our review included 14 studies across eight countries with a total of 2,380 patients. Subacute PASC was reported in 876 patients, and chronic PASC in 1,504 patients. The median age ranged from 44 to 67 years. The most common symptoms observed were fatigue (44%), dyspnea (40%), and cough (22%). Lung disease as a comorbidity was found in 13% of patients on average. Predominance of males was seen in all studies of subacute PASC and six out of eight studies of chronic PASC. The rates of comorbidities for subacute vs. chronic PASC were: hypertension 32% vs. 31%, cardiovascular disease 10% vs. 7%, diabetes mellitus 15% vs. 12%, kidney disease 7% vs. 4%, and lung disease 19% vs. 10%. Conclusion: Respiratory PASC seems to be more predominant as a chronic presentation, more common in male adults, and less common in older persons. Respiratory PASC is most often associated with fatigue, dyspnea, and cough. There was no strong correlation of severity of illness, acute respiratory distress syndrome, or intensive care unit admission with respiratory PASC