Respiratory manifestations of long COVID

Abstract As we near the third year of the COVID-19 pandemic, greater attention is now being paid to the potential long-term consequences of SARS-CoV-2 in the hundreds of millions of people infected globally. A syndrome termed “long COVID” has emerged, which predominantly manifests as persistent fatigue, dyspnea, chest pain, and cognitive dysfunction following acute infection. The incidence of long COVID is in the range of 15% based on current best evidence, and symptoms are likely a result of several different pathophysiological mechanisms including multi-organ injury from acute infection, systemic viral persistence, immune dysregulation, and/or autoimmunity. Pulmonary symptoms represent a significant component of long COVID, and there is a growing body of research describing the epidemiology, risk factors, physiology, and radiology of the respiratory manifestations of long COVID. In this clinical review, we examine the most recent evidence relating to “respiratory long COVID,” discuss how innovative technologies such as Xenon-129 gas transfer magnetic resonance imaging (MRI) and respiratory oscillometry are helping to elucidate its unique pathophysiology, and consider the role of preventative strategies and possible treatments such as adapted pulmonary rehabilitation. The burden of respiratory long COVID is likely to continue to grow, and all healthcare professionals who care for patients with respiratory disease must prepare for this emerging chronic condition. This will require increased resources from healthcare decision makers, inventive approaches to healthcare delivery, further research, and the same spirit of collaboration that has enabled the many success stories to date in the global effort against COVID-19.