Impact of Respiratory Support During Hospitalization on Functional Outcomes in Long COVID: A Post-Hoc Analysis of a Prospective Cohort Study

Post-acute COVID-19 syndrome (PACS) is characterized by the persistence of one or more symptoms after the acute phase, leading to physical disabilities. This study aims to investigate whether the functional capacity and respiratory function 120 days post-COVID-19 differed according to the level of respiratory support needed during hospitalization in acute COVID-19 in the pre-vaccine rollout period. We followed up with 118 COVID-19 hospitalized patients in the acute phase until 120 days post-acute disease, with patients split into a Non-Invasive Oxygen Therapy Group (OTG, n = 72), Invasive Mechanical Ventilation Group (IMV, n = 12), and Room Air Group (RAG, n = 34), assessing the body composition, respiratory muscle strength, pulmonary function, functional capacity, and muscle strength at the follow-up visit. In total, 54 individuals (45.8%) were female, with a median age of 48 years old (IQR: 41-58). We found that the group with IMV was older (<i>p</i> < 0.001), had more admissions to the ICU (<i>p</i> < 0.001), and had longer hospital stays (<i>p</i> < 0.001). There were no statistically significant differences between groups (OTG, IMV, and RAG) for the spirometry function (<i>p</i> = 0.31), DASI score (<i>p</i> = 0.77), manovacuometry (MIP <i>p</i> = 0.74; MEP <i>p</i> = 0.23), 6MWT (<i>p</i> = 0.43), and handgrip (<i>p</i> = 0.19) outcomes. At D120, the IMV group had an important loss of body muscle mass (BMM) and a higher BMM than RAG (<i>p</i> = 0.02). Reduction in MIP (<i>p</i> = 0.01) and MEP (<i>p</i> = 0.02) in the IMV group and OTG group when compared to the RAG was also observed. Functional outcomes at 120 days from COVID-19 hospitalization were not found to be associated with the levels of oxygen supplementation during acute disease in this group of participants.