ABSTRACT
Background: COVID-19-related lung injury may persist or require time to recover in some individuals. Objective(s): To better understand the post-acute pathophysiology of non-critical COVID-19 by evaluating respiratory system resistance and reactance in COVID-19 survivors 4-weeks and 6-months after recovery, compared to neverCOVID-19 controls. Method(s): Individuals with no history of lung disease who were hospitalized or home-isolated during the acute-phase of COVID-19, and age-matched never-COVID-19 controls, performed respiratory oscillometry (tremoFlo C-100) to measure resistance (Rrs5Hz, Rrs19Hz , Rrs5-19Hz ), reactance (Xrs5Hz ) and area of reactance (A ), Six Minute Walk Test, and completed the Borg Dyspnea Scale 4-weeks (visit 1) and 6-months (visit 2) post-recovery. Result(s): Hospitalized (n=9), home-isolated (n=20) and never-COVID-19 (n=17) cohorts were similar with respect to age (p=0.12), sex (p=0.89), and BMI (p=0.08). Figure 1 shows that Rrs5-19Hz (p=0.04) and A (p=0.009) were higher, and Xrs5Hz (p=0.007) was more negative, in the hospitalized cohort compared to control cohort at visit 1, but not visit 2. These measures were associated with greater dyspnea and decreased six-minute walk distance. Conclusion(s): Increased peripheral resistance and reactance following recovery from non-critical COVID-19 may only be prevalent among hospitalized COVID-19 survivors, within which these respiratory abnormalities may be temporary.