Development of Pulmonary Fibrosis in Coronavirus Disease 2019 (COVID-19) Patients: A Case Series

Abstract

Introduction: SARS-CoV-2, the cause of COVID-19, was first identified in December 2019 and declared a pandemic by the WHO in March 2020. Knowledge about COVID-19 is growing exponentially, but long-term pulmonary outcomes and factors influencing the development of fibrosis, such as intubation status, remain uncertain. We present three patients with no previous underlying pulmonary disease who developed post-ARDS fibrosis secondary to COVID-19 and continue to be severely impaired six months after initial hospitalization. Case Series: Three patients developed post-ARDS pulmonary fibrosis secondary to COVID-19 within one month of acute infection. Two males and one female, aged 56 to 75, were admitted 4 to 7 days after symptom onset and required ICU admission. One patient required 12 days of mechanical ventilation and was managed with noninvasive pressure ventilation (NIPPV) for 15 days and one was managed with HFNC for 37 days. One patient receiving oxygenation via HFNC and oxymask developed pneumomediastinum on day 30 of admission and was managed conservatively. All patients demonstrated characteristic bilateral ground-glass opacities on CT chest and follow up scans showed traction-bronchiectasis with diffuse fibrotic changes. C-reactive protein level on admission ranged from 41.22 to 30.79, and all patients received systemic corticosteroids along with therapeutic anticoagulation. All patients met criteria for home oxygen on discharge. Discussion: Post-ARDS pulmonary fibrosis in COVID-19 appears to be multifactorial. Possible outcome predictors identified include: advanced age, illness severity, length of ICU stay, mechanical ventilation, smoking, and chronic alcoholism. While the mechanism remains uncertain, virus-induced cell injury and inflammatory mediators may be responsible for the accelerated lung damage observed. Management has evolved over the course of the pandemic from emphasis on early intubation to maximal use of non-invasive pressure ventilation, taking into consideration the potential harm associated with patient self-inflicted lung injury versus ventilator induced injury. Our case series demonstrates three patients with varying comorbidities and elevated inflammatory markers, who received steroids and therapeutic anticoagulation. All patients had similar clinical outcomes irrespective of intubation status. Conclusion: Intubation status did not appear to have an impact on progression to post-ARDS pulmonary fibrosis in our case series of three patients. All patients developed fibrosis and continued to experience severe dyspnea requiring home oxygen six months after acute infection. Long-term observational cohort studies are required to better establish if mechanical ventilation is a predictor of post-ARDS pulmonary fibrosis from COVID-19.