Clinical and laboratory characteristics of critically ill COVID-19 patients with chronic lung disease

INTRODUCTION: Chronic lung diseases (CLD) are associated with increased susceptibility to respiratory infections and may influence COVID-19 outcomes. This research aims to assess the clinical, laboratory findings, and prognostic outcomes in critically ill COVID-19 patients with and without CLD, and to explore differences between various CLD types. METHODOLOGY: A retrospective analysis was conducted on 406 critically ill COVID-19 patients, comparing those with CLD and those without. Clinical characteristics, laboratory markers, and mortality rates were assessed. Subgroup analyses evaluated differences between COPD, asthma, and other CLD types. RESULTS: Patients with CLD were older and had significantly lower lymphocyte and platelet levels than those without CLD (p values were 0.034, 0.021, and 0.013, respectively). The mean age, urea level, and platelet count in the COPD group showed significant differences compared to the other groups. Among critically ill COVID-19 patients, mortality rates were observed to be higher in the CLD group compared to those without CLD, and in the COPD group compared to other CLD types; however, these differences did not reach statistical significance. Systemic steroid use was associated with reduced 3-month (OR: 0.403, 95% CI: 0.226-0.719, p = 0.002) and 1-year mortality (OR: 0.513, 95% CI: 0.288-0.914, p = 0.023). Inhaled corticosteroid use did not increase mortality and was predominantly utilized for symptom management. Laboratory markers such as lymphopenia and thrombocytopenia were significantly associated with worse outcomes. CONCLUSIONS: CLD and its subtypes were not independently linked to mortality in critically ill COVID-19 patients; however, their association with older age and worse laboratory profiles highlights their clinical significance.