Clinical Characteristics, Respiratory Mechanics and Outcomes in Critically Ill Subjects with COVID-19 Infection in an Underserved Urban Population

Background: The COVID-19 outbreak in the United States has disproportionately affected African-Americans, but little is known about the factors that underlie this observation. Herein, we describe these associations with mortality in a largely minority underserved population.

Methods: This single center retrospective observational study included all adult subjects with laboratory confirmed SARS-Cov-2 treated in our ICU between March 15^th and May 10^th, 2020.

Results: 128 critically-ill adult subjects were included in the study (median age 68 Interquartile range(IQR) 61–76), 45% female, and 64% African-American); 124 (97%) required intubation. Eighty (63%) died during their inpatient stay, which did not differ by race/ethnicity. Compared with other racial/ethnic groups, African-Americans had a greater proportion of women (52% vs. 30%, p=0.02), and hypertensives (91% vs. 78%, p=0.035). Asthma (p=0.026) was associated with lower inpatient death, primarily among African-Americans (p=0.02). Among African-Americans, increased age (OR [95% CI]: 1.06[1.05-1.22]per year], positive fluid balance (1.06 [1.01-1.11]per 100 mL), and treatment with Tocilizumab (25.0 [3.5-180]) were independently associated with inpatient death, while higher platelets (0.65 [0.47-0.89]per 50 x 10³/ml) and treatment with intermediate dose anticoagulants (0.08 [0.02, 0.43]) were protective. Among other race/ethnic groups, higher total bilirubin (1.75 [0.94, 3.25]per 0.2 mg/dL) and higher maximal lactate (1.43 [0.96, 2.13]per mmol/L) were marginally associated with increased death, while Tocilizumab treatment was marginally protective (0.24 [0.05, 1.25]). During first 72 hours of ventilation, those who died had less increase in PaO2/FiO2 (p=0.046), and less reduction in positive end-expiratory pressure (PEEP) (p=0.01), and FiO₂ requirement (p=0.002); these patterns did not differ by race/ethnicity.

Conclusions: African-American and other race/ethnicity subjects had similar mortality rates from Covid-19, but differed in factors that were associated with increased risk of death. In both groups, subjects who died were older, had a positive fluid balance and less improvement of PaO2/FiO2 ratio, PEEP, and FiO₂ requirement on ventilation.