High-flow nasal cannula therapy in a predominantly African American population with COVID-19 associated acute respiratory failure.

IMPORTANCE: Use of non-invasive respiratory modalities in COVID-19 has the potential to reduce rates of intubation and mortality in severe disease however data regarding the use of high-flow nasal cannula (HFNC) in this population is limited. OBJECTIVE: To interrogate clinical and laboratory features of SARS-CoV-2 infection associated with high-flow failure. DESIGN: We conducted a retrospective cohort study to evaluate characteristics of high-flow therapy use early in the pandemic and interrogate factors associated with respiratory therapy failure. SETTING: Multisite single centre hospital system within the metropolitan Detroit region. PARTICIPANTS: Patients from within the Detroit Medical Center (n=104, 89% African American) who received HFNC therapy during a COVID-19 admission between March and May of 2020. PRIMARY OUTCOME: HFNC failure is defined as death or intubation while on therapy. RESULTS: Therapy failure occurred in 57% of the patient population, factors significantly associated with failure centred around markers of multiorgan failure including hepatic dysfunction/transaminitis (OR=6.1, 95% CI 1.9 to 19.4, p<0.01), kidney injury (OR=7.0, 95% CI 2.7 to 17.8, p<0.01) and coagulation dysfunction (OR=4.5, 95% CI 1.2 to 17.1, p=0.03). Conversely, comorbidities, admission characteristics, early oxygen requirements and evaluation just prior to HFNC therapy initiation were not significantly associated with success or failure of therapy. CONCLUSIONS: In a population disproportionately affected by COVID-19, we present key indicators of likely HFNC failure and highlight a patient population in which aggressive monitoring and intervention are warranted.

Preexisting respiratory diseases and clinical outcomes in COVID-19: a multihospital cohort study on predominantly African American population.

BACKGROUND: Comorbidities play a key role in severe disease outcomes in COVID-19 patients. However, the literature on preexisting respiratory diseases and COVID-19, accounting for other possible confounders, is limited. The primary objective of this study was to determine the association between preexisting respiratory diseases and severe disease outcomes among COVID-19 patients. Secondary aim was to investigate any correlation between smoking and clinical outcomes in COVID-19 patients. METHODS:  This is a multihospital retrospective cohort study on 1871 adult patients between March 10, 2020, and June 30, 2020, with laboratory confirmed COVID-19 diagnosis. The main outcomes of the study were severe disease outcomes i.e. mortality, need for mechanical ventilation, and intensive care unit (ICU) admission. During statistical analysis, possible confounders such as age, sex, race, BMI, and comorbidities including, hypertension, coronary artery disease, congestive heart failure, diabetes, any history of cancer and prior liver disease, chronic kidney disease, end-stage renal disease on dialysis, hyperlipidemia and history of prior stroke, were accounted for. RESULTS:  A total of 1871 patients (mean (SD) age, 64.11 (16) years; 965(51.6%) males; 1494 (79.9%) African Americans; 809 (43.2%) with ≥ 3 comorbidities) were included in the study. During their stay at the hospital, 613 patients (32.8%) died, 489 (26.1%) needed mechanical ventilation, and 592 (31.6%) required ICU admission. In fully adjusted models, patients with preexisting respiratory diseases had significantly higher mortality (adjusted Odds ratio (aOR), 1.36; 95% CI, 1.08-1.72; p = 0.01), higher rate of ICU admission (aOR, 1.34; 95% CI, 1.07-1.68; p = 0.009) and increased need for mechanical ventilation (aOR, 1.36; 95% CI, 1.07-1.72; p = 0.01). Additionally, patients with a history of smoking had significantly higher need for ICU admission (aOR, 1.25; 95% CI, 1.01-1.55; p = 0.03) in fully adjusted models. CONCLUSION:  Preexisting respiratory diseases are an important predictor for mortality and severe disease outcomes, in COVID-19 patients. These results can help facilitate efficient resource allocation for critical care services.