UNLABELLED

Critically ill patients with COVID-19 experience high rates of delirium and coma. Whether delirium occurs through novel mechanisms in COVID-19 is not known. We analyzed the relationship among biomarkers of inflammation (C-reactive protein [CRP]), hypercoagulability (d-dimer), and lung macrophage activation (ferritin), and the primary composite outcome of delirium/coma next day. We also measured associations between biomarkers and next day delirium and coma independently, and delirium severity.

DESIGN

Retrospective, observational cohort study.

SETTING

ICUs at two large, urban, academic referral hospitals.

PATIENTS

All consecutive adult patients admitted to the ICU from March 1, 2020, to June 7, 2020, with COVID-19 with clinical biomarkers and delirium assessments performed.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Daily concentrations of CRP, d-dimer, and ferritin were obtained. Coma (assessed by Richmond Agitation-Sedation Scale) and delirium (assessed by Confusion Assessment Method for the ICU/Confusion Assessment Method for the ICU-7) were measured bid. A cohort of 197 ICU patients with COVID-19 were included. Higher d-dimer (odds ratio [OR], 1.57; 95% CI, 1.17-2.12; < 0.01) and ferritin quartiles (OR, 1.36; 95% CI, 1.02-1.81; < 0.01) were associated with greater odds of the composite outcome of delirium/coma next day. d-dimer was associated with greater odds of next day delirium (OR, 1.49; 95% CI, 1.14-1.94; < 0.01) and coma independently (OR, 1.52; 95% CI, 1.08-2.14; = 0.017). Higher ferritin quartiles were associated with greater odds of next day delirium (OR, 1.33; 95% CI, 1.04-1.70; = 0.026) and coma independently (OR, 1.59; 95% CI, 1.14-2.23; < 0.01). Higher CRP quartiles were associated with coma (OR, 1.36; 95% CI, 1.03-1.79; = 0.030) and delirium severity the next day (β = 0.30; se, 0.07; ≤ 0.01).

CONCLUSIONS

Our hypothesis-generating study found d-dimer and ferritin were associated with delirium/coma the following day, as well as delirium and coma independently. CRP was associated with next day coma and delirium severity. Larger studies to validate these results are needed.