Procalcitonin levels in COVID-19 patients are strongly associated with mortality and ICU acceptance in an underserved, inner city population

ABSTRACT

Rationale The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes COVID-19, has led to a global health crisis unlike any our contemporaries have witnessed before. SUNY Downstate Health Sciences University was designated as one of three COVID-19-only hospitals on March 28, 2020. This retrospective, single-center observational study grants a unique perspective surrounding the experience of the critical care service at a public institution serving a predominantly Afro-Caribbean, inner city population. Methods: Between March 11 and April 30, 2020, the critical care service was consulted for a total of 271 COVID-19 patients. We queried the electronic medical record for patient visits with critical care consult notes and collected data on demographics, comorbidities, ICU acceptance, treatment strategies, and clinical outcomes. Non-COVIDrelated consults were excluded. Chi-squared tests compared categorical variables, and independent samples ttest assessed differences in continuous variables based on mortality and ICU admission status. Logistic regression models determined if various factors independently predicted the odds of mortality. We conducted retrospective analyses to identify factors associated with survival and ICU acceptance. Results: Of the 271 patients with critical care consults, 33% (n=89) survived and 67% (n=182) expired. At the bivariate level, age, BUN, and neutrophil percentage were significantly associated with mortality, with age showing the strongest correlation (age survivors, 61.62±1.50 vs. non-survivors, 68.98±0.85, p<0.001). There was a significant association between neutrophil percentage and mortality in the univariate logistic regression model (Q4 vs. Q1, OR 2.73, 95% CI (1.28-5.82), p trend = 0.044). In the multivariate analyses, procalcitonin exhibited a positive correlation with the odds of mortality, adjusting for age, sex, and race/ethnicity (procalcitonin Q4 vs. Q1, OR 5.65, 95% CI (2.14-14.9), p trend <0.001). Adjusting for the same covariates, platelets exhibited a negative correlation with the odds of mortality (Q4 vs. Q1, OR 0.47, 95% CI (0.22-0.998), p trend = 0.010). Interestingly, of these factors, only elevated procalcitonin levels were associated with an increased likelihood of ICU acceptance. Conclusions: This retrospective, observational study during the first peak of the COVID-19 pandemic identified key factors linked to disease severity and outcomes. Of note, procalcitonin was the factor most strongly associated with both mortality and likelihood of ICU acceptance at the bivariate level. Respiratory failure is the primary cause of death in COVID-19, and our data suggests that procalcitonin is a useful marker that accurately reflects the severity of lung involvement during SARS-CoV-2 infection.