Introduction

: At the beginning of the SARS-CoV-2 pandemic, acute respiratory failure has been the most important cause of hospitalization in patients with COVID-19, being more severe in patients with comorbidi ties and risk factors. In these scenarios hypoxemia has been associated with increased mortality. Our objective was to identify parameters obtained from arterial blood gases (ABG) associated with mortality in patients with COVID-19 at hospital admission.

Methods

: GSA samples obtained by breathing room air (FiO2 21%) processed in the clinical laboratory were retrospectively studied in an ABL90 flex analyzer (Radi ometer).

Results

: Acute respiratory alkalosis was the predomi nant acid-base disturbance. Considering those patients with respiratory failure (paO2 <60 mmHg), “silent” hypox emia was observed in 11/176 (6%) of studied patients.

In a multivariate analysis, three gasometric parameters at admission showed a positive association with hos pital mortality: paO2 (p=0.053), paO2/pO2e index (which expresses the paO2 adjusted to the paO2 expected for age) (p=0.047) and fractional saturation of hemoglobin (OxiHb%) (p=0.028).

Discussion

: GSA generate a key contribution in un derstanding the pathophysiology of the COVID-19 pa tient: in the initial evaluation, monitoring and prognosis of this disease.