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. 2022;101(7):632-637.
doi: 10.1159/000522275. Epub 2022 Mar 15.

Early Variation of Respiratory Indexes to Predict Death or ICU Admission in Severe Acute Respiratory Syndrome Coronavirus-2-Related Respiratory Failure

Giorgio Maraziti  1 , Cecilia Becattini  1
Affiliations

Early Variation of Respiratory Indexes to Predict Death or ICU Admission in Severe Acute Respiratory Syndrome Coronavirus-2-Related Respiratory Failure

Giorgio Maraziti et al. Respiration. 2022.

Abstract

Background: In severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-related respiratory failure, the prognostic value of clinically based or blood-gas-based respiratory indexes is unclear.

Objectives: We aimed to assess the prognostic value of Respiratory Index (RI, oxygen saturation [SpO2]/respiratory rate [RR]), RR-oxygenation index (ROX, SpO2/fraction of inspired oxygen [FiO2]/RR), partial pressure of oxygen (PaO2)/FiO2 ratio (P/F), or standard PaO2/FiO2 ratio (STP/F) at admission and of their variation during hospitalization in SARS-CoV-2-related respiratory failure.

Methods: In 100 consecutive patients hospitalized due to SARS-CoV-2-related respiratory failure, we assessed the association of RI, ROX, P/F and STP/F, and death; secondary outcome was the composite of 7-day death or intensive care unit (ICU) admission.

Results: ROX <3.85 at admission (hazard ratio [HR] 2.95, 95% confidence interval [CI] 1.29-6.77) and decreasing RI or P/F during hospitalization (RI: HR 1.05, 95% CI: 1.00-1.09; P/F: HR 1.01, 95% CI: 1.00-1.02) were predictors of in-hospital death. RI ≤3.8, ROX <3.85, and P/F <100 at admission were predictors for death or ICU admission (RI: HR 3.77, 95% CI: 1.30-10.98; ROX: HR 4.56, 95% CI: 1.90-10.96; P/F: HR 7.37, 95% CI: 1.59-34.2). The decrease of RI (HR 1.14, 95% CI: 1.03-1.25), ROX (HR 1.45, 95% CI: 1.11-1.88), P/F (HR 1.08, 95% CI: 1.01-1.15), or STP/F (HR 1.05, 95% CI: 1.01-1.08) during hospitalization was associated with 7-day death or ICU admission.

Conclusions: In patients with SARS-CoV-2-related respiratory failure, easy-to-calculate clinically based respiratory indexes at admission and their variation during hospital stay can be used to assess and monitor the risk for death or ICU admission.

Keywords: COVID-19; Respiratory distress syndrome; Respiratory insufficiency; Respiratory rate.

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Conflict of interest statement

The authors have no conflicts of interest to declare.

Figures

Fig. 1
Fig. 1
Receiver operating characteristic for respiratory indexes at admission and in-hospital death. RI, respiratory index; P/F, PaO2/FiO2 ratio; STP/F, standard P/F ratio; ROX, RR-oxygenation index.
See this image and copyright information in PMC

Comment in

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