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[This article belongs to Volume - 70, Issue - 8]
Published on : 2025-08-11 20:53:50
Article Code: AMJ-11-08-2025-12327
Title : Correlation Of SpO2/FiO2 To PaO2/FiO2 In Patients With Acute Hypoxemic Respiratory Failure
Author(s) : Hassanain Qahtan Mohammed Albayati, Waleed Ibrahim Al-Ansari, Alhussein Mohammed Saleh Alhaddad, Mar AlMashhadani
Abstract :
Acute hypoxemic respiratory failure (AHRF) is very common presentation with high risk of mortality and morbidity.
Acute respiratory distress is one of the main causes of AHRF, it is often difficult to differentiate between ARDS and
non-ARDS hypoxemia cases. The definition of ARDS requires the partial pressure of arterial oxygen (PaO2) from the
invasive arterial sample to calculate the PaO2/FiO2 according to Berlin criteria which may be difficult to apply in
limited resource settings and lead to underestimation of the patients with ARDS. The SpO2/FiO2 ratio has been
recently used as a measure for oxygenation status. We proposed a correlation between the non-invasive SPO2/FiO2
(S/F) ratio and the invasive PaO2/FiO2 (P/F) ratio in both non-invasive and invasive ventilation and the SpO2/FiO2
can be used instead of PaO2/FiO2. All attempts globally to change the definition of ARDS according to berlin criteria
by suing the non-invasive SpO2/FiO2 as well as the new trend of using ultrasound of the lung and the use of non
invasive high flow nasal canula. To study the correlation between the SpO2/FiO2 and the PaO2/FiO2 and determine
the cutoff values of SpO2/FiO2 that correlate with PaO2/FiO2 in patient with acute hypoxemic respiratory failure.
Patients with hypoxemia and acute respiratory failure and treated in the ICU by invasive and non-invasive measures
enrolled in this single center observational cross-sectional study which was conducted from August 2023 to March
2024 in the ICU department of Ghazi Alhariri hospital. Fractional inspired oxygen (FiO2), partial pressure of arterial
oxygen (PaO2) and oxygen saturation of hemoglobin (SpO2) were recorded from blood gas analysis reports and
monitoring of the patients simultaneously, the S/F and P/F ratios calculated, the correlation between the ratios were
noted by scatter plot with line of fit, The degree of correlation was determined using Spearman Pearson equation
and the cutoff values of S/F ratio determined by linear regression equation. A total of 100 sample data were collected.
The mean age of the patients in the study was57.38 year, the PaO2 mean was 100.81, the SpO2 mean was 96.32%,
the mean of calculated P/F ratio was 258.77 while the mean of calculated SpO2/FiO2 ratio was 244.75.