Comparison of SpO2/FiO2 ratio and PAO2/FIO2 ratio as initial assessment in patients at risk of respiratory failure

Comparison of SpO2/FiO2 ratio and PAO2/FIO2 ratio as initial assessment in patients at risk of respiratory failure

Authors

  • Mohammad Gilang Fajriansyah Nohu Hasanuddin University
  • Satriawan Abadi Hasanuddin University
  • Harun Iskandar Hasanuddin University
  • Syakib Bakri Hasanuddin University
  • Hasyim Kasim Hasanuddin University
  • Andi Alfian Zainuddin Hasanuddin University

Keywords:

Respiratory failure, SpO2/FiO2 ratio, PaO2/FiO2 ratio, shortness of breath

Abstract

Introduction: The risk of respiratory failure such as shortness of breath which causes difficulty in the breathing process, if not treated properly can result in respiratory failure, then organ failure with high morbidity and mortality. These risks can be identified by measuring oxygen saturation with oximetry. The purpose of this study is to determine and examine the comparison of the Oxygen saturation/Fraction of inspired oxygen (SpO2/FiO2) ratio and the Partial pressure of oxygen /Fraction of inspired oxygen (PaO2/FiO2) ratio as an initial assessment in patients at risk of respiratory failure. Methods: Cross-sectional study conducted among patients in the emergency room and treatment room at Wahidin Sudirohusodo Hospital Makassar and its network with symptoms of shortness of breath. The data collected from the results of blood gas analysis, oxygen saturation examinations, and patient medical records. Results: A total of 103 samples were obtained with an age range of 20-87 years. Based on the data, the mean SpO2 value was 95.7%, PaO2 was 163.3 mmHg, FiO2 was 70.7%, SpO2/FiO2 ratio was 175.1 mmHg and PaO2/FiO2 ratio was 332.2 mmHg. The threshold value of the SpO2/FiO2 ratio for respiratory failure of 281 corresponds to the PaO2/FiO2 ratio of 300 with a sensitivity of around 93% and a specificity of 96%. Conclusion: The SpO2/FiO2 ratio was strongly correlated with the PaO2/FiO2 ratio in assessing respiratory failure. So, the SpO2/FiO2 ratio can be used as an alternative to the PaO2/FiO2 ratio for early detection in patients at risk of respiratory failure. 

Author Biographies

Mohammad Gilang Fajriansyah Nohu, Hasanuddin University

Department of Internal Medicine, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia

Satriawan Abadi, Hasanuddin University

Department of Internal Medicine, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia

Harun Iskandar, Hasanuddin University

Department of Internal Medicine, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia

Syakib Bakri, Hasanuddin University

Department of Internal Medicine, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia

Hasyim Kasim, Hasanuddin University

Department of Internal Medicine, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia

Andi Alfian Zainuddin, Hasanuddin University

Department of Public Health and Community Medicine, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia

References

1. American Thoracic Society. Dyspnea: Mechanism, assessment, and management: a consensus statement. Am J Respir Crit Care Med. 1999; 159:321-40. doi: 10.1164/ajrccm.159.1. ats898

2. Mehta TR, Shah CT, Lakhani JD, Lakhani D. Can pulse oximetric saturation (SpO2)/fraction of inspired oxygen (FiO2) ratio surrogate PaO2/ FiO2 ratio in diagnosing acute respiratory failure? International Journal of Biomedical and Advance Research. 2016; 7(5): 242-246. doi: 10.7439/ijbar

3. Vincent JL, Akça S, Mendonça A, et al. The epidemiology of acute respiratory failure in critically ill patients. Chest. 2002; 121: 1602-9.doi: org/10.1378/chest.121.5.1602

4. Sue DY and Bongard FS. Respiratory Failure. In Current Critical Care Diagnosis and Treatment - 2nd edition. 2003. California. Lange-McGrawHill. 2003. Pp. 269-89. doi: 10.1186/cc2371

5. Pisani L, Roozeman JP, Simonis FD, et al. Risk stratification using SpO2/FiO2 and PEEP at initial ARDS diagnosis and after 24 h in patients with moderate or severe ARDS. Ann Intensive Care. 2017;7(1). doi: 10.1186/s13613-017-0327-9

6. Babu S, Abhilash KPP, Kandasamy S, Gowri M. Association between SpO2 / FiO2 Ratio and PaO2 / FiO2 Ratio in Different Modes of Oxygen Supplementation. Indian J Crit Care Med. 2021; 25(9):1001-1005. doi: 10.5005/jp-journals-10071-23977

7. Matthay MA, Arabi Y, Arroliga AC, et al. WORKSHOP A New Global Definition of Acute Respiratory Distress Syndrome. Am J Respir Crit Care Med. 2024;209(1):37-47. doi: org/10.1164/rccm.202303-0558WS

8. Festic E, Bansal V, Kor DJ, Gajic O. SpO2/FiO2 ratio on hospital admission is an indicator of early acute respiratory distress syndrome development among patients at risk. J Intensive Care Med. 2015;30(4):209-216. doi: org/10.1177/0885066613516411

Downloads

Published

23-06-2025

Issue

Section

ORIGINAL CLINICAL RESEARCH

How to Cite

1.
Nohu MGF, Satriawan Abadi, Harun Iskandar, Syakib Bakri, Hasyim Kasim, Andi Alfian Zainuddin. Comparison of SpO2/FiO2 ratio and PAO2/FIO2 ratio as initial assessment in patients at risk of respiratory failure. Acta Biomed. 2025;96(3):16567. doi:10.23750/abm.v96i3.16567