Background: Acute Hypoxemic respiratory failure (AHRF) is the most common form of respiratory failure. It is characterized by life-threatening derangements in arterial blood gases and acid-base status. The oxygen saturation index (OS I = MAP x Fi02/Sp02) which is a non-invasive measure, can be considered a robust index in defining acute lung disease because mean airway pressure is used, it provides a better pathophysiologic assessment of impaired lung function. The aim of this study is to determine the role of oxygen saturation index as a non-invasive measure in predicting patients with hypoxic respiratory failure.
Methods: This is a Cross-sectional, analytic study among all newly and on long term intubated patients aged 19 years old & above. Arterial Pa02, the oxygen saturation value; utilizing Onyx II 9550 finger Pulse Oximeter, and Paw from mechanical ventilator were recorded simultaneously. Ventilator settings at the time the specimen for blood gas drawn were recorded. Finally OSI was computed by the following equation: [(Paw; in cm H20 x Fi02)/ Sp02], and was compared with Pa02 levels of hypoxic respiratory failure. The sensitivity, specificity, positive and negative predictive value with a confidence interval of 95% of the oxygen saturation index in detecting AHRF was computed.
Results: A total of 109 patients were included in the study. A moderate statistically significant negative correlation between Pa02 and OSI was observed with a Pearson's r of -0.5090 and a p value of
Conclusion: This study has shown that calculated OSI score of 13 can be used as an adjunct non invasive diagnostic measure in predicting the AHRF in intubated patients with satisfactory but not optimal, sensitivity and specificity.