Role of Oxygen Saturation Index as a Noninvasive Surrogate Marker of Oxygenation in Intubated Critically Ill Adult Patients: A Prospective Observational Study
Year: 2025
Type: article
Study design: Observational Study
Abstract: Background and aim: This study aims to compare the oxygenation saturation index (OSI), a noninvasive marker, with commonly used invasive markers of oxygenation [PaO 2 , PaO 2 to FiO 2 (P/F) ratio, oxygenation index (OI)] in critically ill patients requiring invasive mechanical ventilatory support after 48 hours of admission in a surgical intensive care unit (ICU).Patients and methods: A total of 91 intubated patients aged between 18 and 75 years admitted to the surgical ICU with preexisting or new onset respiratory failure were recruited as per predefined exclusion and inclusion criteria after being on the ventilator for 48 hours.Patients were enrolled in the study for 7 days or till extubation, tracheostomy, or death.The OSI was compared with other invasive and noninvasive markers to assess correlation.Results: Strong correlation of OSI with P/F ratio, SpO 2 /FiO 2 (S/F) ratio, and OI individually was noted up to 7 days post 48 hours of intubation in critically ill patients, while it correlated with SpO 2 on days 2, 3, 4, and 5 and PaO 2 on days 2, 4, and 5, respectively.Correlation after natural logarithmic transformation was strongest for OI (r = 0.833), followed by S/F ratio (r = 0.686), P/F ratio (r = 0.409), SpO 2 (r = 0.229), and weakest for PaO 2 (r = 0.045).Conclusion: Oxygen saturation index is a valid noninvasive marker of oxygenation in critically ill intubated patients and correlates well with invasive markers of oxygenation.
Authors: Abraham Koshy, George Kurian, Shoma V Rao, Subramani K, Jubin Jacob, David Vincent, Grace Rebekah J
Institution: Christian Medical College, Vellore
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W4414376472