Correlation of Oxygen Saturation Index and Oxygenation Index in Hypoxaemic Respiratory Failure among Neonates

Abstract

Introduction: Hypoxaemic Respiratory Failure (HRF) is severe arterial hypoxaemia that is refractory to supplemental oxygen. Oxygen Saturation Index (OSI) can be an alternate method of diagnosing and assessing the severity of HRF as it uses Oxygen Saturation (SpO2) in place of Partial Pressure of Oxygen (PaO2) and may be utilised with reasonable sensitivity and specificity. Aim: To evaluate the correlation between OSI and Oxygenation Index (OI) in HRF in neonates. Materials and Methods: The prospective observational study was conducted in Kempegowda Institute of Medical Sciences and Hospital, Bengaluru, Karnataka, India, from December 2016 to July 2018. Fifty neonates who were admitted to Neonatal Intensive Care Unit (NICU) and conventionally ventilated in view of HRF were included. Arterial blood gases in the first 24 hours of life and corresponding oxygen saturations and ventilator settings were recorded. OI and OSI was calculated using the standard formula and their correlation was analysed. Results: The neonates were all on first day of life at admission to NICU and were invasively ventilated due to HRF. The mean birth weight was 1.89±0.84 kg. Of the 50 neonates, 22 (44%) were preterm babies (<34 weeks), 17 (34%) belonged to late preterm group (34 weeks to 36 weeks +6 days), 9 (18%) were term babies (>37 weeks), two neonates were extremely preterm (less than 28 weeks). In this study, OSI and OI significantly associated and correlated (p-value <0.01) with a correlation coefficient r=0.727. Area under the Receiver Operating Characteristic (ROC) curve for OSI was 0.912 which indicates that OSI is an excellent test to assess the severity of HRF. Conclusion: That OSI can be used to diagnose and assess the severity of lung disease in neonates having HRF.

Assessing hypoxic respiratory failure in mechanically ventilated neonates: A comparative study of oxygen saturation index and oxygenation index

“…These results are consistent with a prospective study of Sunil and Nithya (2021) conducted in similar settings that recruited both preterm and term in study group and each selected newborns only one paired OI and OSI measurement was evaluated. Sunil and Nithya conducted a study involving 50 neonates, both term and preterm, and reported a positive correlation between OSI and OI (p-value < 0.01) [ 9 ]. The correlation coefficient (r) was found to be 0.727, which aligns with the findings of our study.…”

“…In this study, the AUC was 0.912, indicating a good overall accuracy of the test. These findings suggest that OSI can be used with good accuracy as a substitute for OI in assessing the severity of respiratory failure in neonates [ 9 ]. Besides, Devleta et al (2018) also observed a correlation between mean values of OSI and OI in their study involving 101 ventilated neonates those similar mean of gestational age with participants our study, with a Pearson’s coefficient of 0.76 (p < 0.0001, 95% CI = 0.66–0.83) [ 10 ].…”