Early warning for SpO₂ decrease by the oxygen reserve index in neonates and small infants

Area of Science:

• Anesthesiology
• Pediatric Critical Care
• Biomedical Engineering

Background:

• Continuous monitoring of patient oxygenation is crucial for safe anesthesia, particularly in neonates and infants.
• The Oxygen Reserve Index (ORI) is a novel parameter designed to assess oxygenation by relating to arterial oxygen partial pressure (PaO2).
• Early detection of hypoxemia is vital to prevent adverse events during pediatric anesthesia.

Purpose of the Study:

• To evaluate the clinical relevance and warning time provided by the ORI for impending SpO2 (pulse oximetry hemoglobin saturation) reductions in neonates and small infants.
• To assess the sensitivity of ORI alarms in detecting decreases in SpO2 during general anesthesia in infants.
• To determine the agreement between ORI and PaO2 measurements with blood gas analyses in this pediatric cohort.

Main Methods:

• Continuous measurement of ORI and SpO2 in infants under 2 years old during general anesthesia.
• Calculation of warning time and sensitivity for different ORI alarm settings to detect SpO2 decrease.
• Assessment of ORI and PaO2 agreement with blood gas analysis results.

Main Results:

• The ORI provided a median warning time of 84 seconds for SpO2 decrease during anesthesia, with a sensitivity of 55%.
• During anesthesia induction, the warning time was 63 seconds with 56% sensitivity.
• The agreement between ORI and PaO2 intervals was poor (kappa = 0.00), and infant weight and height correlated with correct PaO2 classification by ORI.

Conclusions:

• While the ORI offered an early warning for SpO2 decrease in neonates and small infants, its sensitivity and agreement with PaO2 were insufficient for clinical recommendation.
• The study suggests that the ORI, in its current form, may not be a reliable early warning indicator for detecting hypoxemia in this vulnerable age group.
• Further research may be needed to refine ORI algorithms or explore its utility in conjunction with other monitoring parameters for pediatric anesthesia.