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

Introduction: Continuously assessing the oxygenation levels of patients to detect and prevent hypoxemia can be advantageous for safe anesthesia, especially in neonates and small infants. The oxygen reserve index (ORI) is a new parameter that can assess oxygenation through a relationship with arterial oxygen partial pressure (PaO ). The aim of this study was to examine whether the ORI provides a clinically relevant warning time for an impending SpO (pulse oximetry hemoglobin saturation) reduction in neonates and small infants.