Some pediatric practitioners have adopted the oxygenation index (OI) ([FiO2 × mean airway pressure (Paw) × 100]/ PaO2) or oxygen saturation index (OSI) ([FiO2 × Paw × 100]/ SpO2) to assess hypoxemia in children instead of P/F ratios because of the less standardized approach to positive pressure ventilation in children relative to adults.
OI can be used in pediatric patients to define severity of Acute Respiratory Distress Syndrome (ARDS) in patients receiving invasive mechanical ventilation and assess for potential ECMO treatment.
In contrast, the P/F ratio should be used to diagnose Pediatric ARDS for patients receiving noninvasive continuous positive airway pressure [CPAP] or bilevel positive airway pressure [BiPAP]) with a minimum CPAP of 5 cm H2O.
Oxygen Index (OI) = FiO2 x MAP x 100 --------------------- PaO2
