UMEM Educational Pearls

Category: Pediatrics

Title: Pediatric ARDS continued...

Keywords: ARDS, oxygenation index, OI, PALICC, acute lung injury, respiratory distress, PARDS (PubMed Search)

Posted: 10/27/2017 by Mimi Lu, MD
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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

  • Mild ARDS: 4 ≤ OI ≤ 8
  • Moderate ARDS: 8 ≤ OI < 16
  • Severe ARDS: OI ≥ 16
  • OI < 25: good outcome
  • OI 25-40: >40% mortality
  • OI > 40: Consider ECMO


1) Trachsel D, McCrindle BW, Nakagawa S, Bohn D. Oxygenation index predicts outcome in children wtih acute hypoxemic respiratory failure. Am J Respir Crit Care Med. 2005 Jul 15;172(2):206-11.
2) Pediatric Acute Respiratory Distress Syndrome: Consensus Recommendations from the Pediatric Acute Lung Injury Consensus Conference.  Pediatric Acute Lung Injury Consensus Conference Group. Pediatr Crit Care Med. 2015 Jun;16(5):428-39