High-Flow Oxygen Therapy in Pediatrics

Initial Flow Rate and Target Oxygen Saturation

• The goal is to match the child's peak inspiratory flow, which varies with respiratory rate and effort, with an initial flow rate calculated at 1-2 L/kg/min, for a typical 2-year-old weighing approximately 12 kg, this translates to an initial flow rate of 12-24 L/min 1, 2
• For children with normal lungs breathing room air, SpO2 ≥95% should be expected 3
• Avoid hyperoxia: once adequate oxygenation is achieved, titrate FiO2 to maintain SpO2 ≥94% while avoiding saturations of 100%, as this may correspond to PaO2 anywhere between 80-500 mmHg 1, 2

Clinical Monitoring and Titration

• Flow rates should be adjusted based on the child's size, respiratory rate, and respiratory effort 1, 2
• Humidification is mandatory for HFNC to prevent mucosal drying and thickening of pulmonary secretions 1, 2

Common Pitfalls to Avoid

• Avoid excessive flow rates that may cause discomfort, nasal trauma, or gastric distension 1, 2
• Do not assume normal SpO2 excludes serious pathology: pulse oximetry can be normal despite abnormal pH, elevated PaCO2, or severe anemia 5

When to Escalate Therapy

• If SpO2 remains <88-90% despite initial HFNC therapy at 2 L/kg/min, consider increasing FiO2 before increasing flow rate 5
• HFNC should not delay intubation when clinically indicated 6