How to Order High-Flow Oxygen for a 6-Year-Old
Start high-flow nasal cannula (HFNC) at 2 L/kg/min (approximately 40 L/min for a typical 6-year-old weighing 20 kg), set FiO2 to achieve SpO2 94-98%, and use heated humidification at 37°C. 1
Initial Flow Rate Settings
For pediatric patients above 10 kg, the minimum flow rate to qualify as true HFNC therapy is ≥10 L/min - anything below this threshold is considered conventional oxygen therapy, not high-flow. 1 However, this is merely the minimum threshold.
Recommended Starting Flow Rate
- Begin at 2 L/kg/min for optimal therapeutic effect 1, 2
- For a 6-year-old (typically 18-25 kg): start at 36-50 L/min 1
- Maximum flow rates can reach 60 L/min in children, though some patients cannot tolerate flows above 40-50 L/min despite theoretical benefit 1
The 2 L/kg/min starting rate is superior to 1 L/kg/min because it consistently meets patients' peak inspiratory flow demands, improves respiratory mechanics, reduces airway resistance, and decreases breathing effort more effectively. 2
FiO2 Titration
- Target SpO2: 94-98% for patients without risk of hypercapnia 1
- Start with FiO2 sufficient to achieve target saturation, then titrate in 5-10% increments 1
- Continuously monitor with pulse oximetry 1
Temperature Settings
- Set heated humidification to 34-37°C based on patient preference 1
- Higher temperatures (37°C) provide optimal humidification and prevent airway dryness 1
Monitoring Parameters
Monitor these parameters to assess treatment effectiveness:
- Respiratory rate should decrease with effective HFNC therapy 1
- Work of breathing - assess for reduced accessory muscle use 1
- Patient comfort - should improve with appropriate settings 1
- Oxygen saturation - continuous pulse oximetry 1
Flow Rate Adjustments
Increase flow by 5-10 L/min if:
- Increased work of breathing persists 1
- Respiratory distress continues 1
- Patient appears to be "outrunning" the flow (inspiratory flow exceeds delivered flow) 2
Decrease flow by 5-10 L/min if:
Critical Clinical Considerations
HFNC provides multiple therapeutic mechanisms beyond oxygen delivery:
- Creates positive end-expiratory pressure (PEEP effect) 3
- Flushes dead space in upper airways 3
- Reduces work of breathing 3
- Improves mucociliary clearance through humidification 3
Common pitfall to avoid: Starting at 1 L/kg/min is insufficient for most patients with moderate-to-severe respiratory distress, as this flow rate often fails to meet peak inspiratory flow demands and provides suboptimal improvement in respiratory mechanics. 2
When to Escalate Therapy
Prepare for intubation if the patient exhibits:
- Deteriorating respiratory effort despite HFNC 4
- Persistent hypoxia (SpO2 <92% on high FiO2) 4
- Exhaustion or altered mental status 4
- Rising PaCO2 with respiratory acidosis 4
Remember: Patients on HFNC are critically ill and require continuous monitoring with immediate access to escalation of care, including intubation capability. 3