The Relationship between High Flow Nasal Cannula Flow Rate and Effort of Breathing in Children

Area of Science:

• Pediatric Intensive Care
• Respiratory Support
• Neonatal Medicine

Background:

• High flow nasal cannula (HFNC) therapy is increasingly used in pediatric intensive care units.
• Optimizing HFNC flow rates is essential for effective respiratory support in young children.
• Objective metrics are needed to guide HFNC titration.

Purpose of the Study:

• To identify optimal high flow nasal cannula (HFNC) flow rates in children under 3 years of age.
• To utilize an objective measure of breathing effort to guide HFNC titration.
• To evaluate the impact of different HFNC flow rates on respiratory mechanics.

Main Methods:

• A prospective, single-center trial was conducted in a pediatric intensive care unit.
• The study involved 21 children under 3 years of age receiving HFNC therapy.
• The pressure-rate product (PRP), an objective measure of breathing effort, was analyzed at varying weight-indexed flow rates (0.5-2.0 L/kg/min).

Main Results:

• Increasing HFNC flow rates significantly reduced the percent change in PRP across the cohort (P < .001).
• The greatest reduction in breathing effort was observed at 2.0 L/kg/min (-21%).
• Children weighing ≤8 kg demonstrated a more pronounced reduction in breathing effort compared to those >8 kg (P = .001).

Conclusions:

• Optimal HFNC flow rates for reducing respiratory effort in young children are approximately 1.5-2.0 L/kg/min.
• These flow rates provide the most significant benefit in decreasing the work of breathing.
• Younger children and those weighing ≤8 kg appear to benefit most from higher HFNC flow rates.