Efficiency of different flows for apneic oxygenation when using high flow nasal oxygen application - a technical...

Area of Science:

• Anesthesiology
• Respiratory Physiology

Background:

• Preoxygenation and apneic oxygenation are crucial for preventing desaturation during emergency intubation.
• High flow oxygen delivery can prolong the time to desaturation by maintaining oxygen levels in the airway.

Purpose of the Study:

• To scientifically assess the necessary flow rate of high flow nasal oxygen (HFNO) to prevent nitrogen entrainment in a manikin model during simulated apneic oxygenation.

Main Methods:

• A human manikin with a preoxygenated test lung was used to simulate apneic oxygenation over 20 minutes.
• Groups received either room air (control) or pure oxygen via HFNO at 10, 20, 40, 60, and 80 L/min.
• Oxygen content in the test lung was measured over the observation period.

Main Results:

• Oxygen content in the control group dropped significantly to 43% compared to baseline (97%).
• HFNO at 10 L/min maintained oxygen content at 92%, with minimal significant differences compared to 20 L/min (92%) and 40 L/min (90%).
• Higher HFNO flows (60 and 80 L/min) resulted in slightly decreased oxygen percentages (89% and 87%, respectively).

Conclusions:

• Simulated apneic oxygenation using HFNO at 10 L/min maintained the highest oxygen content in the test lung over 20 minutes.
• Flow rates higher than 10 L/min showed a trend towards slightly decreased oxygen percentages.
• The study suggests an optimal HFNO flow rate for maintaining oxygenation during apneic periods.