Feasibility of synchronized high flow nasal cannula

Area of Science:

• Respiratory Physiology
• Mechanical Ventilation
• Critical Care Medicine

Background:

• Continuous high-flow nasal cannula (cHFNC) delivers constant airflow.
• Synchronized HFNC (sHFNC) utilizes diaphragm electrical activity (Edi) to cycle flow.
• Investigating sHFNC as an alternative to cHFNC is warranted.

Purpose of the Study:

• To demonstrate the feasibility of sHFNC.
• To compare sHFNC with cHFNC in an animal model.
• To assess sHFNC in an infant.

Main Methods:

• Eight rabbits were studied pre- and post-acute lung injury (ALI).
• Measurements included Edi, tracheal pressure, esophageal pressure, flow, and arterial CO2.
• One infant received sHFNC and cHFNC via Servo-U ventilator.

Main Results:

• sHFNC led to greater decreases in Edi, reduced esophageal pressure swings, and lower PaCO2 compared to cHFNC.
• sHFNC reduced dynamic hyperinflation indicated by lower baseline tracheal pressure.
• The ventilator successfully delivered Edi-synchronized flow in the infant.

Conclusions:

• Synchronized HFNC is feasible in infants.
• sHFNC decreases diaphragm effort and arterial CO2 in an animal model.
• sHFNC shows promise as an alternative respiratory support method.