The Effects of Gas Humidification with High-Flow Nasal Cannula on Cultured Human Airway Epithelial Cells

Abstract EN

Humidification of inspired gas is important for patients receiving respiratory support.

High-flow nasal cannula (HFNC) effectively provides temperature and humidity-controlled gas to the airway.

We hypothesized that various levels of gas humidification would have differential effects on airway epithelial monolayers.

Calu-3 monolayers were placed in environmental chambers at 37°C with relative humidity (RH) < 20% (dry), 69% (noninterventional comparator), and >90% (HFNC) for 4 and 8 hours with 10 L/min of room air.

At 4 and 8 hours, cell viability and transepithelial resistance measurements were performed, apical surface fluid was collected and assayed for indices of cell inflammation and function, and cells were harvested for histology (n=6/condition).

Transepithelial resistance and cell viability decreased over time (P<0.001) between HFNC and dry groups (P<0.001).

Total protein secretion increased at 8 hours in the dry group (P<0.001).

Secretion of interleukin (IL)-6 and IL-8 in the dry group was greater than the other groups at 8 hours (P<0.001).

Histological analysis showed increasing injury over time for the dry group.

These data demonstrate that exposure to low humidity results in reduced epithelial cell function and increased inflammation.