Heat and moisture exchanger

Heat and moisture exchangers (HME) are devices used in mechanically ventilated patients intended to help prevent complications due to "drying of the respiratory mucosa, such as mucus plugging and endotracheal tube (ETT) occlusion.

According to Branson (2007), the optimal humidification level "has been not well defined, but it is clear that in a patient with thick and copious secretions a heated humidifier is preferred to an HME".

[4] An HME has three purposes for patients with tracheostomies or laryngectomies: In the lungs a temperature of 37 °C and 100% relative humidity (RH) is the ideal condition for the ciliary activity.

[citation needed] HME cassettes with an electrostatic filter are designed to enhance the protection against airborne microbes to help to reduce the transfer of viruses and bacteria.

[citation needed] The basic components of heat and moisture exchangers are foam, paper, or a substance which acts as a condensation and absorption surface.

As antimicrobial filters, an HME is not considered to be an efficient barrier for microorganisms due to a relatively poor bacterial filtration capacity.