OVERVIEW
Heat and Moisture Exchanger (HME)
those in current use are generally combined with a microbiological filter, hence they are called HME filters (HMEF)
when passive humidification using an HME is use, the circuit is termed a “dry circuit” as a opposed to a “wet circuit” using active humidification
USES
humidification, warming inspired gases and microbiological filtration
best used in patients with few secretions, who are not hypothermic, do not have large air leaks and do not have high airway resistance
DESCRIPTION
Generally contains a layer of foam or paper embedded with a hydroscopic salt such as calcium chloride
Bacterial and viral filters ideally have filtration efficiency of >99.9%
HME with humidification efficiency >30mg.H2O/L
connects to a standard 15mm connector on an endotracheal tube