The combination of an electrostatic flter and HME media in an HMEF not only provides protection against cross-infection, but also
uses heat and humidity from the patient’s expired breath to warm and humidify anaesthetic gases during inspiration. When the upper
airway is bypassed, such as by intubation, cold and dry gases are delivered to the lungs, causing adverse physiological effects. Using an
HMEF to passively warm and humidify the gases helps counteract the risk of atelectasis, epithelial damage and reduction of mucocillary
transport