A heat and moisture exchanger is required when a patient can no longer inspire and expire through the nose and mouth. The nose and mouth provide natural warmth, moisture, and filtration for the air we breathe. Having a tracheostomy tube, however, by-passes these mechanisms so humidification must be provided to keep secretions thin and avoid mucus plugs. In order to keep the environment at an optimal humidity level, Heat Moisture Exchangers are used.
