General information
A low dead-space volume, heat and moisture exchange filter: used with anaesthesia breathing circuits.
The filter minimizes the risk of cross transmission of bacteria and/or viruses between patients who are using the same anaesthetic breathing system.
Single-use, this product must be replaced at least once every 24 hours.
Should be positioned as close as possible to the patient to protect the rest of the breathing system.
Specification
The Heat and Moisture Exchanger (HME) filter offers viral and bacterial protection. It is a medical device designed to protect a patient’s respiratory tract from dryness and to minimize the risk of cross infections.
Components:
Rigid filter housing with two standard connection ports: 22M and 15F. A filter sampling port to measure concentrations of gases or agents must be located on the anaesthetic breathing side of the system.
Materials:
Two types of filter:
Hygroscopic filter: a felt-like electrostatic material made of paper that has been coated with calcium chloride, glass fibre or lithium-chloride-coated polypropylene
Hydrophobic filters: folded ceramic fibre elements.
Specifications:
Two types of filters are available on the market.
Electrostatic or hygroscopic filter (e.g., Hygrobac S manufactured by Mallinckrodt Dar).
Relies on an electrical charge to attract oppositely-charged particles.
A hygroscopic layer is added to the filter in order to retain expiratory water vapours, which are reused to humidify inhaled gases.
NOTE: Efficacy is reduced when wet. It also has a limited lifespan.