title: Breathing filters for use in inhalation anaesthesia and long-term respirator therapy. An analysis using pall breathing filters as an example.
abstract: The breathing filters tested in this investigation showed a high filtration effect. Therefore these filters can be assumed to protect the patient's airways very effectively from exogenous microbial loads, thus reducing the risk of extrinsic colonisation and infection. Of course intrinsic causes of infection, which prevail in long-term ventilation of patients, will respond neither to the use of breathing filters nor to disinfection of the ventilation equipment. Breathing filters protect both the patient's environment and the ventilation equipment from microbes exhaled by the patient. Hydrophobic filters with large inner surfaces such as those tested also act as heat and moisture exchangers; thus they reduce the need for air-humidification and eliminate a notorious source of respiratory-tract infection. Gain in dead space, blockage by condensed humidity and a tendency for thicker secretions are possible drawbacks which must be kept in mind when using breathing filters. The tested filters may be disposed of safely; neither dipping nor heat-sterilization or incineration will create hazard for the environment. The use of these filters may reduce significantly the frequency of respirator cleaning and disinfection as well as the costs incurred for staff, equipment repair and renewal. On the other hand, purchase, storage and disposal of the filters create running costs.
authors.affiliation: Hygiene Institut, Universität Wien.
authors.forename: W
authors.initials: W
authors.lastname: Koller
mesh_terms: D000391:Air Microbiology; D000769:Anesthesia, Inhalation; D005374:Filtration; D006801:Humans; D006813:Humidity; D012141:Respiratory Tract Infections / Q000517:prevention & control*; D012122:Ventilators, Mechanical