Study about Quality of Medical Breathable Compressed Air in Hospitals. Medical Gas Pipeline Systems a Microbiological Approach

Medical breathable compressed air is a pharmaceutical product, according to European Pharmacopoeia, that must be dry and free of contaminants. It is administrated through ventilators for mechanical ventilation, incubators, anesthesia ventilators and it is necessary in critical hospital departments, like ICU (Intensive Care Units), ER (emergency Rooms), OR (Operating Rooms), etc. The quality of the compressed air is determined by the level of humidity and the impurities it contains, like oil, other gases, water vapors. Contaminants (impurities) enter the compressed air system from three sources: atmospheric air, the air compressor, distribution pipes. The removal of these contaminants is achieved by passing the compressed air delivered by the compressor station through a drying and filtering equipment. The requirements regarding the purity of medical compressed air are indicated in the ISO 7396-1 and 7396-2 standards and in the European Pharmacopoeia. The presence of water in the medical air installation is a favorable environment for the development of bacteria. The amount of water vapor that remains in suspension without forming a liquid is determined by the air pressure and temperature. As the pressure increases, the volume of the gas mass decreases and thus the ability to hold water vapor decreases. There will always be water in the compressed air system, regardless of the type of compressors used. The problem is to remove this amount of water and keep the air pipes dry. The study compares the microbiological results obtained from two clinical hospitals. We tested the medical breathable compressed air in two points of the installation-at some point, after the bacteriological filters of medical air plant, and at the terminal unit.