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At least 19 recordsLinked to original sources
PubMed1998

Elimination of microorganisms from dental operatory compressed air.

Compressed air is used to power high-speed handpieces, as well as to dry and clean surfaces in the oral cavity during patient treatment, in all dental operatories. The compressed air used in the dental operatories located in large institutions such as universities or hospitals is generally obtained from a central source, and is produced by continually running compressors. In operatories located in private practice settings, compressed air is obtained from small on-site air compressors, which may be run less frequently. A survey was made of operatories in the Montreal area to determine the microbial load of the compressed air produced by air compressors. An air sampler was used to collect compressed air and impinge it on a rotating agar medium surface. Compared to the air produced from compressors in constant use, the air collected from compressors that ran intermittently had a very high microbial load. The efficacy of an apparatus designed to sterilize the contaminated air produced by small, on-site compressors was tested. Called a Purilair, this device heats every particle of inflowing compressed air to 250 degrees C and then forces it through a fine-pore ceramic filter. In three private practice operatories, an in-line Purilair effectively sterilized the air being delivered by small compressors. The same result was obtained in the laboratory when lyophilized spores and cells of Bacillus stearothermophilus and conidia of Penicillium notatum and Aspergillus niger were sprayed into the intake line of the apparatus.

Academic Medical Centers↗
PubMedDate not supplied

[Perforation of the large intestine caused by compressed air. Experimental studies reconstructing compressed air insufflation].

A foreign worker died after a compressed air injury. The insufflation of high pressure air into the anus caused multiple ruptures in the part anterior of the dilated sigmoid and colon descending. For the reconstruction of the case it was necessary to know the minimum distance between the nozzle and the gluteal region. Experimental work has shown that clothing does offer protection against the high pressure air and colon perforations can only be expected if there is a small distance between the jet of the compressed air and the anal region.

Air Pressure↗
PubMed1989

Changes in lung function after working with the shotcrete lining method under compressed air conditions.

Shotcrete techniques under compressed air are increasingly applied in the construction of tunnels. Up to now little is known about the influence of shotcrete dusts on the function of the lung. The lung function of 30 miners working with shotcrete under compressed air (before and after one shift) was measured. They carried personal air samplers to assess the total dust exposure. Long term effects were studied on a second group of 29 individuals exposed to shotcrete dusts and compressed air for two years. A significant increase of airway resistance and a significant decrease of some flow-volume parameters were found after one workshift. These changes partially correlate close to the dust exposure. After two years exposure a significant decrease of mean expiratory flow (MEF)50 and MEF25 was found. These results point to damage in the small airways and emphasise the major role of the lung function test--including the flow-volume manoeuvre for the medical examination of the workers. Additionally, they should carry filter masks.

Adult↗
PubMedDate not supplied

An IMV setup without a compressed air source.

Intermittent mandatory ventilation (IMV), as described in the literature, utilizes an air-oxygen blender and a compressed air source. When older ventilators are used and in locations in which compressed air sources are unavailable, other arrangements must be made if IMV is to be used. An arrangement is described in which a bird Mark 7 respirator, after the removal of its pneumatic clutch, is inserted into the IMV assembly. Such an arrangement produces wide FIO2 ranges and high flows and obviates the need for an oxygen blender and compressed air source. If a compressed air source is available or if a bird Mark 7 respirator is not available for use, othe arrangements may be more satisfactory.

Intermittent Positive-Pressure Breathing↗
PubMed1999

Unintended inhalation of nitric oxide by contamination of compressed air: physiologic effects and interference with intended nitric oxide inhalation in acute lung injury.

BACKGROUND: Compressed air from a hospital's central gas supply may contain nitric oxide as a result of air pollution. Inhaled nitric oxide may increase arterial oxygen tension and decrease pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. Therefore, the authors wanted to determine whether unintentional nitric oxide inhalation by contamination of compressed air influences arterial oxygen tension and pulmonary vascular resistance and interferes with the therapeutic use of nitric oxide. METHODS: Nitric oxide concentrations in the compressed air of a university hospital were measured continuously by chemiluminescence during two periods (4 and 2 weeks). The effects of unintended nitric oxide inhalation on arterial oxygen tension (n = 15) and on pulmonary vascular resistance (n = 9) were measured in patients with acute lung injury and acute respiratory distress syndrome by changing the source of compressed air of the ventilator from the hospital's central gas supply to a nitric oxide-free gas tank containing compressed air. In five of these patients, the effects of an additional inhalation of 5 ppm nitric oxide were evaluated. RESULTS: During working days, compressed air of the hospital's central gas supply contained clinically effective nitric oxide concentrations (> 80 parts per billion) during 40% of the time. Change to gas tank-supplied nitric oxide-free compressed air decreased the arterial oxygen tension by 10% and increased pulmonary vascular resistance by 13%. The addition of 5 ppm nitric oxide had a minimal effect on arterial oxygen tension and pulmonary vascular resistance when added to hospital-supplied compressed air but improved both when added to tank-supplied compressed air. CONCLUSIONS: Unintended inhalation of nitric oxide increases arterial oxygen tension and decreases pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. The unintended nitric oxide inhalation interferes with the therapeutic use of nitric oxide.

Administration, Inhalation↗
PubMed2001

Microbiological contamination of compressed air used in dentistry: an investigation.

The purpose of this preliminary investigation was twofold: 1) to examine the possibility of cross-contamination between a dental-evacuation system and the compressed air used in dental operatories and 2) to capture and identify the most common microflora in the compressed-air supply. The investigation used swab, water, and air sampling that was designed to track microorganisms from the evacuation system, through the air of the mechanical room, into the compressed-air system, and back to the patient. Samples taken in the vacuum system, the air space in the mechanical room, and the compressed-air storage tank had significantly higher total concentrations of bacteria than the outside air sampled. Samples of the compressed air returning to the operatory were found to match the outside air sample in total bacteria. It was concluded that the air dryer may have played a significant role in the elimination of microorganisms from the dental compressed-air supply.

Aerosols↗
PubMed1997

Compressed air tunneling and caisson work decompression procedures: development, problems, and solutions.

Multinational experience over many years indicates that all current air decompression schedules for caisson and compressed air tunnel workers are inadequate. All of them, including the Occupational Safety and Health Administration tables, produce dysbaric osteonecrosis. The problem is compounded because decompression sickness (DCS) tends to be underreported. Permanent damage in the form of central nervous system or brain damage may occur in compressed air tunnel workers, as seen on magnetic resonance imaging, in addition to dysbaric osteonecrosis. Oxygen decompression seems to be the only viable method for safely decompressing tunnel workers. Oxygen decompression of tunnel workers has been successfully used in Germany, France, and Brazil. In Germany, only oxygen decompression of compressed air workers is permitted. In our experience, U.S. Navy tables 5 and 6 usually prove adequate to treat DCS in caisson workers despite extremely long exposure times, allowing patients to return to work following treatment for DCS. Tables based on empirical data and not on mathematical formulas seem to be reasonably safe. U.S. Navy Exceptional Exposure Air Decompression tables are compared with caisson tables from the United States and Great Britain.

Decompression↗
PubMedDate not supplied

Compressed-air power tools in orthopaedic surgery: exhaust air is a potential source of contamination.

OBJECTIVES: To determine if the exhaust from surgical compressed-air power tools contains bacteria and if the exhaust leads to contamination of sterile surfaces. DESIGN: Bacteriologic study of orthopaedic power tools. SETTING: Level I trauma center operative theater. PATIENTS/PARTICIPANTS: None. INTERVENTION: Part I. Exhaust from two sterile compact air drills was sampled directly at the exhaust port. Part II. Exhaust from the drills was directed at sterile agar plates from varying distances. The agar plates represented sterile surfaces within the operative field. Part III. Control cultures. A battery-powered drill was operated over open agar plates in similar fashion as the compressed-air drills. Agar plates left open in the operative theater served as controls to rule out atmospheric contamination. Random cultures were taken from agar plates, gloves, drills, and hoses. MAIN OUTCOME MEASUREMENT: Incidence of positive cultures. RESULTS: In Part I, all filters from both compressed-air drill exhausts were culture negative ( = 0.008). In Part II, the incidence of positive cultures for air drills number one and number two was 73% and 82%, respectively. The most commonly encountered organisms were, coagulase-negative Staphylococcus, and Micrococcus species. All control cultures from agar plates, battery-powered drill, gloves, and hoses were negative ( < 0.01). CONCLUSIONS: Exhaust from compressed-air power tools in orthopaedic surgery may contribute to the dissemination of bacteria onto the surgical field. We do not recommend the use of compressed-air power tools that do not have a contained exhaust.

Air Microbiology↗
PubMed1997

Low levels of nitric oxide as contaminant in hospital compressed air: physiologic significance?

OBJECTIVES: To determine whether the levels of nitric oxide found in hospital compressed air have a clinically relevant effect on oxygenation in intubated patients with normal lungs. DESIGN: Prospective study. SETTING: Cardiothoracic and surgical intensive care unit in a university hospital. PATIENTS: Twelve postoperative patients receiving mechanical ventilation. INTERVENTIONS: Pure nitrogen and oxygen were substituted for hospital compressed air as a source of blending for correct FIO2. MEASUREMENTS AND MAIN RESULTS: Hemodynamics and PaO2 were measured in nitrogen and oxygen used for blending oxygen during stable FIO2 levels. Inhaled nitric oxide was measured with a nitric oxide-chemiluminescence detector. There was no clinically relevant change in systemic hemodynamics. However, the PaO2 decreased significantly when nitrogen was used for blending. Inhaled nitric oxide levels varied from 2 to 550 parts per billion during use of hospital compressed air; no nitric oxide was detectable during use of nitrogen. CONCLUSIONS: The low concentration of nitric oxide in hospital compressed air improves oxygenation in patients with normal lungs receiving mechanical ventilation.

Blood Gas Analysis↗
PubMed1996

[Health check on divers and compressed air workers].

We have conducted the health check of 3,554 compressed air workers and 1,821 divers, and also examined the incidence and severity of aseptic bone necrosis by using Roentgen pictures. We could classify 4,859 of 5,375 persons into four groups (A-D), based on our classification. We could also classify 4,205 of 5,375 persons that had had a bone X ray examination on the basis of the criteria described by Ota and Matsunaga (A-C). 4,859 persons belonged to four groups: class A (persons who can work, no limitations): 4,099 (84.4%), class B (persons who can work under conditions below 1.0 kg/cm2): 357 (7.3%), class C (persons who had better quit work under hyperbaric conditions, though they are not prohibited by regulations): 183 (3.8%), class D (persons who must be prohibited from working in a hyperbaric environment by laws of the Ministry of Labor): 88 (1.8%). About 90% of compressed air workers and divers (classes A and B) were permitted to work under hyperbaric conditions. Most of those belonging to classes C and D suffered from hypertension, cardiovascular disease and liver dysfunction. The incidence of aseptic bone necrosis was 11.1% (465 out of 4,205 persons). Eight persons (2.2%) belonged to criteria A which means poor prognosis. They were classified into class D. There is no differences between compressed air workers and divers in the incidence of aseptic bone necrosis.

Adult↗
PubMed1987

Possible role of vacuum systems and compressed air generators in cross-infection in the ICU. A radioactive tracer study.

Cross-contamination between a hospital's vacuum and compressed air systems was demonstrated using xenon-133 as a tracer. A xenon-133 bolus was introduced to the vacuum system in the intensive care unit. Calculations based on the amount of radioactive tracer recovered from the compressed air outlet at the same location as that at which the tracer was introduced indicated that 17% of the tracer had entered the compressed air system. The contamination was caused because the vacuum and compressed air systems were located in the same machine room. This could conceivably provide a route for respiratory tract contamination in patients receiving ventilatory assistance with air-oxygen mixtures.

Air↗
PubMed1981

[Effects of variations in the ascending speed on the production of circulating gas bubbles after compressed-air diving].

Ninety-seven compressed air divers at depths of 20 to 52 msw were done. Every dive reached a tissue nitrogen saturation level greater than or equal to M value according to U.S. Navy decompression schedules and respected all prescribed decompression stop. Dives were divided in two groups according to the speed of ascent:--1st group: 33 dives (18 simulated, 15 open water) with ascent at 18 msw/min. for the first half of the distance and 10 msw/min. for the second half. No work on the bottom. Average ascent rate 14 msw/min. This profile was due to the flow limits of the outlet of our chamber during the second part of the ascent, and it was repeated in open water diving.--2nd group: 64 dives (4 simulated, 60 open water) with linear ascent at 10 msw/min. Half the open water dives were repetitive within 4 hours from the first one. Medium to heavy work on the bottom. Ultrasound Doppler bubble detection at rest and after exercise was performed at five minutes intervals and during 40 minutes after surfacing.

Diving↗