Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Compressed Air”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed1987

Particle-size distribution of bitolterol mesylate solution delivered by four compressed-air nebulizer devices.

The particle-size distribution of bitolterol mesylate solution delivered by four types of compressed-air nebulizers was determined. Before nebulization, bitolterol mesylate solution 0.2% w/v was diluted to 0.0833% w/v with 0.9% sodium chloride solution. The following commercially available nebulizers were tested: DeVilbiss Nebulizer Model 645, Hudson 1720 (Updraft) Hand Held Nebulizer, Bard Inspiron 002220 Mini-Neb Nebulizer, and Bunn Mini Mist Set model 0140-041. The particle-size distribution of nebulized solutions was determined with a cascade impactor contained in an in vitro apparatus designed to simulate use by a patient. Assays of bitolterol mesylate in the cascade impactor apparatus were done by high-performance liquid chromatography. Only slight differences were found in the particle-size distributions among the four types of nebulizers; the calculated average particle size ranged from 3.0 to 3.6 micron. All nebulizers tested showed satisfactory, comparable particle-size distributions and performance with bitolterol mesylate solution.

Aerosols↗
PubMed1984

Two unusual cases of severe dysbarism after compressed air work in Hong Kong.

Two cases of unusual severe dysbarism are reported. One case occurred after working in compressed air at a pressure of 2.05 kg/cm2 (29 psi) for a duration of 27 min; the second case, after working for a duration of 6 h at a pressure of only 1.0 kg/cm2 (14.2 psi). The first case presented a combination of symptoms resembling "the chokes" and "the staggers," progressing into shock probably due to micro-air embolism. The second suffered chest pain and "the chokes," complicated by an underlying chest infection. Both were treated successfully by recompression.

Adult↗
PubMedDate not supplied

The effect of compressed air foam on the detection of hydrocarbon fuels in fire debris samples.

In 1998/99 the New Zealand Fire Service implemented compressed air foam delivery systems for the suppression of fires in rural areas. This study investigated whether the introduction of the foam to the seat of the fire created any problems in subsequent analyses of fire debris samples. No significant interferences from the foam were found when the samples were analysed by direct headspace using activated carbon strips. The only foam component detected was limonene.

Air↗
PubMed1999

Modeling breathing-zone concentrations of airborne contaminants generated during compressed air spray painting.

This paper presents a mathematical model to predict breathing-zone concentrations of airborne contaminants generated during compressed air spray painting in cross-flow ventilated booths. The model focuses on characterizing the generation and transport of overspray mist. It extends previous work on conventional spray guns to include exposures generated by HVLP guns. Dimensional analysis and scale model wind-tunnel studies are employed using non-volatile oils, instead of paint, to produce empirical equations for estimating exposure to total mass. Results indicate that a dimensionless breathing zone concentration is a nonlinear function of the ratio of momentum flux of air from the spray gun to the momentum flux of air passing through the projected area of the worker's body. The orientation of the spraying operation within the booth is also very significant. The exposure model requires an estimate of the contaminant generation rate, which is approximated by a simple impactor model. The results represent an initial step in the construction of more realistic models capable of predicting exposure as a mathematical function of the governing parameters.

Air Movements↗
PubMed1994

Compressed air injury of the colon complicated by rhabdomyolysis: case report.

We present a case of traumatic injury of the colon by compressed air. Elevated levels of urinary myoglobin, creatinine phosphokinase, lactate dehydrogenase, and glutamic oxaloacetic transaminase indicating rhabdomyolysis were noted. In this type of injury, rhabdomyolysis related to acute peripheral circulatory failure may occur because of obstruction of venous return to the heart following a great increase in intraperitoneal pressure.

Adult↗
PubMedDate not supplied

MR findings in the brains of compressed-air tunnel workers: relationship to psychometric results.

Cranial MR imaging was performed in 30 subjects who had been involved in compressed-air tunnel projects in and around Milwaukee, WI. Nineteen of these subjects had been exposed to various degrees of hyperbaric air as calculated by an exposure index (average PSI pressure gauge multiplied by the number of years exposed), while 11 of the subjects were age-matched controls who belonged to the same labor union but had not been exposed to hyperbaric air. All MR scanning was done on a 1.5-T unit, and axial, sagittal, and coronal T1, proton density, and T2-weighted images were obtained. Ventricular size was measured objectively. Foci of increased T2 intensity within deep white matter tracts were evaluated as to number and location, and psychometric testing was performed on both groups to exclude preexisting organic brain disease. The 19 subjects in the experimental group had a statistically higher number (p = .05) of white matter lesions (more than 152) than the control group (22 lesions), and 37% of the experimental group had more than 20 white matter lesions each (seven of 19 subjects) while only 18% of the control group had 10 or 11 lesions each. The experimental group had a five times higher risk than the control group of having high-grade lesions, and a high statistical correlation (p = .02) was found between the number and severity of lesions in the experimental group as compared with the control group when linear trend analysis was performed. No correlation was found between exposure index, MR grade or number, or aseptic necrosis. Ventricular size was normal in all subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2001

Cervico-thoracic disc protrusions in controlled compressed-air diving: clinical and MRI findings.

Prevalence of cervical and thoracic disc protrusions was investigated by MRI in 24 military long-term compressed-air divers and 24 controls. A total of 26 disc protrusions (17 cervical disc protrusions) were detected in 58% of the divers whereas 18 protrusions were detected in 38 % of the controls (13 disc cervical protrusions). There was no significant difference between groups and no correlation with the diving experience. Neurological examination revealed no clinical abnormalities. In contrast to a recent study, our results suggest that long-term divers are at no increased risk for accumulating spinal disc protrusions or intramedullary abnormalities.

Adult↗
PubMed1977

Aseptic necrosis of bone in a compressed air worker.

This paper reports a detailed examination of three lesions of aseptic necrosis of bone occurring in a man who had worked in compressed air eleven years previously. Although two of the lesions were juxta-articular, in neither had the bone collapsed. Histology of only one similar lesion is reported in the literature (McCallum et al. 1966). Necropsy material is considered, together with radiographs and bone scans of the same lesions taken four years earlier. Similar changes have been shown to occur in commercial divers. On the evidence of this case it becomes clear that radiography is limited in its use and that bone scans as an indicator of repair may be open to misinterpretation. There may be a place for operation before the onset of symptoms in these cases of aseptic bone necrosis.

Air↗
PubMed1989

Evaluation of ejectors using the venturi effect for a continuous positive airway pressure system without compressed air.

The purpose of this study is to perform a test in the application of the existing ejectors with the continuous positive airway pressure (CPAP) system without compressed air. Four types of ejector (jet mixer, the former and new puritan nebulizer and the deluxe nebulizer) for blending oxygen and room air by the Venturi effect were tested. A decrease of mixed gas flow and an increase of oxygen concentration were observed according to the increase of positive pressure in all systems. The former puritan nebulizer and deluxe nebulizer were found to be unavailable for the CPAP system for high oxygen concentration and low mixed gas flow for the increase of positive pressure. In the system, however, with the new puritan nebulizer and jet mixer, a sufficient mixed gas flow and an appropriate oxygen concentration could be supplied at an adequate positive pressure. The CPAP system using only oxygen was judged as possibly giving availability.

Journal Article↗
PubMed1992

Scuba tanks as a compressed air source in positive-pressure ventilation.

Throughout the developing world there is a general problem of ensuring regular deliveries of medical supplies to hospitals. This includes the supply of compressed gases. At one regional hospital in Vanuatu, we were faced with the problem of how to provide economically a source of compressed gas at regulated pressure to drive an anaesthetic ventilator. We eventually adapted the output from a Scuba cylinder for this purpose. This paper describes the simple modifications necessary and suggests other uses for this source of compressed air that could be implemented in hospitals with small to medium case loads and access to a diving compressor.

Diving↗
PubMed1984

Transcardial perfusion fixation of the CNS by means of a compressed-air-driven device.

In the present report we describe the construction of a systemic vascular perfusion device designed to perfuse small mammals with fixatives under a constant, controlled hydrostatic pressure. The device is powered by compressed-air. The construction of the device allows the interchange of vessels containing various perfusates during the perfusion, without having to interrupt the flow or alter the hydrostatic pressure. Large volumes of fixatives can be perfused in a relatively short time, leading to good preservation of brain tissue, both for light and electron microscopical purposes.

Animals↗
PubMed2006

Relevance of postmortem radiology to the diagnosis of fatal cerebral gas embolism from compressed air diving.

AIMS: To test the hypothesis that artefact caused by postmortem off-gassing is at least partly responsible for the presence of gas within the vascular system and tissues of the cadaver following death associated with compressed air diving. METHODS: Controlled experiment sacrificing sheep after a period of simulated diving in a hyperbaric chamber and carrying out sequential postmortem computed tomography (CT) on the cadavers. RESULTS: All the subject sheep developed significant quantities of gas in the vascular system within 24 hours, as demonstrated by CT and necropsy, while the control animals did not. CONCLUSIONS: The presence of gas in the vascular system of human cadavers following diving associated fatalities is to be expected, and is not necessarily connected with gas embolism following pulmonary barotrauma, as has previously been claimed.

Animals↗
PubMed1983

[Contamination of an oxygen delivery circuit by compressed air].

Routine checking of the FIO2 of a mixture delivered by a ventilator revealed large discrepancies between the FIO2 assigned and that effectively delivered, the latter being low. Measurements of FIO2 at the wall outlets showed the O2 delivery pipeline to be contaminated by compressed air. By disconnecting all the ventilators supplied by this pipeline one after the other, one ventilator, or rather its blender, was found responsible.

Air↗