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At least 55 records · Page 3Linked to original sources
PubMed1982

Aseptic necrosis in compressed air tunnel workers using current OSHA decompression schedules.

Aseptic necrosis (dysbaric osteonecrosis) was discovered in two compressed air tunnel workers who had used the present Occupational Health and Safety Administration (OSHA) decompression tables for compressed air tunneling at pressures greater than 36 pounds per square inch gauge (psig). A roentgenographic study was made of 21 men who had worked at pressures up to 43 psig using the OSHA schedules. Bone scanning was also included. Seven of the men (33%) were found to have aseptic necrosis involving the shoulders, hips or distal femoral shafts and proximal tibia. It became evident that the present OSHA schedules caused not only an unacceptable incidence of decompression sickness but also aseptic necrosis at pressures over 36 psig. New interim tables that are more conservative and that use either air or oxygen as a breathing gas during decompression are undergoing laboratory and worksite evaluation.

Adult↗
PubMed1989

Compressed air injury to the esophagus: case report.

Compressed air injuries to the esophagus are uncommon. They characteristically present with respiratory distress, subcutaneous and mediastinal emphysema, and may have a pneumothorax. The distal esophagus is always the site of rupture and requires prompt surgical repair to avoid serious morbidity and potential lethal complications.

Air Pressure↗
PubMed1986

Bacterial contamination of compressed air for medical use.

The present study demonstrates a previously unnoticed source of bacterial contamination of locally manufactured compressed air for medical use. Air samples were drawn into a specially constructed device, and bacterial contents were identified from growth on agar plates. Various factors contributing to bacterial contamination of compressed air during production are mentioned and preventive measures are discussed.

Air Microbiology↗
PubMed1977

[Bone and joint changes due to compressed air in divers and Caisson workers (author's transl)].

The radiological and morphological changes of Caisson disease in the skeleton are well known. The findings of interest to radiologists are described. Because of its position, its was possible to review a large number of divers in Kiel; these have been under observation for years, and even decades. The development, manifestation and course of chronic skeletal changes due to compressed air are described to compressed air are described and, according to severity, are classified into types 1 to 4. Late changes are discussed in detail, since these are of importance in relation to compensation.

Bone Diseases↗
PubMed1990

Acute decompression sickness in compressed air workers exposed to pressures below 1 bar in the Singapore Mass Rapid Transit project.

The Singapore Mass Rapid Transit (MRT) project started compressed air work in Oct 1984. Eleven km of underground tunnels out of 20 km were built using this method. Cases of decompression sickness (DCS) arising from compressed air work are rare with working pressures less than 1 bar gauge. However, there were 10 cases of DCS in the MRT project who were exposed to less than 1 bar pressure. The authors present their clinical features and attempt to explain the observations in relation to theories of bubble nuclei formation, gas loading and rate of decompression. The formation of bubble micronuclei are correlated with physical factors like heavy exertion, and the use of vibrating tools. The concept of extremely long tissue half-times in the absorption of nitrogen in the body is discussed as a contributory factor to the development of DCS under 1 bar.

Acute Disease↗
PubMed1996

Colorectal injury by compressed air--a report of 2 cases.

We report two colorectal trauma patients whose rectosigmoid region was ruptured due to a jet of compressed air directed to their anus while they were playing practical jokes with their colleagues in their place of work. It was difficult to diagnose in one patient due to vague symptoms and signs and due to being stunned by a stroke of the compressed air. Both patients suffered from abdominal pain and distension, tension pneumoperitoneum and mild respiratory alkalosis. One patient was treated with primary two layer closure, and the other with primary two layer closure and sigmoid loop colostomy. Anorectal manometry and transanal ultrasonography checked 4 weeks after surgery, revealed normal anorectal function and anatomy. The postoperative courses were favorable without any wound infection or intraabdominal sepsis.

Accidents, Occupational↗
PubMed1980

Multiple perforations of colon after compressed air injury.

Multiple perforations of the colon after compressed air injury occurred. The initial perforation did not become manifest until five days after the injury. This was repaired at laparotomy and a proximal colostomy was performed. Ten days after the first operation, a second laparotomy showed a second larger tear at the level of the peritoneal reflection. After a Hartmann procedure, the patient did well and was discharged from the hospital. This case emphasizes the need for repeated exploratory surgery of the abdomen if the initial postoperative course is not uneventful since full-thickness perforation of the colon may be delayed in its presentation.

Accidents, Occupational↗
PubMed2002

Methods for estimating the transfer efficiency of a compressed air spray gun.

The transfer efficiency of a compressed air spray gun is an important performance index with regard to worker health, environmental, and economic considerations. It is defined as the fraction of paint sprayed that coats the surface. Worker exposure has been identified as a function of the transfer efficiency based on total mass of paint sprayed, which can be predicted by a mathematical model developed with nonvolatile oil. This study extends the existing model to include volatile effects by employing a mathematical approach based on a mass balance. This method allows the current model to predict transfer efficiency bounds at two extreme situations: all volatile compounds evaporate either before or after droplet impaction. Model predictions show that tight transfer efficiency bounds are obtained, especially for high values of transfer efficiency. Thus, the average of the upper and lower bounds should be a reasonable estimate of transfer efficiency. It is also found that the current model prediction, which is based on total mass of paint sprayed, for nonvolatile material can be converted to a transfer efficiency based on the mass of solids. The laboratory study shows that the predicted transfer efficiency based on the mass of solids is within the 95 percent C.I. of the measured value. This work relates the transfer efficiency used in industry, which is calculated on the basis of paint solids, with a model that predicts worker exposure during spray painting operations.

Air Movements↗
PubMed1999

Magnetic resonance signal abnormalities and neuropsychological deficits in elderly compressed-air divers.

We investigated the association between MR signal abnormalities of the central nervous system, neuropsychologic performance and exposure indices in 20 experienced elderly compressed-air divers who had no history of neurological decompression illness (DCI). Results of MRI of the brain and psychometric testing were compared with 20 matched healthy commercial employees who never dived: 60% of the divers and 45% of the controls had hyperintense MR abnormalities. Among divers, both the number and the size of abnormalities correlated with hours diving in the deep air-diving range of 40-60 m (p < 0.05). Divers' mental flexibility and visual tracking performance were decreased in comparison with controls (p < 0.05 and p < 0.01). Divers thus are at risk of detrimental long-term effects of compressed-air diving on the central nervous system even in the absence of a history of neurological DCI.

Barotrauma↗
PubMed2002

Nitric oxide contamination of hospital compressed air improves gas exchange in patients with acute lung injury.

OBJECTIVE: We tested the hypothesis that NO contamination of hospital compressed air also improves PaO(2) in patients with acute lung injury (ALI) and following lung transplant (LTx). DESIGN: Prospective clinical study. SETTING: Cardiothoracic intensive care unit. PATIENTS: Subjects following cardiac surgery (CABG, n=7); with ALI (n=7), and following LTx (n=5). INTERVENTIONS: Four sequential 15-min steps at a constant FiO(2) were used: hospital compressed air-O(2) (H1), N(2)-O(2) (A1), repeat compressed air-O(2) (H2), and repeat N(2)-O(2) (A2). MEASUREMENTS AND RESULTS: NO levels were measured from the endotracheal tube. Cardiorespiratory values included PaO(2) were measured at the end of each step. FiO(2) was 0.46+/-0.05, 0.53+/-0.15, and 0.47+/-0.06 (mean+/-SD) for three groups, respectively. Inhaled NO levels during H1 varied among subjects (30-550 ppb, 27-300 ppb, and 5-220 ppb, respectively). Exhaled NO levels were not detected in 4/7 of CABG (0-300 ppb), 3/6 of ALI (0-140 ppb), and 3/5 of LTx (0-59 ppb) patients during H1, whereas during A1 all but one patient in ALI and three CABG patients had measurable exhaled NO levels (P<0.05). Small but significant decreases in PaO(2) occurred for all groups from H1 to A1 and H2 to A2 (132-99 Torr and 128-120 Torr, P <0.01, respectively). There was no correlation between inhaled NO during H1 and exhaled NO during A1 or the change in PaO(2) from H1 to A1. CONCLUSIONS: Low-level NO contamination improves PaO(2) in patients with ALI and following LTx.

Air↗
PubMed1993

Compressed air diving and respiratory disease. A discussion document of the Thoracic Society of Australia and New Zealand.

OBJECTIVE: To review the pathophysiology and respiratory complications of compressed air diving, and to formulate guidelines for assessing respiratory fitness to dive so that diving candidates can be advised of the risks associated with respiratory disease, in particular asthma. DATA SOURCES: Specialist medical journals in the areas of respiratory medicine, physiology and diving medicine. Morbidity and mortality statistics were obtained from international diving bodies, diving medicine scientific meetings, and papers. SYNTHESIS: The major complications of underwater diving in subjects with compromised respiratory function are drowning, pulmonary barotrauma and arterial gas embolism. Diving candidates with a history of asthma, pneumothorax, obstructive or restrictive lung disease, lung cysts or thoracic trauma should be advised not to dive in view of these risk factors. CONCLUSIONS: Several respiratory diseases carry an increased risk of morbidity and mortality from compressed air diving. An accurate history and measurement of lung function are an essential part of assessing fitness to dive, both to advise potential divers appropriately and to reduce risks associated with this increasingly popular recreational activity.

Asthma↗
PubMed2006

Bilateral orbital emphysema and pneumocephalus as a result of accidental compressed air exposure.

Orbital emphysema is a rare condition in the absence of trauma or sinus disease. A 22-year-old man suffering from left orbital trauma due to sudden exposure to compressed air tube was admitted with severe pain in the left eye, swelling, and mild periorbital ecchymosis. Physical examination revealed a large conjunctival laceration in the left orbit. Multislice computed tomographic scanning of the head and orbits showed extensive radiolucencies consistent with the air in both orbits, more prominent in the left. There was also subcutaneous air in the left periorbital soft tissue extending through fronto-temporal and zygomatic areas. Air was also demonstrated adjacent to the left optic canal and within the subarachnoid space intracranially. There was no evidence of any orbital, paranasal sinus, or cranial fracture. Visual acuity was minimally decreased bilaterally. The conjunctiva was sutured under local anesthesia. After 3 weeks of follow-up, the patient completely recovered without visual loss. Bilateral orbital emphysema with pneumocephalus can occur from a high-pressure compressed air injury after unilateral conjunctival trauma without any evidence of fracture.

Adult↗
PubMed1988

Manifestations and treatment of 793 cases of decompression sickness in a compressed air tunneling project in Hong Kong.

In the largest compressed air tunneling contract for the construction of the Island Line of the Mass Transit Railway system in Hong Kong, 154,390 man-decompressions occurred, of which 142,140 were after exposures to 1 bar (1.97 ATA, 14.7 psig) or above. The maximum working pressure (MWP) was 3.30 bar (4.26 ATA, 47.9 psig). There were 792 cases of type I and 1 case of type II decompression sickness. The manifestations of the cases were generally similar to those reported elsewhere. Oxygen treatment was given to 9 cases and all were successfully treated with no recurrence of symptoms. Minimum effective pressure treatment on 783 type I cases was successful, with 9.6% requiring two or more recompressions. The pressure required to relieve symptoms was more closely related to the interval between completion of decompression after work and commencement of treatment than to the delay between onset of symptoms and treatment. For every 1-h interval or every 1-h delay, an additional pressure of 0.04 bar (0.04 ATA, 0.58 psi) above MWP was required for pain relief. Step-wise multiple regression analysis showed that the four predictors for pressure of relief and the highest pressure used in recompression, respectively, were, in order of descending importance, maximum working pressure, interval before treatment, bends sequence (the nth attack of bends experienced in the present contract, i.e., the sum of previous attacks and the present attack), and duration of exposure.

Adult↗
PubMedDate not supplied

Tissue-space emphysema, tissue necrosis, and infection following use of compressed air during pulp therapy: case report.

The intraoperative development of tissue-space emphysema in a child undergoing restorative treatment under general anesthesia is presented. Emphysema development seems to be concomitant with the use of compressed air around patent root canals, complicated by tissue destruction due to movement of canal irrigants/medicaments into the periapical tissues and by secondary infection. Several recommendations for the prevention of tissue-space emphysema are presented including the use of a rubber dam, judicious use of compressed air, and maintenance of canal irrigants and medicaments within the root canal. Treatment recommendations vary from palliative care with follow up in cases of facial emphysema to immediate medical attention in cases of pharyngeal or mediastinal emphysema.

Abscess↗
PubMed1989

Reducing fire hazard during ophthalmic surgery by using compressed air.

The use of oxygen increases the risk of fire during ophthalmic surgery. A prospective clinical study was conducted involving 100 patients without pulmonary disease who had cataract surgery under local anesthesia using either oxygen or compressed air. No clinically significant difference in oxygen saturation between the two groups was found. There was no statistically significant difference in the net change in saturation, and the significant difference found in overall mean saturation between the two groups was invalidated by inherent machine error. Using compressed air instead of oxygen is suggested to reduce fire hazard during ophthalmic surgery.

Air↗