Hyperbaric pressure - 211 entries found
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Government Order of 15 May 1992 on the procedures relating to access to, staying in, egress from and work organization in hyperbaric atmospheres [France]
Arrêté du 15 mai 1992 définissant les procédures d'accès, de séjour, de sortie et d'organisation du travail en milieu hyperbare [France] [in French]
This Order (published in the French Journal officiel of 26 June 1992, pp.8413-8416) lays down instructions for the access to, staying in, egress from and organization of work in hyperbaric atmospheres in France, including: intervention procedures in subaquatic settings; hyperbaric intervention procedures without immersion; preventive and emergency measures; final provisions.
Documents pour le médecin du travail, 3rd Quarter 1992, No.51, p.429-431.
Conkin J., Bedahl S.R., Van Liew H.D.
A computerised databank of decompression sickness incidence in altitude chambers
A hypobaric decompression sickness databank (HDSD) for use with personal computers is described. The databank consolidates some of the decompression sickness (DCS) information that has accumulated from altitude chamber tests from 1942 to the present. Data includes details of the test conditions in the altitude chamber, outcome of the test, physical characteristics of the test subjects, and denitrogenation procedures prior to decompression. The HDSD currently contains 378 records representing 130,012 altitude exposures.
Aviation, Space, and Environmental Medicine, Sep. 1992, Vol.63, No.9, Section 1, p.819-824. 12 ref.
The role of ground level oxygen in the treatment of altitude chamber decompression sickness
Data were collected on the use of ground-level oxygen in the treatment of altitude chamber decompression sickness among US Air Force personnel during 1989-91. Data included age, sex, time of symptom development, type of initial treatment and response to ground-level oxygen administration. Of the 175 cases treated with ground-level oxygen, 40 failed to resolve and were treated with compression therapy. The remaining 135 all resolved with ground-level oxygen, obviating the need for hyperbaric oxygenation. Factors associated with a favourable response to this type of treatment are discussed.
Aviation, Space, and Environmental Medicine, Dec. 1992, Vol.63, No.12, p.1102-1105. 12 ref.
Kumar K.V., Waligora J.M., Gilbert J.H.
The influence of prior exercise at anaerobic threshold on decompression sickness
In a study to examine the effects of exercise prior to decompression on the incidence of altitude decompression sickness (DCS), 39 subjects exercised at their predetermined anaerobic threshold levels for 30min each day for three days prior to exposure to an altitude of 6,400m in a hypobaric chamber. No significant difference in DCS preferences was found.
Aviation, Space, and Environmental Medicine, Oct. 1992, Vol.63, No.10, p.899-904. 26 ref.
Hamilton K., Laliberté M.F., Heslegrave R.
Subjective and behavioural effects associated with repeated exposure to narcosis
In a study of nitrogen narcosis in divers, symptoms and performance were examined over the course of five days of repeated exposure to 30% nitrous oxide at 1 atmosphere. While the results revealed no meaningful decrease in global perceptions of narcosis, some narcotic symptoms showed clear signs of adaptation. However, with respect to performance effects, reaction time yielded no indications of improvement. The findings suggest that subjective adaptation can occur without parallel performance improvement, an effect which could compromise safety and which may be of concern in other operational settings where conditions may have an impact on performance and symptoms.
Aviation, Space, and Environmental Medicine, Oct. 1992, Vol.63, No.10, p.865-869. 25 ref.
Melamed Y., Shupak A., Bitterman H.
Medical problems associated with underwater diving
The underwater environment, with its rapidly changing ambient pressures, presents pathophysiological challenges that may lead to a variety of unusual diseases for which rapid diagnosis and treatment are critical. Barotrauma, which refers to tissue injury resulting from the failure of a gas-filled body space (e.g. the lungs, the middle ear, and the sinuses) to equalise its internal pressure to correspond to ambient pressure changes, is discussed. Other medical conditions covered include nitrogen narcosis and Types I and II decompression sickness. Type I decompression sickness involves a mild insult; Type II may lead to permanent neurological injury and death. The article reviews symptoms associated with the various conditions, and covers first aid and therapeutic responses.
New England Journal of Medicine, 2 Jan. 1992, Vol.326, No.1, p.30-35. Illus. 51 ref.
Edmonds C., Lowry C., Pennefather J.
Diving and subaquatic medicine
Textbook aimed at doctors and paramedics working with divers who venture on or under the sea. Contents: history of diving; the physics, physiology and technology of diving; the diver and the undersea environment (stress, panic and fatigue, the female diver, undersea environments, the reasons why divers die); dysbaric diving diseases (pulmonary barotrauma, other barotraumas, decompression sickness, dysbaric osteonecrosis); abnormal gas pressures; underwater hazards (drowning and near-drowning, cold and hypothermia, infections, attacks by marine creatures, underwater explosions); other diving disorders (sudden cardiac death syndromes, ear disorders, hearing damage and vertigo, psychological and neuropsychological disorders, other health problems, drugs and diving); diving accidents (unconsciousness, first aid and emergency medical treatment, investigation of diving accidents, medical standards); related subjects (deep and saturation diving, hyperbaric medicine and equipment, submarine medicine). In the annexes: decompression tables (UK, USA, France); diving tables; recompression and saturation therapy tables (US Navy); Comex therapy tables; Australian underwater oxygen tables; flowchart used in treating decompression sickness.
Butterworth / Heinemann, Linacre House, Jordan Hill, Oxford OX2 8DP, United Kingdom, 3rd ed., 1991. x, 565p. Illus. Bibl.ref. Index. Price: GBP 49.50.
Fowler B., Pang E., Mitchell I.
On controlling inert gas narcosis
Ten subjects breathed experimental mixtures of 20% and 35% nitrous oxide (N2O) balanced with oxygen and then aligned a pointer with a target using vision, kinesthesis, or combinations of these senses. N2O did not influence the variable or constant error, but perceptual conditions influenced the variable error and the absolute constant error. Previously demonstrated changes in the variability and accuracy of alignment in this task under N2O are indicative of changes in response bias and/or attention rather than in perceptual sensitivity. The safety and efficiency of divers exposed to narcosis could be improved with training.
Human Factors, Feb. 1992, Vol.34, No.1 p.115-120. Illus. 16 ref.
Lam T.H., Yau K.P.
Dysbaric osteonecrosis in a compressed air tunnelling project in Hong Kong
In a compressed air tunnelling project using the Blackpool Decompression Tables in Hong Kong, radiological examination of the major joints of 912 workers revealed 12 definite and 30 suspected cases of dysbaric osteonecrosis. The infrequent occurrence of osteonecrosis in Hong Kong in general and in this project in particular suggests that the Blackpool Tables were relatively effective in preventing the disease. However, it is concluded that because of the difficulties of long-term follow-up, the prevalence of osteonecrosis in Hong Kong may be under-reported.
Occupational Medicine, Feb. 1992, Vol.42, No.1, p.23-29. 10 ref.
Fueredi G.A., Czarnecki D.J., Kindwall E.P.
MR findings in the brain of compressed-air tunnel workers: Relationship to psychometric results
Cranial magnetic resonance (MR) imaging was performed in 30 compressed-air tunnel workers: 19 who had been exposed to various degrees of hyperbaric air, and 11 age-matched, non-exposed controls. Exposed subjects had more than 152 white matter lesions, compared to 22 in the control group; 37% of the exposed group had more than 20 white matter lesions each, while only 18% of the control group had 10 or 11 lesions each. The exposed group also had a higher risk of high-grade lesions. There was no significant difference between the exposed and control groups in the results of five psychometric tests.
American Journal of Neuroradiology, Jan./Feb. 1991, Vol.12, p.67-70. Illus. 13 ref.
Pipe driving: Safety requirements as seen by safety engineers
Rohrvortriebe: sicherheitstechnische Anforderungen aus der Sicht des Sicherheitsingenieurs [in German]
Pipe driving is a special form of tunnelling. A vertical shaft is driven to the level at which the pipes are to be laid. This level can be as deep as 20m. From the bottom of this shaft pipe segments are advanced in a horizontal direction by hydraulic jacks. Hazards and safety requirements are outlined for work involving pipes larger than 800mm. Protection against welding fumes, fault currents and overpressure are discussed in greater detail. Overpressure is used to hold loose ground in place. A depressuring chart is presented.
Tiefbau-Berufsgenossenschaft, Dec. 1991, Vol.103, No.12, p.836, 838-844. Illus. 2 ref.
Resistance against high-voltage, low-current dry arc for electrical insulating materials of organic solids in pressurised air
Kaatsu kūkichū ni okeru yūki zetsuen zairyō no kōden'atsu shōdenryū āku ni taisuru [in Japanese]
Standards for insulators, such as ASTM D-495 or JIS K-6911, determine arc resistance at atmospheric pressure. Such criteria may not provide adequate protection when electrical equipment is used in caissons or other high-pressure environments. High-voltage, low-current, dry arc resistance of organic insulating materials was investigated in dry air compressed up to 1.9MPa by slightly modified versions of the ASTM and JIS methods. Specimens tested were a melamine-glass laminated sheet, an epoxy-glass laminated sheet, a phenolic-resin sheet, an ABS-resin sheet and a poly-carbonate resin sheet. When pressure increased, the arc-resistance time of most specimens dropped sharply down to almost one tenth of that under the ordinary atmospheric pressure. The reason is that the electric arcs approach more closely the surface of the test specimen with increasing atmospheric pressure and thereby accelerate carbonisation of the specimen.
Research Reports of the Research Institute of Industrial Safety, 10 May 1991, p.75-87. Illus. 6 ref.
Ministère du travail, de l'emploi et de la formation professionnelle
Order of 20 Aug. 1991 prescribing exemptions to the age limit for applying for a certificate of competence for work in hyperbaric atmospheres [France]
Arrêté du 20 août 1991 fixant les conditions de dérogation à l'âge limite pour postuler au certificat d'aptitude à l'hyperbarie [France] [in French]
The age limit for applying for the first time for a certificate of competence for work in hyperbaric atmospheres under the terms of the French regulations (class 1 and 2 for grades C and D, see article 1 of the order of 28 Jan. 1991 (under CIS 91-1775)) is, subject to medical aptitude, raised to 55 years.
Journal officiel de la République française, 30 Aug. 1991, Vol.123, No.202, p.11397-11398.
Bason R., Yacavone D., Bellenkes A.H.
Decompression sickness: USN operational experience 1968-1989
During the period January 1969 to December 1989 decompression sickness was reported in 12 US Navy aircraft and involved 15 aircrew. The primary cause of decompression was a loss of cabin or cockpit pressurisation. The most common manifestation of decompression sickness was limb or joint pain, although some crew members experienced various manifestations of neurological dysfunction and one crewmember experienced chokes. Of the 15 afflicted aircrew, 13 had complete remission of symptoms by the time they landed, while 2 required compression therapy. Recommendations are given concerning the disposition of aircrew who develop decompression sickness.
Aviation, Space, and Environmental Medicine, Oct. 1991, Vol.62, No.10, p.994-996. 10 ref.
Decompression sickness presenting as optic neuropathy
Report of a case of acute optic nerve dysfunction seen in a parachutist after repeated hypobaric exposures. The patient made 2 to 4 high altitude exposures per day for 4 days in an unpressurised aircraft at a maximum altitude of 3,636-3,939m. Resultant symptoms included persistent headache, paracentral scotoma and decreased visual acuity in the left eye. Symptoms improved promptly following treatment with recompression and hyperbaric oxygen therapy. This is believed to be the first case of decompression sickness presenting as optic neuropathy.
Aviation, Space, and Environmental Medicine, Apr. 1991, Vol.62, No.4, p.346-350. Illus. 11 ref.
Olson R.M., Krutz R.W.
Significance of delayed symptom onset and bubble growth in altitude decompression sickness
In order to explain certain characteristics of altitude induced decompression sickness (DCS), in vitro techniques were used to measure bubble growth at various altitudes. Results indicate that although the growth rate of bubbles depends on the altitude where they form, bubble growth requires time, thus explaining in part why symptoms occur some time after arrival at altitude. Bubbles stop growing early at a small size below 18,000ft (5,500m), thus symptoms seldom occur below this height. Finally, since bubbles stop growing when the fluid surrounding the bubble is cleared of supersaturated gas, symptoms seldom occur after 4 hours at altitude.
Aviation, Space, and Environmental Medicine, Apr. 1991, Vol.62, No.4, p.296-299. Illus. 6 ref.
Government Order of 28 March 1991 on recommendations to occupational physicians responsible for medical supervision of work under hyperbaric conditions [France]
Arrêté du 28 mars 1991 sur le travail en milieu hyperbare - Recommandations aux médecins du travail chargés de la surveillance médicale [France] [in French]
The appendix to this order contains recommendations to physicians responsible for the medical supervision provided for in the Decree of 28 March 1990 (see CIS 90-1086), and also a list of special supplementary examinations. The order of 4 October 1974 is repealed.
Cahiers de notes documentaires - Sécurité et hygiène du travail, 3rd Quarter 1991, No.144, Note No.1847-144-91, p.535-538. Appendix.
Rush W.L., Wirjosemito S.A.
Decompression sickness: Risk factors and the monoplace chamber - A case report
This case report of serious decompression sickness (DCS) with pulmonary and neurological manifestations illustrates the principles and concerns related to the use of monoplace chambers for the treatment of DCS. Closely timed recurrent altitude exposure is discussed as a risk factor for DCS, and a newly defined risk factor associated with the menstrual phase is considered relevant to this case. It is recommended that arrangements be made early in the management of DCS cases for transfer to a chamber which can provide definitive therapy.
Aviation, Space, and Environmental Medicine, May 1991, Vol.62, No.5, p.414-417. 19 ref.
Ministère du travail, de l'emploi et de la formation professionnelle
Order of 28 January 1991 on work in hyperbaric atmospheres and safety training [France]
Arrêté du 28 janvier 1991 sur le travail en milieu hyperbare et la formation à la sécurité [France] [in French]
This Order (published in the Journal officiel of 2nd March 1991) lays down instructions for the safety training of employees required to work in hyperbaric conditions: list of activities concerned; requirements for approval of training organisation; conditions under which establishments may be authorised to dispense safety training themselves; presentation requirements for the personal booklet; appointment and training of head of operation and person in charge of control room; appointment of rescue personnel. Appendices provide a list of activities carried out in hyperbaric conditions, training objectives for different activities and a list of diplomas awarded.
Cahiers de notes documentaires - Sécurité et hygiène du travail, 1st Quarter 1991, No.143, Note No.1834-143-91, p.293-299.
Acute decompression sickness in compressed air workers
A brief article on the occurrence of decompression sickness in compressed air environments and the use of decompression tables such as the Blackpool Decompression Tables in the UK. At present there is no decompression procedure that will protect all workers at all times from decompression sickness. Effects have been reported among workers exposed to less than one bar gauge pressure in underground tunnels.
Singapore Medical Journal, 1990, Vol.31, p.99-100. 7 ref.
Yu Y.L., Chang C.M., Lam T.H., Ho K.M., Mok K.Y.
Cervical spondylotic radiculopathy precipitated by decompression sickness
Case study of cervical spondylotic radiculopathy (characterised by neck and shoulder pain, muscle twitching and paralysis of all four limbs) precipitated in a 52yrs old man by work in a compressed-air environment (tunnelling).
British Journal of Industrial Medicine, Nov. 1990, Vol.47, No.11, p.785-787. Illus. 20 ref.
Relationship of menstrual history to altitude chamber decompression sickness
Records at the USAF School of Aerospace Medicine were reviewed to determine the relationship between the incidence of altitude chamber decompression sickness (DCS) in females and menstrual history. A significant inverse linear correlation was noted between the number of days since the start of the last menstrual period and the incidence of DCS. The underlying mechanism for the correlation between menstrual cycle and susceptibility to development of DCS is unknown. It is concluded that women are at higher risk of developing altitude related DCS during menses, with the risk decreasing linearly as the time since last menstrual period increases.
Aviation, Space, and Environmental Medicine, July 1990, Vol.61, No.7, p.657-659. Illus. 7 ref.
Devine J.A., Forte V.A., Rock P.B., Cymerman A.
The use of typanometry to detect aerotitis media in hypobaric chamber operations
Diagnosis and quantification of aerotitis media were performed using a modified commercially-available tympanometer under hypobaric conditions. Subjects were 22 males and 9 females, 22-43 years of age, who were tested in each ear with the tympanometer prior to and after exposure, sequentially at the barometric pressue plateaus of 706, 656, 609, 586, 564, and 522mm Hg, and following an induced ear block during a 1-min descent from 522 to 586mm Hg. Each subject was examined once either alone or in pairs during a 90-min exposure. Aerotitis media was detected using tympanometry at simulated altitude as evidenced by the difference between measurements made during induced ear blocks and those made prior to inducement, as well as following relief of the pressure differential with the Valsolva manoeuvre. There were no significant differences between pre- and post-induced aerotitis media values at 586mm Hg, or between pre- and post-hypobaria. Thus, tympanometry can be a valuable tool in managing aerotitis media in the aeromedical environment.
Aviation, Space, and Environmental Medicine, Mar. 1990, Vol.61, No.3, p.251-255. Illus. 20 ref.
This article reviews the physiology of diving injuries and the preferred methods of treatment. Basic volume/pressure and concentration/pressure properties of gases are explained to show how injuries such as arterial gas embolus (burst lung) and decompression sickness may occur as a result of pressure imbalances within the diver. Details are given of incidents involving diving accidents and the treatment used. Advice is given on the management of serious diving injuries along with the principles and use of hyperbaric oxygen therapy.
Occupational Health in Ontario, Summer 1990, Vol.11, No.3, p.96-105. 4 ref.
Mathieu D., Mathieu-Nolf M., Wattel J.F., Delmas C., Laurent P., Frimat P., Furon D.
Prevention of decompression accidents caused by work in compressed air
Prévention des accidents de décompression dus au travail en air comprimé. Expérience du chantier du métro de Lille [in French]
During work on the Lille (France) underground railway, a particular tunnelling technique was used: mud-pressure tunnelling. This technique requires workers to stay in a hyperbaric chamber. Physicians of the Hyperbaric Oxygen Therapy Centre, having been consulted by doctors of the construction site, developed a programme for the prevention of accidents related to work in a pressurised atmosphere. The programme, which requires close collaboration by occupational physicians, factory inspectors, foremen, emergency services, the fire brigade and the contractor, was highly successful. There were no decompression accidents at all. The development of such programmes is strongly recommended.
Archives des maladies professionnelles, 1990, Vol.51, No.1, p.1-5. 16 ref.
Ministère du travail, de l'emploi et de la formation professionnelle
Decree No.90-277 of 28 March 1990 concerning the protection of workers operating under hyperbaric conditions [France]
Décret n°90-277 du 28 mars 1990 relatif à la protection des travailleurs intervenant en milieu hyperbare [France] [in French]
The provisions of this law are applicable to: means of access to pressurised environments, respirable gases, collective equipment, personnel breathing apparatus, safety procedures, medical supervision. The text is reproduced from the Journal officiel of 29 March 1990.
Bulletin officiel du Ministère du travail, de l'emploi et de la formation professionnelle, 25 May 1990, No.90/7, p.5-16.
Psychosensorimotor work capacity in man under hyperbaric conditions of 6 and 7 absolute atmospheres
Capacité de travail psychosensorimotrice chez l'homme en ambiance hyperbare à l'air à 6 et 7 atmosphères absolues [in French]
Psychophysiological performance is altered in deep diving with air. Considering the differences in legislative requirements among European countries concerning maximal authorised depth in professional diving with air, psychophysiological performance at these depth was evaluated using psychometric determinations of manual skills, visual reactions and ordering of numbers. Performance was altered at depths of 50m and more significantly at 60m. The percentage of divers whose capabilities were reduced increased, for each test, at depths of between 50 and 60m. Under the experimental conditions studied, 50m cannot be considered as a satisfactory depth for the preservation of work capabilities, because it is impossible to predict for a given subject how he/she will react.
Archives des maladies professionnelles, 1989, Vol.50, No.4, p.335-337. 7 ref.
Are the Federal German regulations on compressed-air work still up to date?
Ist die Druckluftverordnung noch zeitgemäss? [in German]
German (Rep.Fed.) legislation on diving and work in compressed air is reviewed in the light of current knowledge in physiology, medicine and safety engineering. It is recommended to update the existing regulations of 1972, 1977 and 1979.
Zentralblatt für Arbeitsmedizin, Arbeitsschutz, Prophylaxe und Ergonomie, 1989, Vol.39, No.4, p.100-104. Illus. 12 ref.
Moon R.E., Camporesi E.M., Kisslo J.A.
Patent foramen ovale and decompression sickness in divers
Examination of 30 patients (all professional or sport scuba divers) with a history of decompression sickness showed that the presence of patent foramen ovale, even in the absence of other evidence of cardiac disease, seems to be a risk factor for the development of decompression disease in divers.
Lancet, 11 Mar. 1989, Vol.1, No.8637, p.513-514. 10 ref.
Work in pressurised atmosphere in a contaminated environment
Arbeiten unter Überdruck in kontaminierter Umgebung [in German]
The environment (water, air) of workers working in a pressurised atmosphere may be polluted by gases such as CO and nitrogen oxides, dust and radioactive substances such as radon. These pollutants can also be present in the air supplied to divers. In tunnelling and caisson work, noise and heat exposure can also occur. Safety measures include air cleaning and the wearing of protective equipment.
Tiefbau-Berufsgenossenschaft, 1989, Vol.101, No.5, p.370, 372-376. Illus.
Polkinghorne P.J., Sehmi K., Cross M.R., Minassian D., Bird A.C.
Ocular fundus lesions in divers
Retinal fluorescein angiography was used to examine the ocular fundi of 84 divers. The divers had significantly more abnormalities of the retinal pigment epithelium than a comparison group of non-divers. The prevalence of fundus abnormality was related to length of diving history. All observed changes were consistent with vascular obstruction, which could be due either to intravascular bubble formation during decompression, or to altered behaviour of blood constituents and blood vessels in hyperbaric conditions.
Lancet, 17 Dec. 1988, Vol.II, No.8625, p.1381-1383. Illus. 25 ref.
Mekjavic I.B., Banister E.W., Morrison J.B.
Environmental ergonomics: sustaining human performance in harsh environments
This book containing a selection of papers presented at the 2nd International Environmental Ergonomics Conference, held at Whistler, British Colombia (Canada), on 21-25 July 1986 offers a collaborative approach to the study of human performance in the face of harsh environments such as equatorial and polar regions, ocean floors and outer space, where hot, cold, wet, high- and low- pressure and other extreme conditions affect the body's physiological and cognitive functions to a significant degree.
Taylor and Francis Ltd., Rankine Road, Basingstoke Hants RG24 OPR, United Kingdom, 1988. 412p. Illus. Bibl. Index. Price: GBP 39.00.
Lam W.K., Tsin T.W., Ng T.P.
Radon hazard from caisson and tunnel construction in Hong Kong
A possible occupational risk of caisson and tunnel excavation in Hong Kong results from the inhalation of natural radon daughters. In this study radon daughter concentrations ranging from 0.001 to 71.4WL were recorded in caissons of various dimensions and from 0.03 to 0.95WL in tunnels over 1km in length under construction (ICRP exposure limit being 0.4WL). There was clear indication of increased radon daughter accumulation in confined and unventilated areas and in unventilated caissons an exponential increase of radon daughter concentrations with the ratio of depth to cross-sectional area was observed (r = 0.9). The study revealed a potential radiation hazard facing underground construction workers and this is being examined by an ongoing epidemiological cohort study: meanwhile environmental control should be improved.
Annals of Occupational Hygiene, 1988, Vol.32, No.3, p.317-323. Illus. 13 ref.
Ailments caused by exposures to high-pressure atmospheres
Kōkiatsu kankyōka ni okeru kenkō shōgai [in Japanese]
Review of work in high-pressure atmospheres (e.g. diving or tunnel work). In this case, excessive pressure changes due to compression or decompression may cause ailments including squeezes of ear, sinus, tooth or lung, burst lung and arterial gas embolism, oxygen poisoning, nitrogen narcosis, high pressure nervous syndrome (HPNS), decompression sickness and dysbaric osteonecrosis. Cause, signs and symptoms, treatment and prevention of these diseases are described. Official Japanese decompression tables are presented.
Occupational Health Journal, Feb. 1988, Vol.11, No.2, p.4-14. 7 ref.
Lam T.H., Yau K.P.
Medical examination and surveillance of compressed air workers in Hong Kong
In Hong Kong, compressed air was used in the construction of underground tunnels for the Mass Transit Railway. From 1982 to 1984, 1,916 men had an initial medical examination before employment in compressed air work. 367 men were declared unfit for employment resulting in an unfit rate of 19.2%. The major disqualifying conditions were diseases of the lung and the cardiovascular system. Chest X-ray was found to be the most useful procedure since it revealed 55% of the total disqualifying conditions. Of the 1,549 men declared fit for employment, 130 (8.4%) were later declared unfit to continue, mainly because of their susceptibility to attacks of bends. The overall bends rate was low (0.57%) and only 3 cases of dysbaric osteonecrosis could be definitely attributed to the present employment. Experience suggests that strict medical criteria for medical examination and surveillance were important in the prevention of decompression sickness and dysbaric osteonecrosis.
Journal of the Society of Occupational Medicine, Spring/Summer 1988, Vol.38, Nos. 1/2, p.9-12. 6 ref.
Ross J.A., Green H.L.
Levels of short (1-15ms) electrical shocks from a 50Hz supply inducing ventricular fibrillation in hyperbaric helium and oxygen
An investigation was undertaken to determine the ventricular fibrillation (VF) threshold of anaesthetised dogs subjected to external application of electric shocks while in a hyperbaric environment of 31 atmospheres absolute (atm abs) in a helium-oxygen atmosphere. The duration and position of the part of the cardiac cycle most vulnerable to induction of VF by electrocution was found (7 animals) using 4ms shocks and then the minimum fibrillating current was determined for shocks of 2-15ms (min FC2-15) delivered at the most vulnerable point of the cycle (5 animals). Body resistance was calculated from the data so gathered. Fibrillation thresholds were not changed by compression and there were no significant changes in the vulnerable period of the cardiac cycle. Min FC2 was significantly higher than for other durations under both control (3.21 A, SD 1.08) and test conditions (3.26 A, SD 0.39), p=0.001. There was no difference in body resistance at 31atm abs (395.5, SD 12.9) from control values at 1atm abs (396.7, SD 10.9). Thus, the heart is no more susceptible to the induction of VF at 31atm abs in a helium-oxygen environment, and no special electrical safety measures are called for.
British Journal of Industrial Medicine, Nov. 1987, Vol.44, No.11, p.764-768. Illus. 13 ref.
Mano Y., Shibayama M., Matsui Y.
Research on the incidence of decompression sickness in compressed air work - Changes in incidence in the last 5 years
Akki doboku sagyō ni okeru gen-atsu-shō hasshōritsu ni kansuru kenkyū - Saikin 5-nen-kan no hasshōritsu sui-i [in Japanese]
The incidence of the bends in caisson and shield workers in Japan was determined for the period 1981-85 and for a period ending in 1980. The average incidence at the time of writing was 0.54%. Previous studies had reported higher incidences (1.42-3.3% or more). The improvement reflects the application of standard decompression schedules by the Ministry of Labour. The fact that cases of decompression sickness are still occurring means that more work by safety specialists remains to be done.
Japanese Journal of Industrial Health - Sangyō-Igaku, July 1987, Vol.29, No.4, p.271-278. Illus. 25 ref.
Shibayama M., Mano Y., Okubo J.
Study of Eustachian tube function in fishermen (oikomi-gyohō) divers
Gyogyō (oikomi-gyohō) daibā no jikan kinō ni kansuru kenkyū [in Japanese]
The intranasal pressure at the opening of the auditory tube was compared by Valsalva's method with that of normal adults under atmospheric pressure to assess the auditory tubal function of divers often exposed to hyperbaric conditions. The mean auditory tube opening pressure was higher in the divers than in the controls. There are 2 ways of accommodating human auditory tubal ventilation: active opening and passive opening - the former is predominant in adults, the latter in children. The function in divers resembles the child type. This finding suggested that their auditory tube might not open and close with each swallowing movement under atmospheric pressure, or the auditory tube and the middle ear themselves no longer needed the opening with each swallowing movement under atmospheric pressure. Moreover, divers take various postures while they are diving, including a head-down posture. The auditory tube opens less readily in the head-down position. This phenomenon appears to represent the effect of hydrostatic venous pressure in water.
Japanese Journal of Industrial Health - Sangyō-Igaku, July 1987, Vol.29, No.4, p.265-270. Illus. 15 ref.
Cruz Gisbert J.M., Peset Pérez R., Marco Artal M.A.
Illness in a diver: A case study
Patología del buzo a propósito de un caso/Patología del buzo a propósito de un caso [in Spanish]
The first part of the article gives a synopsis of the health problems affecting professional divers, due to intoxication from the respiratory gases used, changes in pressure during underwater work, and the combined effects of these two hazards (pulmonary insufflation). The second part is a case study of a 28-year old male professional diver who had been working underwater at a depth of between 3 and 45m during more than 500 hours. He was suffering from pains in the left shoulder, which hindered him in his work. The diagnosis was aseptic osteonecrosis, caused by his underwater work, and leading to permanent invalidity from diving work.
Medicina y seguridad del trabajo, July-Sep. 1987, Vol.34, No.136, p.65-72. 40 ref.
Mano Y., Shirayama M.
Medical aspects of environmental sanitation of places of compressed air work in Japan
Akki doboku sagyōba ni okeru sagyō kankyō kara mita mondaiten [in Japanese]
The incidence of decompression sickness (bends) has decreased in recent years because of strict control by regulations. Environmental hygiene, however, has seldom been discussed and little monitoring has been done. This investigation is the first of its kind in Japan; it covered most of the regions where compressed air work has been done in the past. Follow-up investigations were made for a period of 5yrs 10 months beginning in February 1980 on 55 places of caisson and shield work. The maximum bottom pressure in caisson work was 3.6kg/cm2 (4.6ATA) and that in shield work was 1.6kg/cm2. The number of exposures of workers was 23,737 in caisson work and 75,244 in shield work. The items measured included temperature, humidity, dust, illumination, noise, oxygen and carbon dioxide. Findings: the working temperature was controlled, but humidity was too high (nearly 90%); illumination was insufficient; dust was problem, but high humidity played an important role in limiting dust levels; the environment was noisy.
Japanese Journal of Industrial Health - Sangyō-Igaku, Jan. 1987, Vol.29, No.1, p.74-81. Illus. 31 ref.
Tonczar L., Schlick W.
Diseases due to work in pressurised atmosphere - Diagnosis, prevention, treatment
Drucklufterkrankungen - Diagnose, Prävention und Therapie [in German]
Review of Austrian legislation and terminology. Advice on diagnosis and preventive measures (aptitude tests, testing under pressurised conditions, forbidden work, information, lengthening the decompression period, recompression, medical and pharmaceutical measures).
Österreichische Ärztezeitung, Mar. 1986, Vol.41, n°5, p.26-32. 22 réf.
Regulation made under the Occupational Health and Safety Act: Diving operations [Canada - Ontario]
Applies to every employer, supervisor, worker and constructor engaged in diving operations. Aspects covered: general; equipment; medical and emergency procedures; S.C.U.B.A. (self-contained underwater breathing apparatus) diving; surface-supply diving; deep diving; special hazards; diving records.
Ontario Gazette - Gazette de l'Ontario, 15 Nov. 1986, Vol.119-46, p.2294-2306.
Leitch D.R., Green R.D.
Pulmonary barotrauma in divers and the treatment of cerebral arterial gas embolism; Recurrent pulmonary barotrauma
A review of case reports spanning 20 years of diving incident records kept at the UK Institute of Naval Medicine revealed 140 cases of decompression pulmonary barotrauma (PBT) among divers breathing compressed air. Article 1 analyses the cases (23 cases of uncomplicated PBT and 117 cases of cerebral arterial gas embolism (AGE)) and their treatment. Article 2 considers the 12 cases of recurrence separately: they were more serious than the first occurrence of the condition, and more likely to include AGE. It is concluded that divers who suffer PBT, regardless of cause or lack of severity, should not be allowed to dive again. Routine screening by simple spirometry did not influence the PBT rate, and its usefulness must be questioned.
Aviation, Space, and Environmental Medicine, Oct. 1986, Vol.57, No.10, Section I, p.931-938; Nov. 1986, Vol.57, No.11, p.1039-1043. 32 ref.
Diseases due to differences in environmental pressure
Maladies dues à des variations de la pression ambiante [in French]
The 2 parts of this very detailed document present the following subjects: physical principles and laws; sources of risk (diving, high-pressure environments, high altitudes); pathogenesis and clinical tables (barotrauma, effects of gases dissolved in the body under increased pressure, gas bubbles in blood and body tissue during a rapid fall in air pressure, effects of oxygen deprivation, deaths during diving); medical and therapeutic prevention; insurance law; accident rates; legal case studies.
Caisse nationale suisse d'assurance en cas d'accidents, case postale, 6002 Luzern, Switzerland, Sep. 1986, n°8, 2 parts, 139p. Illus. 37 ref.
Medical surveillance of diving work
Medicinsk kontroll vid dykeriarbete [in Swedish]
These regulations (effective 1 Jan. 1987) apply to work under water and in pressurised atmospheres, i.e. in pressurised tanks or caissons. Contents: prohibition to employ pregnant women and workers whose states of health may result in accidents or health impairments during diving; pre-employment and periodic medical examinations (at least every 5 years); re-examination after disease or accident. In an appendix: advice for the application of the regulations (health hazards; decompression sickness; barotraumatic damage to the lungs, middle ear, teeth and jaw; poisoning by oxygen, nitrogen, carbon dioxide; hypothermia; treatment) and detailed comentaries.
LiberDistribution, 162 89 Stockholm, Sweden, 5 June 1986. 18p.
Construction work under hyperbaric conditions
Les travaux en conditions hyperbares dans la construction [in French]
Het uitvoeren van bouwwerken onder verhoogde luchtdruk - Les travaux en conditions hyperbares dans la construction [in Dutch]
A review of work in compressed air and related matters (fire rescue, collapses of excavations, intrusion of water or gases) is followed by an evaluation of workload under hyperbaric conditions on 3 different worksites and of the cardiac and respiratory performance of workers during sub-maximal effort in an experimental caisson. These physiological parameters show the importance of the technical preventive measures described in the 1st part of the publication. Decompression tables are appended.
Nationaal Actiecomite voor Veiligheid en Hygiene in het Bouwbedrijf, Poincarelaan 70, 1070 Bruxelles, Belgium, Oct. 1986. 60p. Illus. 49 ref. Price: BF.200.00.
Andrews G., Holt P., Edmonds C., Lowry C., Cistulli P., McKay B., Misra S., Sutton G.
Does non-clinical decompression stress lead to brain damage in abalone divers?
No evidence of cognitive impairment, as evidenced by a battery of neuro-psychological tests, was found in 48 Australian divers, despite many past occurrences of decompression sickness among them. Commercial fishermen who do not dive were used as controls.
Medical Journal of Australia, 14 Apr. 1986, Vol.144, No.8, p.399-401. 10 ref.
Downs G.J., Kindwall E.P.
Aseptic necrosis in caisson workers: a new set of decompression tables
There is a high incidence of aseptic necrosis and decompression sickness among caisson workers due to inadequate decompression using the current OSHA decompression tables (see CIS 83-214). Because of this, a new set of tables - called Autodec III-O2 - was developed. Following this schedule eliminates nitrogen more effectively from the body, thus decreasing the incidence of both bends and aseptic necrosis. The superiority of this schedule over the OSHA table was significant at the 0.08 level.
Aviation, Space, and Environmental Medicine, June 1986, Vol.57, No.6, p.569-574. Illus. 16 ref.
Working conditions in hyperbaric environments - "Ergonomics and high atmospheric pressures"
Les conditions de travail en milieu hyperbare dans la construction, "ergonomie et hyperbarie" [in French]
Evaluation of the effect of heavy workload in 3 types of operations under hyperbaric conditions in the construction industry. The study involved measurements of oxygen consumption, heart rate and respiratory parameters during standardised work tasks under normal and hyperbaric pressure. The results demonstrate the imporance of the composition of pressurised atmospheres, of their hourly renewal and their temperature, and of the relationship between workload and recuperative powers of workers after effort.
Cahiers de médecine du travail - Cahiers voor arbeidsgeneeskunde, 1985, Vol.22, No.4, p.269-282. Illus. 46 ref.
Lam T.H., Yau K.P., O'Kelly F.J.
Dysbaric hazard of a new fishing method in Hong Kong: case report
Case study of a fisherman who developed type-2 decompression sickness symptoms after his makeshift diving equipment failed during a dive to the depth of 37m in search of fish. Hyperbaric oxygen treatment completely cured the condition.
British Journal of Industrial Medicine, Mar. 1985, Vol.42, No.3, p.209-210. Illus.
O'Kelly F.J., Liou N.C.
Medical surveillance of compressed air work support service personnel
A retrospective study of medical examination results connected with workers exposed to compressed air during the building of the Hong Kong Mass Transit Railway. Of the 1030 people who underwent an initial examination, 217 were unfit for such work. During subsequent monthly examinations, 105 workers were found unfit. Radiological surveys of major joints established the cause of unfitness to be bone disease in 31 of those initially found unfit, and in 22 cases later. It is recommended that for compressed air work an initial medical examination is essential, but after that it is sufficient to do routine periodic examinations once a year only.
Journal of the Society of Occupational Medicine, Nov. 1984, Vol.34, No.4, p.124-126.
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