PubMed HealthSearch

PubMed · 2178958

Respiratory changes with deep diving.

Abstract

Deep diving refers to saturation diving to a depth of more than 180 m (1.9 MPa ambient pressure). In the 1990s diving to 400 m may be necessary on the Norwegian continental shelf. The safety margins are narrow and the respiratory system is subject to great strain at such depths. The respiratory resistance increases and the dynamic lung volumes are reduced as the pressure increases due to enhanced gas density. Helium is used together with oxygen as breathing gas and its lower density partly normalises the dynamic lung volumes. The respiratory system puts clear limitations on intensity and duration of physical work in deep diving. Systematic studies of lung mechanics, gas exchange and respiratory regulation in the different phases of deep dives are lacking. Detection of occupational respiratory disorder following diving are dependent on long-term follow-up.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

K Segadal, A Gulsvik, G Nicolaysen. 1990. Respiratory changes with deep diving.. https://pubmed.ncbi.nlm.nih.gov/2178958/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Nitrogen tensions in brachial vein blood of Korean ama divers.

Intravascular bubble formation and symptoms of decompression sickness have been reported during repetitive deep breath-hold diving. Therefore we examined the pattern of blood N2 kinetics during and after repetitive breath-hold diving. To study muscle N2 uptake and release, we measured brachial venous N2 partial pressure (PN2) in nine professional Korean breath-hold divers (ama) during a 3-h diving shift at approximately 4 m seawater depth and up to 4 h after diving. PN2 was determined with the manometric Van Slyke method. Diving time and depth were recorded using a backpack computer-assisted dive longer that allowed calculating the surface-to-depth time ratio to derive the effective depth. With the assumption that forearm muscle N2 kinetics follow the general Haldanian principles of compression and decompression, i.e., forearm muscle is a single compartment with a uniform tissue PN2 equal to venous PN2, PN2 data were fitted to monoexponential functions of time. In the early phase of the diving shift, PN2 rapidly increased to 640 Torr (half time = 6 min) and then slowly declined to baseline levels (half time = 36 min) after the work shift. Peak PN2 levels approximated the alveolar PN2 derived from the effective depth. We conclude that forearm muscle N2 kinetics are well described by a Haldanian single-compartment model. Decompression sickness is theoretically possible in the ama; it did not occur because the absolute PN2 remained low due to the shallow working depth of the ama we studied.

Diving

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