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Nitrogen Narcosis Avoidance and Cure
zaheer2alvi - 8/14/2007 7:57 AM
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Category: Educational
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Avoidance and cure The most straightforward way to avoid nitrogen narcosis is for a diver to limit the depth of dives. If narcosis does occur, the effects disappear almost immediately upon ascending to a shallower depth. As narcosis gets worse with increasing depth, a diver keeping to shallower depths can avoid serious narcosis. Most recreational dive schools will only certify basic divers to depths of 18 metres (60 feet), and at these depths narcosis does not present a large risk. The second most straightforward way to avoid narcosis is to use gasses that limit or exclude nitrogen like trimix for deeper dives. Specialist training is normally required for certification up to 30 metres (100 feet) on air, and this training should include a discussion of narcosis, its effects, and cure. Some diver training agencies offer speciality training to prepare recreational divers to go to depths of 40 metres (130 ft), often consisting of further theory and some practice in deep dives with close supervision. While the individual diver often cannot predict exactly at what depth the onset of narcosis will occur on a given day, the first symptoms of narcosis for any given diver are often much more predicable and personal. For example, one diver may have trouble with eye focus (close accomodation for middle-aged divers), another may experience feelings of euphoria, and another feelings of claustrophobia. Some divers report that they have hearing changes, and that the sound which their exhaled bubbles make, becomes different. Specialist training may help divers in identifying these personal onset signs, and these may then be used as a signal to ascend to shallower depths. Although it is sometimes true that narcosis interfers with judgement to prevent such decisions, this is by no means always the case.