Nitrogen narcosis is a dangerous condition that can affect scuba divers, especially when diving deeper than 30 meters. The exact mechanisms behind nitrogen narcosis are still to be explored, but it has to do with nitrogen gas affecting the nerve transmissions in the body during high pressure. Nitrogen is not the only gas capable of affecting the nerve transmissions when the body experience high pressure; the same state of intoxication can for instance be caused by hydrogen and argon. Since the air inhaled by scuba divers contains a large amount of nitrogen (just like the air that we breathe above the surface every day), nitrogen narcosis was the first type of gas narcosis experienced by scuba divers, hence the name. Today, the condition is also referred to as Inert Gas Narcosis.
The effects of nitrogen narcosis are similar to the effects of anesthetic gas or alcohol. The well known diver Jacques Cousteau expressed it as the “rapture of the deep”. Since a diver needs to be focused and act responsible - and even more so at great depths - nitrogen narcosis can have disastrous effect. A diver can for instance forget to check how much air he or she has left, stay down to long or forget to do safety stops when ascending to the surface. Some divers have even begun to take off their equipment or tried to share their mouth piece with a fish. Nitrogen narcosis can also be lethal due to nitrogen poisoning.
It can be hard for the effected diver to realize that he or she is developing nitrogen narcosis, since the level of intoxication will increase gradually. It is therefore always important to keep an eye on your partner during the dive and try to detect illogical behaviors. Many divers regularly check the mental state of their buddy by showing the buddy a number of fingers. Before the dive, the divers have agreed that when 3 fingers are displayed, the buddy must respond by showing 2 fingers, when 8 fingers are displayed the buddy should hold up 7 fingers and so on. A diver suffering from nitrogen narcosis might calculate the wrong number, or display a number of fingers that is not coherent with the number that he or she calculated. The diver can also loose interest in carrying out these safety checks and ignore the buddy. Read more about Facts of Scuba Diving
05-16-2006
May 24th, 2006 at 11:06 pm
How common is this amongst scubadivers?
May 25th, 2006 at 1:00 am
Nitrogen narcosis is a condition that describes a state of mental and physical impairment that may affect a diver at depth. It is caused by excessive nitrogen that may build up in the brain on descent (usually rapid). It is more common with deeper dives to greater than 50 Meters salt water. If you may recall, some doctors or dentists have used inhaled nitrogen, commonly referred to as “laughing gas,” as a general anesthetic. The mental and behavioral changes of excessive nitrogen exposure may include overconfidence and risk taking, poor attention or concentration, memory impairment, hallucinations, and sleepiness. Vision is commonly affected, with some describing tunnel vision or blurred vision. Physical movements may be uncoordinated and clumsy. In essence, the diver with nitrogen narcosis has become “drunk” under water. The essential risk is due to underwater accidents that may occur due to the diver’s poor judgment and/or physical impairment. Fortunately, narcosis resolves rapidly with controlled ascent.