Nitrogen narcosis: Difference between revisions
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==Background== | ==Background== | ||
* | *Toxic effects of breathing nitrogen-containing gases while at depth | ||
* | *Called the "rapture of the deep" | ||
* | *Develops between 3-4ATM (99-132 feet)<ref name="Grover">Grover CA, Grover DH. Albert Behnke: nitrogen narcosis. J Emerg Med. 2014 Feb;46(2):225-7.</ref> | ||
* | **Rare at depths less than 30 meters (100 ft) unless breathing non-standard air mixtures | ||
**Similar to alcohol, frequent divers can develop tolerance to the effects of nitrogen narcosis<ref name="Grover" /> | |||
*Can be prevented by using nitrogen-free gas mixture (e.g. heliox), or mixtures with reduced nitrogen content (e.g. helium-nitrogen-oxygen)<ref name="Grover" /> | |||
*Risk factors = exertion during dive, cold conditions, alcohol intoxication before dive<ref name="Grover" /> | |||
==Clinical Features== | ==Clinical Features== | ||
* | *Insidious onset of symptoms similar to alcohol intoxication (or nitrous oxide inhalation)<ref name="Grover" /> | ||
* | **Early stage: Euphoria, false sense of security, impaired judgement | ||
**Later stage: Impaired concentration and memory, paresthesias, hallucinations | |||
**Final stage: [Occurs at depths of at least 10-13ATM (333-429 feet)], lethargy and loss of consciousness | |||
*Causes high risk of making bad decisions at depth (cause of up to 9% of diving deaths)<ref name="Grover" /> | |||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
{{Scuba diving DDX}} | {{Scuba diving DDX}} | ||
== | ==Diagnosis== | ||
*Clinical diagnosis | *Clinical diagnosis | ||
==Management== | ==Management== | ||
*Ascent | *Ascent - symptoms completely reversed within minutes by ascending to a shallower depth, with no long-term effect | ||
**Therefore, consider other causes in patients with continued symptoms after ascent | |||
==Disposition== | ==Disposition== | ||
*Discharge | |||
==See Also== | ==See Also== | ||
*[[Scuba diving emergencies]] | |||
==External Links== | ==External Links== | ||
== | |||
==References== | |||
<references/> | <references/> | ||
[[Category:Environ]] | [[Category:Environ]] | ||
Revision as of 02:36, 6 March 2016
Background
- Toxic effects of breathing nitrogen-containing gases while at depth
- Called the "rapture of the deep"
- Develops between 3-4ATM (99-132 feet)[1]
- Rare at depths less than 30 meters (100 ft) unless breathing non-standard air mixtures
- Similar to alcohol, frequent divers can develop tolerance to the effects of nitrogen narcosis[1]
- Can be prevented by using nitrogen-free gas mixture (e.g. heliox), or mixtures with reduced nitrogen content (e.g. helium-nitrogen-oxygen)[1]
- Risk factors = exertion during dive, cold conditions, alcohol intoxication before dive[1]
Clinical Features
- Insidious onset of symptoms similar to alcohol intoxication (or nitrous oxide inhalation)[1]
- Early stage: Euphoria, false sense of security, impaired judgement
- Later stage: Impaired concentration and memory, paresthesias, hallucinations
- Final stage: [Occurs at depths of at least 10-13ATM (333-429 feet)], lethargy and loss of consciousness
- Causes high risk of making bad decisions at depth (cause of up to 9% of diving deaths)[1]
Differential Diagnosis
Diving Emergencies
- Barotrauma of descent
- Otic barotrauma
- Pulmonary barotrauma
- Sinus barotrauma
- Mask squeeze
- Barodentalgia (trapped dental air causing squeeze)
- Barotrauma of ascent
- Pulmonary barotrauma (pulmonary overpressurization syndrome)
- Decompression sickness (DCS)
- Arterial gas embolism
- Alternobaric vertigo
- Facial baroparesis (Bells Palsy)
- At depth injuries
- Oxygen toxicity
- Nitrogen narcosis
- Hypothermia
- Contaminated gas mixture (e.g. CO toxicity)
- Caustic cocktail from rebreathing circuit
Diagnosis
- Clinical diagnosis
Management
- Ascent - symptoms completely reversed within minutes by ascending to a shallower depth, with no long-term effect
- Therefore, consider other causes in patients with continued symptoms after ascent
Disposition
- Discharge