Nitrogen Narcosis Overview
Breathing nitrogen under pressure produces an intoxicating effect known as nitrogen narcosis. Most divers experience symptoms of nitrogen narcosis at depths greater than 100 feet, but symptoms may occur in depths as little as 33 feet. For this reason, use of compressed air deeper than 120 feet is not recommended.
Ascent reverses the symptoms of nitrogen narcosis. Factors that increase the risk of narcosis include cold temperatures, rapid descent, anxiety, alcohol, sedatives, fatigue, and carbon dioxide excess.
Scott H Plantz, MD, FAAEM
N Stuart Harris, MD, MFA
Francisco Talavera, PharmD, PhD
James Kimo Takayesu, MD
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Although decompression sickness (DCS), a complex resulting from changed barometric pressure, includes high-altitude–related and aerospace-related events, this article focuses on decompression associated with the sudden decrease in pressures during underwater ascent, usually occurring during free or assisted dives.