NITROX EXAM GUIDE QUESTIONS WITH
CORRECT ANSWERS
nitrox mix - Answer-more than 21% O2 and less than 79% N2
--this course covers 22-40% O2
O2 and N2 - Answer-O2 is vital in metabolism, N2 is inert, but always absorbed during
dives
Nitrox benefits - Answer--extended no deco
-reduced surface intervals, more dives in a given time
-physiological advantage, when used with air tables or computer
nitrox downsides - Answer--some risks with elevated O2 exposures
-can be successfully managed with proper techniques
Nitrox history - Answer--references back to 1800
-published discussion of nitrox 1943
-navy introduced in 1959
-noaa launched nitrox program in 1970
....
Nitrox various names - Answer-enriched air nitrox
abbreviations EAN EANx EAN32
alternate names NOAA Nitrox I and II
denitrogenated air
oxygen enriched air
safe air
enriched air
determining the partial pressure of a gas - Answer-PG= P * FG
physiological effects of pressure - Answer-gas dynamics- gases move throughout the
body in response to partial pressure
Nitrogen dynamics - Answer--upon descent, press increases inside lungs, hence while
they move out into tissues
-upon ascent, pressure in tissues higher, and now the gradient is reversed, moves back
in lungs
deco sickness - Answer-tissues can tolerate some degree of super saturation
--limits are exceeded, gas can come out of solution and form bubbles
contributing factors -- dehydration, cold, rapid ascent, workload
, -tables and commuters help manage nitrogen exposures
nitrogen narcosis - Answer--elevated partial pressure of N2 can cause intoxicated like
conditions
-not harmful, just may cause you to make bad decisions
oxygen dynamics - Answer--tends to occur in a one direction because its used in
metabolism
-CO2 is is by product
**
CNS toxicity - Answer--body can tolerate some over oxygenation
-elevated pp of O2 can interfere with CNS function
-convulsions may be first and only symptom
-potentially fatal due to risk of losing reg and drowning
symptoms of CNS toxicity - Answer-ConVENTED - convulsions visual disturbances
euphoria nausea tinnitus irritability dizziness
contributing factors to CNS - Answer-elevated Co2 **
how to help someone with CNS toxicity - Answer-"if something seems wrong, it is
wrong"
-establish physical control
-start slow ascent
-if reg is in mouth, hold it there
-if reg is out, don't put it back
-seek medical attention
pulmonary o2 toxicity - Answer--dry, hacking, non productive coup
-can effect whole body "whole body toxicity"
-not a concern for sport divers
pulmonary barotrauma - Answer--cause when expanding air is not properly venter
-ex pneumothorax and medistinal emphysema subcutaneous emphysema arterial gas
embolisms
Haldanes deco model - Answer--study for the navy
-theoretical tissue compartments which correlate to their own half time
-max tissue pressure gradient upon ascent (m-value)
modern dive tables - Answer--used by a diver to manage N2 exposures
-use tables you're most comfortable with
-susceptibility to DCS can vary from diver to diver and conditions
features of diver tables - Answer-max bottom time
CORRECT ANSWERS
nitrox mix - Answer-more than 21% O2 and less than 79% N2
--this course covers 22-40% O2
O2 and N2 - Answer-O2 is vital in metabolism, N2 is inert, but always absorbed during
dives
Nitrox benefits - Answer--extended no deco
-reduced surface intervals, more dives in a given time
-physiological advantage, when used with air tables or computer
nitrox downsides - Answer--some risks with elevated O2 exposures
-can be successfully managed with proper techniques
Nitrox history - Answer--references back to 1800
-published discussion of nitrox 1943
-navy introduced in 1959
-noaa launched nitrox program in 1970
....
Nitrox various names - Answer-enriched air nitrox
abbreviations EAN EANx EAN32
alternate names NOAA Nitrox I and II
denitrogenated air
oxygen enriched air
safe air
enriched air
determining the partial pressure of a gas - Answer-PG= P * FG
physiological effects of pressure - Answer-gas dynamics- gases move throughout the
body in response to partial pressure
Nitrogen dynamics - Answer--upon descent, press increases inside lungs, hence while
they move out into tissues
-upon ascent, pressure in tissues higher, and now the gradient is reversed, moves back
in lungs
deco sickness - Answer-tissues can tolerate some degree of super saturation
--limits are exceeded, gas can come out of solution and form bubbles
contributing factors -- dehydration, cold, rapid ascent, workload
, -tables and commuters help manage nitrogen exposures
nitrogen narcosis - Answer--elevated partial pressure of N2 can cause intoxicated like
conditions
-not harmful, just may cause you to make bad decisions
oxygen dynamics - Answer--tends to occur in a one direction because its used in
metabolism
-CO2 is is by product
**
CNS toxicity - Answer--body can tolerate some over oxygenation
-elevated pp of O2 can interfere with CNS function
-convulsions may be first and only symptom
-potentially fatal due to risk of losing reg and drowning
symptoms of CNS toxicity - Answer-ConVENTED - convulsions visual disturbances
euphoria nausea tinnitus irritability dizziness
contributing factors to CNS - Answer-elevated Co2 **
how to help someone with CNS toxicity - Answer-"if something seems wrong, it is
wrong"
-establish physical control
-start slow ascent
-if reg is in mouth, hold it there
-if reg is out, don't put it back
-seek medical attention
pulmonary o2 toxicity - Answer--dry, hacking, non productive coup
-can effect whole body "whole body toxicity"
-not a concern for sport divers
pulmonary barotrauma - Answer--cause when expanding air is not properly venter
-ex pneumothorax and medistinal emphysema subcutaneous emphysema arterial gas
embolisms
Haldanes deco model - Answer--study for the navy
-theoretical tissue compartments which correlate to their own half time
-max tissue pressure gradient upon ascent (m-value)
modern dive tables - Answer--used by a diver to manage N2 exposures
-use tables you're most comfortable with
-susceptibility to DCS can vary from diver to diver and conditions
features of diver tables - Answer-max bottom time
