GUE - Fundamentals - Breathing Gas Dynamics Flashcards
Why is managing oxygen toxicity so challenging?
Because our susceptibility to oxygen varies from person to person and even from day to day.
What is the acronym we use to help remember the signs and symptoms of CNS oxygen toxicity?
CONVENTID
Convulsions Visual Disturbances Ear Disturbances Nausea Twitching Irritability Dizziness
What is the recreational limit of oxygen used by GUE recreational divers?
1.4ppO2
What is the leading cause of CNS oxygen toxicity in diving?
Breathing the wrong gas at the wrong depth.
What are effects of narcosis?
Impaired ability to make sound judgements.
Degradation of neuromuscular performance.
A sense of euphoria.
Can divers build up tolerance to the effects of narcosis?
No
What is the maximum Equivalent Narcotic Depth that we expose ourselves to as GUE divers?
30m
essentially 100 feet
What is the most narcotic gas we are likely to be exposed to when diving?
Carbon dioxide.
Why is avoiding dense breathing gas underwater important?
Dense gas mixtures make it harder for the body to move the gas into and out of the lungs, resulting in reduced gas transfer and CO2 removal.
What can we do to reduce gas density when diving?
Add helium to the breathing mix.
What is hypercapnia?
Excess carbon dioxide in the body causing carbon dioxide toxicity.
What are some of the symptoms of hypercapnia?
Rapid breathing.
Headache.
Panic.
What causes CO2 build up in the body?
Incorrect gas choice.
Excessive exertion.
Incorrect equipment selection.
What should a diver do in the case of CO2 toxicity?
Stop, stabilize and reduce exertion, signal the team. If symptoms persist then end the dive.
What are the advantages of GUE’s standard gases?
They provide an easy to remember, safe and efficient way to plan and execute dives, protecting the diver from the multitude of gas property issues associated with diving.
What is the additional measure taken to ensure the proper gas mixture is being breathed when diving?
Proper gas analysis of the breathing mix by the diver using it, conducted on the day of diving and correctly marked up.
Select the option that correctly lists the narcotic gasses, from that with the most narcotic potential to least narcotic potential.
Carbon dioxide.
Oxygen.
Nitrogen.
Helium.
Which of the following is an effect of breathing high density gases?
Increased CO2 levels.
Which of the following are signs or symptoms of CO2 toxicity (hypercapnia)?
Rapid breathing.
Panic.
Perceptual narrowing.
What is the recommended equivalent narcotic depth (END) recommended by GUE?
30m
100 feet
Which of the following is a symptom of CNS oxygen toxicity?
Convulsions.
What is the maximum recommended ppO2 for a recreational dive?
1.4ppO2
