cgier 31

Question 1

oxygen toxicity is caused when

Answer 1

-po2 is higehr than 1.6
- results in convulsions and fatal underwater
- 6m for pure o2
- 66m for air mix

Question 2

nitrogen necrosis is caused by

Answer 2

pn2 > 3.2 and has intoxicating effects at deeper than 25 m

Question 3

intoxicating effects of nitrogen is related to the

Answer 3

depth and can act as anaesthetic at greater depth.
Nacrosis is = 1 unit of alcohol for 10 meter of depth

Question 4

nitrogen necrosis can result in

Answer 4

• loss of motor function
• deterioration in decision making ability
• symptoms are relieved when u ascend slow

Question 5

holding ur breath in emergency ascend leads to

Answer 5

overexpansion of the lungs so use the blow and go method

Question 6

Boyles law injury

Answer 6

-overexpansion of the lungs
-bullous emphysema
Mediastinal emphysema ( leaking of air into the medial
- in descent, you can feel squeeze in the ear, relieve the pain by valsalva manoeuvre
- sinus squeeze can occur when u dive while u have a cold or URT
- mask squeeze can occur when the pressure in the face mask is not equalised. need to leak the air into the mask.
- diving w/ googles lead to black eyes

Question 7

shallow water blackout occur in

Answer 7

• breath holding divers
• snorkellers
• spear fishing
• free diving

Question 8

the urge to breathe is stimulated by

Answer 8

-elevated pc02.
- hyperventilating aka increase the rate and depth to maximise the 02 volume in the lungs so we start w partial pressure of 0.24 instead of 0.21 atm
- hyperventilating leafs to blowing off of the co2 so start the dive w/ abnormally low pc02

Question 9

loss of conscious occurs when the partial pressure of 02 is

Answer 9

drop below 0.1 atm

Question 10

hyberabric therapy ( HPOT)

Answer 10

• the use of higher ambient pressure to treat illnesses
• used for: radiation, tissue damage , clostridial myonecrosis aka the gas gangrene-anerobic infection, compromised skin grafts, crush injuries, problems w/ non healing wounds, acute carbon monoxide poisoning , decompression sickness, cynide poising.

Question 11

Gamow is the

Answer 11

portable hyperbaric chamber used to treat altitude sickness as:
High Altitude Pulmonary Edema (HAPE -fluid on the lungs) and High Altitude Cerebral Edema (HACE - fluid on the brain)

Question 12

the diver case lol

Answer 12

Diver had used air activated heat packs (iron oxidation) inside his plastic membrane dive suit to warm him during the dive but also used an compressed air to inflate his plastic membrane dry-suit. Auto-ignition of air-activated heat packs at high partial pressure of oxygen and high ambient pressure ignited his suit and undergarments. Subsequent rupture of suit at depth quenched fire.
( NAVY NO LONGER USES NYLON UNDERGARMENT FOR DIVERS )