CGIER 30 -Barotrauma

Question 1

How does pressure change occur during diving?

Answer 1

deeper a swimmer goes the pressure increases for every 10m one person goes the ambient pressure increases by atm.

Question 2

Why can’t we use long tube instead of scuba diving

Answer 2

air at 1 atm pressure out of sea inflate lungs in the atmosphere of 2 atm. One won’t be able to overcome difference in pressure. Impossible to inflate

Question 3

SCUBA

Answer 3

Self
Contained
Underwater
Breathing 
Apparatus

Question 4

How does partial pressure affect the gas absorption to henry’s law

Answer 4

Gas (O2, N2) Solubility in tissues increases with gas partial pressure

Question 5

how will partial pressure of Oxygen and Nitrogen gas change when diving according to what law?

Answer 5

Will experience abnormally high pO2 and pN2 (Dalton’s Law).

Question 6

What causes decompression sickness. How do we prevent it?

Answer 6

Must ascend VERY SLOWLY.
Caused if one ascend too quickly or don’t give enough time for body to get rid of gas -
Boyles law - gas (Mostly Nitrogen) will expand as they get larger in size they can block blood vessels and can interrupt signals being passed if bubbles are in the nerves. Body won’t have enough time to expel the gas via respiration.

Question 7

solution for decompression sickness

Answer 7

quickly administer O2 and move to re-compression chamber

Question 8

how long can it take for some tissue to naturally expel the excess gas?

Answer 8

24 hours
Must NOT go to a plane within 24 hours - residual dissolved gas can form bubbles in parts of the body and you will be financially liable

Question 9

What do Commercial Divers use

Answer 9

dive greater than 60m - replace nitrogen w/ inert gas e.g. helium or argon.
Helium is light and will diffusing out of your body so quickly

Question 10

what was Decompression Sickness originally called

Answer 10

Caisson Disease

Question 11

First documented case of Decompression Sickness

Answer 11

pressurised container used to drive water out - people would work and dig in high pressure environment

Question 12

Where else is there a risk of Decompression Sickness

Answer 12

During spacewalks in astronauts

Suits work at one third of Atmospheric Pressure - must slowly decompress to 1/3 of atm

Question 13

Why not just replace all the N2 with oxygen while diving?

Answer 13

O2 becomes toxic for any pO2 greater than 1.6 atm. Results in convulsions, usually fatal underwater.

Question 14

Nitrogen Narcosis

Answer 14

seen in around of 25 m and higher

when partial pressure is greater than 3.2 atm - has intoxicating effect

Question 15

who are most susceptible to nitrogen narcosis

Answer 15

novice divers

Question 16

what does nitrogen narcosis cause

Answer 16

loss of motor function and deterioration in decision making ability

Question 17

Why should we NOT hold our breath as we head to the surface of the lung

Answer 17

lungs have not adapted to low pressure as you have not inhaled. Lungs will rupture - Boyle’s law

Question 18

Sinus squeeze

Answer 18

gas can move to sinuses and as they move to surface the gas expands

Question 19

Mask squeeze

Answer 19

when one forgets to equalise pressure in face mask
can result in two black eye
Disappears within a weak

Question 20

shallow water blackout happens to who

Answer 20

snorkellers
spear fishing
free diving

Question 21

shallow water blackout

Answer 21

limited supply of oxygen as one does not have oxygen tank - can hyperventilate using more oxygen and blowing off more pCO2. If pO2 drops below 0.1atm you can pass out

Question 22

Hyperbaric therapy

Answer 22

Use of higher than ambient pressures to treat a variety of illnesses

Question 23

hyperbaric therapy is used to treat

Answer 23

Radiation Tissue Damage (Soft Tissue and Osteoradio-necrosis)
Gas Gangrene-anaerobic infection)
Acute Carbon monoxide poisoning

Question 24

Gamow Bage

Answer 24

A portable hyperbaric chamber can be used to treat Altitude Sickness