DIVING INJURIES

Question 1

BAROTRAUMA OF DECENT

Answer 1

(boyles law)
Aka squeeze
- Compression of gas in enclosed space as ambient
pressure increases with descent under water
Mechanism:
- air trapping in noncollapsible chambers is compressed
- Leads to vacuum-type effect
- Distortion of anatomical structures
- Vascular engorgement
- Edema
- Hemorrhage of the exposed tissue
Results from:
- Blocked Eustachian tube
- Failure of the diver to clear (open) the Eustachian tube
- with exhalation during descent

Question 2

BAROTRAUMA OF ASCENT

Answer 2

(boyles law)
Aka reverse squeeze
- Air is not allowed to escape because of obstruction, the
expanding gasses distend the tissues surrounding them
Cause:
- Holding breath as you ascend
Complication – pulmonary overpressurization
- Expansion leads to alveolar rupture
- Leakage of air to surrounding structures in the body

Question 3

AIR EMBOLISM

Answer 3

(boyles law)
- Cause: ascend too rapidly or hold breath during ascent
- Expanding air disrupts tissues and air is forced into
circulatory system
- Should suspect if diver suddenly loses consciousness
immediately after surfacing

Question 4

DECOMPRESSION SICKNESS

Answer 4

(Henry’s law.)
Aka the bends, dysbarism, caisson disease, diver’s paralysis
- Nitrogen in compressed air converts back from solution
to gas
- Occurs when ambient pressure decreases – thus, too
rapid an ascent
- should be making regular stops during ascent
Most often affects joints and spinal cord
- In compressed gas nitrogen is dissolved into tissues and
blood from the increased partial pressure of the gas at
depth.
- This all leads to poor perfusion and ischemia.
- Symptoms are typically delayed 12-36 hrs after diving.

Question 5

NITROGEN NARCOSIS

Answer 5

(dalton’s law)
- Nitrogen becomes dissolved in blood
- Cause: higher than normal partial pressure of nitrogen
- Dissolved nitrogen then crosses the blood-brain barrier
and produces a depressant effect.

- at depths of 75-100ft. You will go unconscious at 300ft. 
  Like alcohol the more drinks you have the worse your 
  depressant symptoms are.    -  Common with all divers but better tolerated with 
  experienced divers