- List eight of the more commonly occurring signs or symptoms of decompression illness
SKIN: rash, marbling effect, red weals and itchiness
MUSCULOSKELETAL: Pain (esp. in joints), dull ‘ache’, numbness and tingling
NEUROLOGICAL: Loss of coordination, partial paralysis, confusion, convulsions, blurred vision
VESTIBULAR: Vertigo, nausea, vomiting
GASTROINTESTINAL: Nausea, abdominal cramps, vomiting, diarrhoea
CARDIO-
RESPIRATORY: Irregular heartbeat, shortness of breath, chest pain, coughing
- List four reasons why you would not recompress a victim of decompression illness in the water
Recompression takes a long time, so lack of adequate air supply
Cold
Dark
Inability to administer O2 at depth
If not on O2 then diver still on-gassing while underwater
Need for another diver to act as attendant (then they are also at risk)
Weather issues
Dangerous marine animal risks
- Describe the appropriate first aid for a suspected victim of decompression illness.
Give at least six points.
DRABCD
Lay diver flat if conscious or in left lateral position if unconscious
Administer 100% O2
Treat for shock: Reassure, make thermally comfortable
Activate emergency
procedures: Call DES / Hyperbaric Unit / Ambulance
Record all relevant details: Dive history, predisposing factors, treatment etc
- Why is oxygen, rather than air, usually used for the treatment of decompression illness
in a recompression chamber?
Produces maximum diffusion gradient to reduce bubble size/eliminate N2 from tissues as quickly as possible
Doesn’t allow more N2 to on-gas into patient
Helps re-oxygenate hypoxic tissues
- Apart from bounce diving and diver obesity, list six other factors that may predispose a diver to decompression illness.
Elevated CO2 levels
Dehydration
Deep dives
Long dive times
Repetitive dives
Multi-day diving
Poor dive profiles
Multiple ascents
Rapid ascents
Alcohol
Medications or other drugs
Age
Fatigue
Illness
Physical injury or previous DCI
Anxiety
PFO
Cold diver
Road travel to altitude after diving
Flying after diving
Lack of fitness
Exercise after dive
Exercise during dive
Diving at altitude
Nitrogen narcosis
What is dysbaric osteonecrosis and how is it caused?
death of bone tissue - no oxygen to bone tissue
bubbles from untreated DCI blocking blood supply in bones
how is dysbaric osteonecrosis detected?
xray
how is dysbaric osteonecrosis avoided?
Correct use of deco tables; conservative diving practices, avoiding deep or repetitive dives. Early recognition of DCI, and appropriate treatment.
whats the difference between dci and and decompression sickness?
illness - broader term encompasses DCI and AGES
DCS - symptoms that arise from gas bubbles forming in the tissues themselves
what first aid is given for DCI?
100% o2, decomp chamber if available, provide psych support, keep warm, DRABCD if needed,
what does aspirin do in relation to DCI?
reduces blood clots and aggregation of platelets, which contributes to gas bubble formation - platelets attach to bubbles to form clotting
what is the term silent bubbles mean?
gas bubbles forming with no signs of symptoms (benign)
what is an ultrasonic doppler flowmeter?
device used to measure blood flow rate by ultrasonic sound wave mechanism
what could unresolved bubbles do in body?
chronic pain
cognitive defects
paralysis / death
what is dysbaric osteonosis?
the death of bone tissue due to prolonged gas bubbles in bone marrow
multiple ascents / yoyo diving does what in relation to DCI?
no clear timeframe to blow off nitrogen / offgas. steady increase of nitrogen over time.
high levels of co2 do what to the the body?
cause vasoconstriction = reduces tissues ability to off gas N therefore increasing DCI and DCS
common symptoms of DCI
joint pain
numb left arm
skin rash - red
fatigue
max pressure of o2 normally used for treatment of DCI?
2.8 ATM
list 3 benefits of using 100% o2 in recompression chambers?
no additional nitrogen to body
offgassing N more rapidly
oxygenation to body where it was restricted during dive
minimum SI using DCIEM tables?
allowable decent / ascent rate?
18 +/- 3 m per min
define AGES?
Arterial Gas Embolism syndrome
