JOINT SERVICE SUB AQUA DIVING
DIVING
ILLNESS’ & TREATMENT
REVIEW
Diving Illness’
& Treatment
Review
Objectives
Revise Basic Life Support (BLS) skills
For diving incidents:
• understand the conditions
• recognise signs and symptoms
• understand how oxygen administration benefits these conditions
Understand appropriate equipment and the
practicalities of its use
Revise oxygen administration skills
• breathing casualties
• non-breathing casualties
2
06/2011
Diving Illness’
& Treatment
Review
Outline
BLS
In-Water Rescue
Medical conditions
Casualty Assessment
Oxygen administration equipment
Oxygen administration in practice
3
06/2011
Diving Illness’
& Treatment
Review
4
06/2011
BASIC LIFE SUPPORT (BLS)
Diving Illness’
& Treatment
Review
Lesson Outline
BLS skills:
• Essential rescue skills
• Deteriorate quickly if not
frequently exercised
• Advice/techniques evolve
Basis on which to build
oxygen-enriched RB:
• Will inevitably be needed while
equipment is readied
• Will form basis of oxygenenriched basic life support
DT2.6
08/02
Diving Illness’
& Treatment
Review
Assessing the Need
Indicators of the need for BLS:
• no response
• no chest movement
• no feel of air movement
7
06/2011
Diving Illness’
& Treatment
Review
Assessing the Need
Indicators of the need for BLS:
No response
No chest movement
No feel of air movement
DT2.8
08/02
Diving Illness’
& Treatment
Review
Priorities
D r A
B C
Danger – to casualty and rescuer
Response (AVPU)
Airway
Breathing
Compressions
9
06/2011
Diving Illness’
& Treatment
Review
Clear Airway
Foreign objects
Tongue
Airway blocked by
tongue
10
06/2011
Head tilt/chin lift
clears airway
Diving Illness’
& Treatment
Review
Priorities
Danger – to casualty and rescuer
Response
•
•
•
•
A – Alert
V – Responds to Voice
P – Responds to Pain
U – Unresponsive
Airway – clear of obstructions
Breathing – check for normal breathing (10 secs.)
Compressions – Cardiac Compressions
11
06/2011
Diving Illness’
& Treatment
Review
BLS: Decision Process
Unresponsive
Leave casualty and get help
No
Yes
Shout for help,
open up airway
Breathing normally?
No
Leave casualty and get help,
return & give 30CCs
Yes
Recovery position
Stop to recheck only if breathing resumes, else
continue until:
• Qualified help arrives
• Normal breathing
• You are exhausted
12
06/2011
Diving Illness’
& Treatment
Review
Basic Life Support
• Sequence of
30 compressions: 2 breaths by
one rescuer
• Two rescuers: change role
every 1-2 minutes
• Monitor effectiveness
• Stop if normal breathing
resumes/medical assistance
arrives
13
06/2011
Diving Illness’
& Treatment
Review
Basic Life Support - CC
Place heel of hand in centre
of chest
Place heel of other hand on
top of first hand
Straight arms – press down
on sternum 5-6 cm
Repeat at 100-120 times/min
14
06/2011
Diving Illness’
& Treatment
Review
Basic Life Support - RB
Expired air can sustain life
Monitor effectiveness
•
•
•
•
Sight
Feel
Sound
Appearance
Continue until qualified help
comes, the casualty is breathing
normally or you are exhausted
15
06/2011
Don’t over
ventilate
Diving Illness’
& Treatment
Review
Basic Life Support - RB
Breaths are to be
• No more than 1 second each
• 2 breaths to take no more than 5 seconds
• Don’t attempt more than 2 breaths each cycle
Regurgitation
• Not always normal vomiting
• Monitor exhalation sounds
16
06/2011
Don’t over
ventilate
Diving Illness’
& Treatment
Review
Recovery Position
If casualty breathing place in recovery position
The ‘how’ position
17
06/2011
More stable position
Diving Illness’
& Treatment
Review
18
06/2011
IN-WATER RESCUE
Diving Illness’
& Treatment
Review
In Water Life Support Sequence
Make Buoyant
Extend Airway
RB for 1 minute
Tow, RB - 2 every 15 secs.
Standing depth/Boat 1 min. RB
De-Kit & Land
20
06/2011
Diving Illness’
& Treatment
Review
Rescue - to the surface
Diver out of gas
• AS Ascent
Incapable/unconscious diver
• CBL
Rescue ascents - Urgent
• Ascend directly to surface
• May mean ignoring decompression
stops
• Divers safer at surface
• DCI can be treated
• Actions to take in case of oxygen
convulsions
21
06/2011
AS ascent
Controlled
Buoyant Lift
Diving Illness’
& Treatment
Review
Surface Tows to Shore
Summon help
• Ensure casualty buoyant at surface
• Fully inflate BC - face clear of water
Consider removing weights
• Summon assistance
Conscious casualty
• Reassure
• Unconscious casualty
• Remove mask, mouthpiece and extend
airway
Non Breathing casualty
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06/2011
• Remove mask, mouthpiece and give RB for 1
minute i.e. 10RBs
Diving Illness’
& Treatment
Review
Landing Casualty - Shore
Standing depth
• Continue RB for a further 1 minute
• De-kit and land as quickly as possible
WITHOUT further rescue breathing
Lift from water
• Contact emergency services
• Continue BLS
23
06/2011
Diving Illness’
& Treatment
Review
Landing Casualty - Boat
Assistance available
• At boat prior to landing Continue RB for a further 1 minute
• De-Kit and remove from water as quickly as possible WITHOUT
further RB
• Contact emergency services
• Continue BLS
24
06/2011
Diving Illness’
& Treatment
Review
Effective Rescues
Typical indications
•
•
•
•
Nervous or reluctant
Excuses or repeated questions
Stress indicators
Slow kit up or constant fiddling
Concerns need to be
resolved
• Adapt the dive plan
• More suitable dive site
• Peer pressure
25
06/2011
Diving Illness’
& Treatment
Review
Pre-Dive Buddy Awareness
Buddy reactions
•
•
•
•
•
Stopping for no reason
Preoccupation with kit
Slow response to signals
Rapid breathing
Wide staring eyes
Resolve quickly
•
•
•
•
26
06/2011
Stop or move to buddy
OK? Problem?
Not OK, gentle but firm contact
Abort dive
Diving Illness’
& Treatment
Review
27
06/2011
MEDICAL CONDITIONS
Diving Illness’
& Treatment
Review
Oxygen Exposure
Oxygen Partial Pressure Scale (bar)
Hypoxic
Abilities
impaired
.08 .10
Unconsciousness
.16
Long term toxicity risk
.21
.5
1.0
AIR
Hyperoxic
1.4 1.6
Short term
toxicity risk
At high concentrations oxygen is toxic
PO2<0.16 bar does not support life
Need to remain within accepted oxygen exposure
limits
29
06/2011
Diving Illness’
& Treatment
Review
Hypoxia
Abilities impaired
Hypoxic
.08 .10
Unconsciousness
What is it:
• Lack of oxygen
• PO2< 0.16 bar
30
06/2011
.16
.21
AIR
Diving Illness’
& Treatment
Review
Hypoxia
Abilities impaired
Hypoxic
.08 .10
Unconsciousness
.16
.21
AIR
Symptoms:
•
•
•
•
•
31
06/2011
Inability to think clearly, confusion, sense of losing it
Loss of co-ordination
Unconsciousness, death
Primary danger is symptoms may be vague or absent
It can occur suddenly and without warning!
Diving Illness’
& Treatment
Review
Hyperoxic
Long term toxicity risk
Hyperoxic
.21
AIR
.5
1.0
1.4 1.6
Short term
toxicity risk
What is it:
• Too much oxygen
• Oxygen becomes toxic at elevated partial pressures
There are two different effects of Hyperoxia:
• Whole Body Oxygen Toxicity when PO2>0.5 bar for long periods
• Central Nervous System (CNS) toxicity when PO2>1.4 bar for
even short periods
32
06/2011
Diving Illness’
& Treatment
Review
Whole Body Toxicity
Cause: long exposures to PO2>0.5 bar
Monitored to allow for recompression treatment
Physiological reactions including:
• Inflammation in the lungs
• Reduction in vital capacity
• Congestion, oedema, bronchitis, swelling of alveolar walls,
thickening of pulmonary arteries
• Visual impairment
Symptoms:
• Dry cough, discomfort in breathing cycle, increased breathing
resistance, shortness of breath,
• Severe pain, sub-sternal pain or burning
• Temporary short sightedness (Hyperoxic Myopia)
33
06/2011
Diving Illness’
& Treatment
Review
CNS Toxicity
Also known as Acute Oxygen Toxicity
Reaction to PO2 generally > 1.4 bar
Symptoms:
CON
V
E
N
T
I
D
- Convulsions
- Vision
- Ears, hearing disturbances
- Nausea
- Twitching
- Irritability
- Dizziness
Until convulsions begin, minor symptoms:
34
06/2011
• Can occur in ANY order or combination
• Increase in severity
Diving Illness’
& Treatment
Review
CNS Toxicity
Convulsions
• Tonic phase – do not assist
• Muscles become tense
• Casualty becomes rigid and holds breath
• Clonic phase – do not assist
• May occur seconds or minutes after the tonic
phase
• Casualty jerks violently (convulsion)
• Depressive phase - assist
• Casualty relaxes and is unconscious
• Potential loss of mouthpiece
• Loop flood – loss of buoyancy
• Need for Basic Life Support?
35
06/2011
Diving Illness’
& Treatment
Review
CNS Toxicity
Convulsions
• Phases can occur on surface or after PO2 is
reduced (‘Off effect’)
• Progressive damage to nervous system with
each successive convulsion
36
06/2011
Diving Illness’
& Treatment
Review
Hyperoxia
Long term toxicity risk
Hyperoxic
.21
AIR
.5
1.0
1.4 1.6
Short term
toxicity risk
Causes:
• Inaccurate dive planning
• Failure to analyse gas
• Incorrect marking or fitting of cylinders
37
06/2011
Diving Illness’
& Treatment
Review
Hyperoxia
Long term toxicity risk
Hyperoxic
.21
.5
1.0
AIR
Aggravating factors:
•
•
•
•
38
06/2011
Actual PO2
Duration of exposure
Level of exertion
Cumulative O2 exposure
1.4 1.6
Short term
toxicity risk
Diving Illness’
& Treatment
Review
Hyperoxia
Long term toxicity risk
Hyperoxic
.21
AIR
.5
1.0
1.4 1.6
Short term
toxicity risk
Avoidance:
• High PCO2 predisposes to oxygen toxicity
• Accurately track your oxygen exposure
39
06/2011
Diving Illness’
& Treatment
Review
Monitoring Oxygen Exposure
CNS and Whole Body Toxicity need
to be monitored separately
• Data for both provided in BSAC Oxygen
Toxicity Table
• Dive planning software
• Nitrox & mixed gas
decompression computers
40
06/2011
Diving Illness’
& Treatment
Review
Hypercapnia
What is it:
• Excess CO2 in the blood
Cause:
• High inspired PCO2
• Poor ventilation of diver’s lungs at depth
due to increased gas density
• Absorbent material exhausted in
rebreathers
• Channelling in absorbent material
rebreathers
41
06/2011
CO2
Diving Illness’
& Treatment
Review
Hypercapnia
Symptoms
42
06/2011
• 0.03 bar PCO2
doubles breathing rate
(dyspnea)
• 0.06 bar PCO2
distress, confusion, lack of
coordination
• 0.10 bar PCO2
severe mental impairment
• 0.12 bar PCO2
loss of consciousness,
death
CO2
Diving Illness’
& Treatment
Review
Hypercapnia
Further impact
• Increases oxygen toxicity potential
• Increases potential for DCI and narcosis
Avoidance
• Meticulous preparation & monitoring of
absorbent life - rebreathers
• Avoiding over exertion
Resolution
• Stop, slow down breathing rate, relax
• Bail out to open circuit - rebreathers
43
06/2011
CO2
Diving Illness’
& Treatment
Review
Decompression illness
Causes
• inadequate elimination of nitrogen from the body during ascent
• Physical damage to the alveoli due to overpressure introduces
bubbles of air (emboli) into the blood
Bubbles blocking
blood flow
Bubbles in tissues
compress blood
vessels
• Patent foramen ovale (PFO) allows bubbles to pass from venous
to arterial circulation
44
06/2011
Diving Illness’
& Treatment
Review
Decompression illness
Signs and symptoms
•
•
•
•
•
•
Denial!
Itches, rashes
Numbness, tingling, joint pains
Vision disturbances
Dizziness, nausea, headaches, confusion
Weakness, paralysis, loss of bladder/bowel
control
• Shortness of breath
• Shock, unconsciousness
• Any abnormality after a dive
45
06/2011
Signs and symptoms appear from
seconds to many hours after surfacing
Diving Illness’
& Treatment
Review
Decompression illness
On-site first aid
46
06/2011
• Lie casualty down flat
• Keep casualty quiet
• Administer 100% oxygen
• Increased nitrogen pressure gradient
assists in nitrogen elimination from
bubbles in blood and tissue
• The higher the percentage of oxygen the
more effective – whenever possible administer 100%
• Improved oxygen supply to tissues where blood flow is
reduced due to bubble blockage
• Treat for shock
• Evacuate to a recompression facility as soon
as possible
Diving Illness’
& Treatment
Review
Burst Lung
Cause
• Physical damage to lung tissue from over-extension due to
over-pressurisation
Types
Bubbles between
organs and tissues
(emphysema)
Collapsed lung
(pneumothorax)
Both types can occur in isolation but are usually
accompanied by air embolism
47
06/2011
Diving Illness’
& Treatment
Review
Burst Lung
Signs and symptoms
•
•
•
•
•
chest discomfort/pain, bloody froth
shortness of breath
changes to vocal tone, crepitation
shock
unconsciousness, death
Signs and symptoms of burst lung are frequently
accompanied by those for decompression illness
48
06/2011
Diving Illness’
& Treatment
Review
Burst Lung
On-site first aid
• Lie casualty down
• Keep casualty quiet
• Administer 100% oxygen
• Assists in re-absorption of the
nitrogen content of air in
pneumothorax or emphysema
• Offsets reduced effective lung
surface area for gas transfer
due to collapsed lung
• Treat for shock
• Evacuate to a recompression facility as soon as possible
49
06/2011
Diving Illness’
& Treatment
Review
Near Drowning
Cause
• Respiratory interruption due to fluid inhalation
Signs and symptoms
•
•
•
•
50
06/2011
Circumstances
No breathing
Cyanosis – ashen grey / blue appearance
Weak or absent pulse
Diving Illness’
& Treatment
Review
Near Drowning
On-site first aid
• Rescue Breathing
• Oxygen-enriched if possible
• Concentration of oxygen reaching the
casualty’s lungs during RBs is
increased
• Chest compressions if required
• Recovery position
• Evacuate to medical attention
• Even if apparently fully recovered
• Complications of secondary drowning
51
06/2011
Diving Illness’
& Treatment
Review
Shock
Definition
• inadequate circulation leading to tissue damage due to
inadequate oxygenation and waste removal
Present to a greater or lesser degree in all injuries
Mechanisms
•
•
•
•
•
52
06/2011
reduced blood volume (bleeding, burns, oedema)
massive dilation of blood vessels (e.g. fainting)
inadequate cardiac output (e.g. heart attack)
allergic reaction to drugs, food or stings
removal from the water after prolonged immersion
Diving Illness’
& Treatment
Review
Shock
Signs and symptoms
•
•
•
•
•
53
06/2011
weakness, dizziness
pallor, sweating
rapid pulse rate
rapid breathing, feeling breathless
unconsciousness
Diving Illness’
& Treatment
Review
Shock
On-site first aid
•
•
•
•
•
•
54
06/2011
•
•
•
Treat prime cause
Reassure casualty (TLC)
Keep casualty quiet
Lay casualty down with legs raised
(not in the case of DCI or burst lung)
Keep warm and comfortable
Administer oxygen
• Increased oxygen dissolved in the blood offsets effects of
inadequate circulation
Monitor condition
Nothing by mouth (except for DCI)
Evacuate to medical attention
Diving Illness’
& Treatment
Review
Shock
Immersion shock
• Extreme form of blood vessel
dilation due to prolonged
immersion
• Muscles relax due to water
supporting body weight
• If removed from water upright, blood
can pool in lower limbs – potentially
fatal
• Keep casualty horizontal at all times
• Discourage any movement or activity by the casualty
55
06/2011
Diving Illness’
& Treatment
Review
Carbon Monoxide Poisoning
Cause
• breathing gas contaminated with carbon
monoxide
Effect
• carbon monoxide combines about 200 times more
readily with haemoglobin than does oxygen
• interferes with the blood's ability to transport
oxygen
• may act as a cellular poison
56
06/2011
Diving Illness’
& Treatment
Review
Carbon Monoxide Poisoning
Signs and symptoms
•
•
•
•
•
•
•
•
•
•
57
06/2011
headache
pale or greyish appearance
weakness
dizziness, nausea
tunnel vision
vomiting
rapid pulse
rapid breathing
coma
convulsions
Diving Illness’
& Treatment
Review
58
06/2011
CASUALTY ASSESSMENT
Diving Illness’
& Treatment
Review
60
06/2011
Incident Procedure - Front
Diving Illness’
& Treatment
Review
61
06/2011
Incident Procedure - Back
Diving Illness’
& Treatment
Review
62
06/2011
Oxygen Administration Equipment
DT5.63
08/02
Diving Illness’
& Treatment
Review
Gas Cylinders
‘D’ size most convenient
370 to 540 litres (136 to 210 bar)
Larger cylinders available but often more
convenient to carry more smaller ones
Colour coding – (BS EN 1089-3)
• White shoulder
• Body any non-allocated colour but usually black
Pillar valve connections (BS EN 850)
• Two pin index holes
• Female outlet, no ‘O’ ring
DT5.64
12/2008
Diving Illness’
& Treatment
Review
Regulators
Outlet pressure
• Approximately 4 bar (some higher)
• Constant outlet pressure
Inlet
• Two index pins
• Male inlet with sealing washer
Simple pressure gauge
Outlets capable of supporting:
• At least one demand valve (100 to
160 litres / min. flow rate)
• 10 litres/min. (minimum) constant
flow
DT5.65
12/2008
Diving Illness’
& Treatment
Review
Demand Valves
Provide oxygen on demand
Can be capable of flow rates of
up to 160 litres / min.
Fitted with oro-nasal mask
• Transparent material
• Inflated or double face seal
• Large/adult and small/child sizes
DT5.66
12/2008
Diving Illness’
& Treatment
Review
Demand / Resuscitation
Valves
Available types
• Automatic
• Manually controlled
Configuration suitable for sport
diver use:
• Manually controlled
• 100 – 160 litres min. flowrate on
demand
• Resuscitation control limited to a
maximum flow rate of 40 litres /min
• Over pressure relief valves (set to a
pressure of approx 45cm of water)
DT5.67
12/2008
Diving Illness’
& Treatment
Review
‘Pocket’ Masks
Central ventilation orifice
May be fitted with a porous splash guard
May be supplied with an optional nonreturn / exhalation valve
Transparent material
Generally have inflated face seal
Connection (with non-return valve)
for constant flow oxygen tubing
DT5.68
12/2008
Diving Illness’
& Treatment
Review
Reservoir mask
aka Hudson/non-rebreathing
For second DCI casualty
Gives oxygen concentration
• Higher than pocket mask
• Not as high as demand mask
Parts
•
•
•
•
Oxygen tubing
Reservoir
Mask
Exhaust valves
Flow 10-15 l/min
Fill bag before use
DT5.69
12/2008
Diving Illness’
& Treatment
Review
Storage Cases
Storage cases should be:
• Robust
• Waterproof
• Ideally store equipment in fully
assembled state
• Case must have a pressure
release valve if used to store
cylinder
DT5.70
12/2008
Diving Illness’
& Treatment
Review
Precautions in Use
Fire risk - absolute cleanliness
a necessity
Keep equipment regularly
maintained
Do-it-yourself equipment or
modifications are dangerous
Do not use non-standard
equipment – risk of confusion
DT5.71
12/2008
Diving Illness’
& Treatment
Review
DT5.72
12/2008
OXYGEN ADMINISTRATION
IN PRACTICE
Diving Illness’
& Treatment
Review
Casualties
Incident statistics show that the majority of casualties
will be
• Breathing
• Conscious
• Suffering from decompression
illness
Will need the use of a demand
valve and oro-nasal mask for
maximum oxygen concentration
Incidence of casualties requiring
Rescue Breaths is much lower
74
06/2011
Diving Illness’
& Treatment
Review
Posture
For decompression illness or
burst lung, lay casualty flat
on back
If decompression illness or
burst lung is not involved
• Legs may be raised to counter
shock
• Monitor for signs of adverse
impact on casualty’s breathing
DT6.75
08/02
Diving Illness’
& Treatment
Review
Administering Oxygen
Start at the earliest opportunity
• Greater nitrogen pressure gradient
• Earliest reduction in tissue hypoxia
Don’t ration oxygen
Tender loving care (TLC)
For a second casualty
• Use second demand valve and
oro-nasal mask, if available
• Otherwise use a pocket mask
• Accept faster consumption of oxygen
76
06/2011
Diving Illness’
& Treatment
Review
Administering Oxygen
Be prepared for a possible transient worsening of
casualty’s condition
• Initial reaction of brain to increased
oxygen
• Oxygen diffusing into bubbles
Oxygen toxicity
• Not a problem at surface pressure /
durations involved
• Casualties of underwater O2 toxicity? –
administer O2 on surface once any signs or symptoms have
disappeared
No pain killers
77
06/2011
Diving Illness’
& Treatment
Review
Administering Fluids
Counter dehydration with fluids
• Still isotonic drinks best, or water/squash
• Do not administer caffeinated or fizzy drinks
• Small amounts, at a rate of approx 1 litre/hour
Do not allow to interfere with or delay
• Administration of oxygen
• Evacuation to a recompression facility
Do not administer fluids if
• Casualty is likely to vomit
• Casualty is likely to inhale fluid
• A general anaesthetic may be required
If no oxygen, fluids alone are beneficial
78
06/2011
Diving Illness’
& Treatment
Review
Evacuation
Don’t delay call to emergency services
Coastguard: VHF Channel 16
DDMO / BHA DCI Helplines:
• England, Wales & N. Ireland: 07827 821980
• Scotland: 0845 408 6007
On Land (other)
• Ambulance/Police/Coastguard
• Telephone: 999 or 112
DCI
79
06/2011
• Irrespective of any apparent improvement, casualty must get
medical attention
• Casualty’s buddy?
• All relevant information must accompany any casualty
Diving Illness’
& Treatment
Review
Oxygen Supply Exhausted?
Closed Circuit Rebreather
• Can be set to deliver 100% oxygen
Nitrox
• Open Circuit or Semi Closed Circuit
Rebreather
• Reduces the amount of inspired
nitrogen
• Not as effective as 100% oxygen
but better than breathing air
Common Considerations
• Mouthpiece may not be tolerated
• Oxygen % reduced by air inspired via nose
80
06/2011
Diving Illness’
& Treatment
Review
Missed Decompression
If a diver misses decompression stops for any reason,
or is subject to a rapid ascent such that it is
considered that they may suffer decompression illness
as a result…
•
•
•
•
81
06/2011
Do not wait for signs/symptoms to appear
Lay casualty down and keep quiet
Administer oxygen/fluids
Seek specialist medical advice on further action from the DDMO/
BHA Help lines
Diving Illness’
& Treatment
Review
Entonox
Mixture of oxygen and nitrous oxide
Nitrous oxide is very soluble in blood
• Large quantity of nitrous oxide passes into
nitrogen bubbles to re-establish equilibrium
• Causes size of bubbles to increase
Never administer to a casualty suffering
from a diving accident
Do not administer to a casualty of a
non-diving accident if this follows diving
Ensure emergency personnel fully
understand - Do this tactfully!
82
06/2011
Diving Illness’
& Treatment
Review
Summary
Administration of oxygen is beneficial to
the major diving disorders
100% oxygen will provide the maximum
benefit
Administer oxygen as early as possible
Oxygen is a supplement to other first aid
procedures to increase their effectiveness
Casualty must always be evacuated to
appropriate medical aid:
• As soon as possible
• Irrespective of any apparent resolution of
their condition
DT3.83
08/02
Diving Illness’
& Treatment
Review
Final Summary
Signs & symptoms can be similar for different
conditions
Knowledge of pre-incident history
helps
Oxygen administration & TLC
are beneficial to all diving
illnesses & incidents
84
06/2011
Diving Illness’
& Treatment
Review
85
06/2011