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Joint Service Sub Aqua Diving Centre
DIVING DIVING
ILLNESS’ & TREATMENTILLNESS’ & TREATMENT
REVIEWREVIEW
DIVING DIVING
ILLNESS’ & TREATMENTILLNESS’ & TREATMENT
REVIEWREVIEW
Diving Illness and Treatment
Review
Diving Illness and 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
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Outline
BLS
Medical conditions
Casualty Assessment
Oxygen administration equipment
Oxygen administration in practice
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Lesson Outline
BLS skills:• Essential rescue skills
• Deteriorate quickly if not frequently exercised
• Advice/techniques evolve
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Assessing the Need
Indicators of the need for BLS:
• no response• no chest movement• no feel of air movement
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Priorities
D r A B CDanger – to casualty and rescuer
Response (AVPU)
Airway
Breathing
Circulation
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Clear airway
Foreign objects
Tongue
Airway blocked by tongue
Head tilt/chin lift clears airway
Diving Illness and Treatment
Review
Diving Illness and 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.)
Circulation – Cardiac Compressions
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review BLS: Decision Process
Unresponsive
Recovery position
Leave casualty and get help
Shout for help, open up airway
Breathing normally? Leave casualty and get help, return and give 30CCs
No
No
Yes
YesStop to recheck only if breathing resumes, else continue until:•Qualified help arrives•Normal breathing•You are exhausted
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Basic Life Support (BLS)
Monitor effectiveness:• Sequence:
30 compressions : 2 breaths• Rate of 100 compressions/minute• 4–5cm compression
• Stop if normal breathing resumes/medical assistance arrives
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Rescue breaths (RB)
Monitor effectiveness:
Don’t over ventilate
• Sight• Feel• Sound• Appearance
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Oxygen Exposure
At high concentrations oxygen is toxic
PO2<0.16 bar does not support life
Need to remain within accepted oxygen exposure limits
Hyperoxic
Oxygen Partial Pressure Scale (bar)
1.0.5.21 1.6.16.10.08 1.4
Short term toxicity risk
Long term toxicity riskHypoxic
Unconsciousness
Abilities impaired
AIR
1.3.7
Inspiration default set points
Low High
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Hypoxia
What is it:• Lack of oxygen • PO2< 0.16 bar
.21.16.10.08
Hypoxic
Unconsciousness
Abilities impaired
AIR
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Hypoxia
Symptoms:• 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!
.21.16.10.08
Hypoxic
Unconsciousness
Abilities impaired
AIR
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Hyperoxia
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
Hyperoxic
1.0.5.21 1.61.4
Short term toxicity risk
Long term toxicity risk
AIR
Diving Illness and Treatment
Review
Diving Illness and Treatment
ReviewWhole 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)
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review CNS Toxicity
Also known as Acute Oxygen Toxicity
Reaction to PO2 generally > 1.4 bar
Symptoms:
CON - Convulsions
V - Vision
E - Ears, hearing disturbances
N - Nausea
T - Twitching
I - Irritability
D - Dizziness
Until convulsions begin, minor symptoms:• Can occur in ANY order or combination
• Increase in severity
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review CNS Toxicity
Convulsions• Tonic phase – do not assisto Muscles become tense
o Casualty becomes rigid and holds breath
• Clonic phase – do not assisto May occur seconds or minutes after the tonic phaseo Casualty jerks violently (convulsion)
• Depressive phase - assisto Casualty relaxes and is unconsciouso Potential loss of mouthpiece
– Loop flood – loss of buoyancy– Need for Basic Life Support?
Diving Illness and Treatment
Review
Diving Illness and 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
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Hyperoxia
Causes:• Inaccurate dive planning
• Failure to analyse gas
• Incorrect marking or fitting of cylinders
Hyperoxic
1.0.5.21 1.61.4
Short term toxicity risk
Long term toxicity risk
AIR
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Hyperoxia
Aggravating factors• Actual PO2
• Duration of exposure
• Level of exertion
• Cumulative O2 exposure
Hyperoxic
1.0.5.21 1.61.4
Short term toxicity risk
Long term toxicity risk
AIR
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Hyperoxia
Avoidance:• High PCO2 predisposes to oxygen toxicity
• Accurately track your oxygen exposure
Hyperoxic
1.0.5.21 1.61.4
Short term toxicity risk
Long term toxicity risk
AIR
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Monitoring Oxygen Exposure
CNS and Whole Body Toxicity need to be monitored separately• Data for both provided in BSAC Oxygen
Toxicity Table
• Nitrox & mixed gas decompression computers
• Dive planning software
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Hypercapnia
What is it:• Excess CO2 in the blood
Cause:• High inspired PCO2
o Poor ventilation of diver’s lungs at depth due to increased gas density
o Absorbent material exhausted in rebreathers o Channelling in absorbent material rebrerathers
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Hypercapnia
Symptoms• 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
Diving Illness and Treatment
Review
Diving Illness and 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
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review
Bubbles blocking blood flow
Bubbles in tissues compress blood vessels
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
Decompression illness (1)
Patent foramen ovale (PFO) allows bubbles to pass from venous to arterial circulation
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Decompression Illness (2)
• Denial!
• Itches, rashes
Signs and symptoms
• Vision disturbances
• Dizziness, nausea, headaches, confusion
• Weakness, paralysis, loss of bladder/bowel control
• Shortness of breath
• Shock, unconsciousness
• Any abnormality after a dive
Signs and symptoms appear from seconds to many hours after surfacing
• Numbness, tingling, joint pains
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Decompression Illness (3)
• Lie casualty down flat
• Keep casualty quiet
• Administer 100% oxygeno Increased nitrogen pressure gradient assists in
nitrogen elimination from bubbles in blood and tissue
o The higher the percentage of oxygen the more effective – whenever possible administer 100%
o Improved oxygen supply to tissues where blood flow is reduced due to bubble blockage
• Treat for shock
On-site first aid
Evacuate to a recompression facility as soon as possible
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Burst lung (1)
Cause• physical damage to lung tissue from over-extension due
to over-pressurisation
Types
Collapsed lung(pneumothorax)
Bubbles between organs and tissues (emphysema)
• Both types can occur in isolation but are usually accompanied by air embolism
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Burst lung (2)
Signs and symptoms include• 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
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Burst Lung (3)
• Lie casualty down
• Keep casualty quiet
• Administer 100% oxygeno Assists in re-absorption of the nitrogen
content of air in pneumothorax or emphysemao 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
On-site first aid
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Near Drowning (1)
Cause• Respiratory interruption due to fluid inhalation
Signs and symptoms• Circumstances• No breathing• Cyanosis – ashen grey / blue appearance• Weak or absent pulse
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Near Drowning (2)
• Rescue Breathingo Oxygen-enriched if possibleo Concentration of oxygen reaching the
casualty’s lungs during RBs is increased
• Chest compressions if required
• Recovery position
• Evacuate to medical attentiono Even if apparently fully recoveredo Complications of secondary drowning
On-site first aid
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Shock (1)
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• 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 and Treatment
Review
Diving Illness and Treatment
Review Shock (2)
Signs and symptoms• weakness, dizziness
• pallor, sweating
• rapid pulse rate
• rapid breathing, feeling breathless
• unconsciousness
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Shock (3)
On-site first aid• 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 oxygeno 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 and Treatment
Review
Diving Illness and Treatment
Review Shock (4)
• 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
Immersion shock
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Carbon monoxide poisoning (1)
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
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Carbon monoxide poisoning (2)
Signs and symptoms• headache
• pale or greyish appearance
• weakness
• dizziness, nausea
• tunnel vision
• vomiting
• rapid pulse
• rapid breathing
• coma
• convulsions
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Carbon monoxide poisoning (3)
On-site first aid• remove casualty from contaminated breathing supply
• lie casualty down with legs raised
• administer 100% oxygen, or oxygen enriched Rescue Breaths, as appropriate
Benefits of 100% oxygen• more oxygen is transported in solution in the plasma
• some assistance in breaking down carboxyhaemoglobin
• helps restore normal cellular function
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Summary of diving illnesses
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
OXYGEN ADMINISTRATION OXYGEN ADMINISTRATION EQUIPMENTEQUIPMENT
OXYGEN ADMINISTRATION OXYGEN ADMINISTRATION EQUIPMENTEQUIPMENT
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Lesson Outline
Configuration of oxygen administration equipment most suitable for sport diver use
Oxygen administration equipment comprises• Gas cylinder Colour coding – (BS EN
1089-3)
• Regulator Pillar valve connections (BS EN 850)
two pin index, female outlet, no ‘O’ ring
• Demand valve and mask At least one demand valve (100 to 160 litres / min. flow rate), 10 litres/min. (minimum) constant flow
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Oxygen
Characteristics• A colourless, odourless, tasteless gas
• Comprises approximately 21% of the atmosphere (by volume)
• An essential component of metabolism
• Carried in the blood streamo Primary means - combined with the haemoglobin o Secondary means - dissolved in the blood plasma
• Plasma’s capacity to transport additional oxygen utilised in oxygen administration
Will not burn but supports the combustion of other materials
Diving Illness and Treatment
Review
Diving Illness and 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
OXYGEN ADMINISTRATION OXYGEN ADMINISTRATION IN PRACTICEIN PRACTICE
OXYGEN ADMINISTRATION OXYGEN ADMINISTRATION IN PRACTICEIN PRACTICE
Diving Illness and Treatment
Review
Diving Illness and 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
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Administering Oxygen (1)
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
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Administering Oxygen (2)
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
Diving Illness and Treatment
Review
Diving Illness and 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
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Evacuation
Don’t delay call to emergency services
Coastguard: VHF Channel 16
DDMO / BHA DCI Helplines:• England, Wales & N. Ireland: 07 831 151 523
• Scotland: 0845 408 6007
On Land (other)
Ambulance/Police/Coastguard• Telephone: 999 or 112
DCI• Irrespective of any apparent improvement, casualty must get medical
attention
• Casualty’s buddy?
All relevant information must accompany any casualty
Diving Illness and Treatment
Review
Diving Illness and 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
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Missed Decompression
• 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
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:
Diving Illness and Treatment
Review
Diving Illness and Treatment
Review Entonox
Do not administer to a casualty of a non-diving accident if this follows diving
Ensure emergency personnel fully understand
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 this tactfully!
Diving Illness and Treatment
Review
Diving Illness and Treatment
ReviewDDMO Contact
If you suspect a diver may have a diving related problem, even if just a headache after a dive:
• Call Defence Diving Medical Offr (DDMO)
• 24/7 manned number
• 07831151523
• 02392768020
Diving Illness and Treatment
Review
Diving Illness and Treatment
ReviewDiving illness & treatments
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