Joint Service Sub Aqua Diving Centre DIVING ILLNESS’ & TREATMENT REVIEWDIVING 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 Outline BLS Medical conditions Casualty Assessment Oxygen administration equipment Oxygen administration in practice

Basic Life Support (BLS) (BLS)

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 Assessing the Need Indicators of the need for BLS : no response no chest movement no feel of air movement

Diving Illness and Treatment Review Priorities D r A B C Danger – to casualty and rescuer Response (AVPU) Airway Breathing Circulation

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 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 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 Yes Stop to recheck only if breathing resumes, else continue until: Qualified help arrives Normal breathing You are exhausted

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 Rescue breaths (RB) Monitor effectiveness: Don’t over ventilate Sight Feel Sound Appearance

Medical Conditions

Diving Illness and Treatment Review Oxygen Exposure At high concentrations oxygen is toxic PO 2 <0.16 bar does not support life Need to remain within accepted oxygen exposure limits Hyperoxic Oxygen Partial Pressure Scale (bar) Short term toxicity risk Long term toxicity risk Hypoxic Unconsciousness Abilities impaired AIR Inspiration default set points Low High

Diving Illness and Treatment Review Hypoxia What is it: Lack of oxygen PO 2 < 0.16 bar Hypoxic Unconsciousness Abilities impaired AIR

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! Hypoxic Unconsciousness Abilities impaired AIR

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 PO 2 >0.5 bar for long periods Central Nervous System (CNS) toxicity when PO 2 >1.4 bar for even short periods Hyperoxic Short term toxicity risk Long term toxicity risk AIR

Diving Illness and Treatment Review Whole Body Toxicity Cause: long exposures to PO 2 >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 CNS Toxicity Also known as Acute Oxygen Toxicity Reaction to PO 2 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 CNS Toxicity Convulsions Tonic phase – do not assist oMuscles become tense oCasualty becomes rigid and holds breath Clonic phase – do not assist oMay occur seconds or minutes after the tonic phase oCasualty jerks violently (convulsion) Depressive phase - assist oCasualty relaxes and is unconscious oPotential loss of mouthpiece –Loop flood – loss of buoyancy –Need for Basic Life Support?

Diving Illness and Treatment Review CNS Toxicity Convulsions Phases can occur on surface or after PO 2 is reduced (‘Off effect’) Progressive damage to nervous system with each successive convulsion

Diving Illness and Treatment Review Hyperoxia Causes: Inaccurate dive planning Failure to analyse gas Incorrect marking or fitting of cylinders Hyperoxic Short term toxicity risk Long term toxicity risk AIR

Diving Illness and Treatment Review Hyperoxia Aggravating factors Actual PO 2 Duration of exposure Level of exertion Cumulative O 2 exposure Hyperoxic Short term toxicity risk Long term toxicity risk AIR

Diving Illness and Treatment Review Hyperoxia Avoidance: High PCO 2 predisposes to oxygen toxicity Accurately track your oxygen exposure Hyperoxic Short term toxicity risk Long term toxicity risk AIR

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 Hypercapnia What is it: Excess CO 2 in the blood Cause: High inspired PCO 2 oPoor ventilation of diver’s lungs at depth due to increased gas density oAbsorbent material exhausted in rebreathers oChannelling in absorbent material rebrerathers

Diving Illness and Treatment Review Hypercapnia Symptoms 0.03 bar PCO 2 doubles breathing rate (dyspnea) 0.06 bar PCO 2 distress, confusion, lack of coordination 0.10 bar PCO 2 severe mental impairment 0.12 bar PCO 2 loss of consciousness, death

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 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 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 Decompression Illness (3) Lie casualty down flat Keep casualty quiet Administer 100% oxygen oIncreased nitrogen pressure gradient assists in nitrogen elimination from bubbles in blood and tissue oThe higher the percentage of oxygen the more effective – whenever possible administer 100% oImproved 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 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 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 Burst Lung (3) Lie casualty down Keep casualty quiet Administer 100% oxygen oAssists in re-absorption of the nitrogen content of air in pneumothorax or emphysema oOffsets 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 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 Near Drowning (2) Rescue Breathing oOxygen-enriched if possible oConcentration of oxygen reaching the casualty’s lungs during RBs is increased Chest compressions if required Recovery position Evacuate to medical attention oEven if apparently fully recovered oComplications of secondary drowning On-site first aid

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 Shock (2) Signs and symptoms weakness, dizziness pallor, sweating rapid pulse rate rapid breathing, feeling breathless unconsciousness

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 oxygen oIncreased 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 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 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 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 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 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

CasualtyAssessmentCasualtyAssessment

Diving Illness and Treatment Review Incident Procedure - Front

Diving Illness and Treatment Review Incident Procedure – Back

OXYGEN ADMINISTRATION EQUIPMENT

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 ) 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 Oxygen Characteristics A colourless, odourless, tasteless gas Comprises approximately 21% of the atmosphere (by volume) An essential component of metabolism Carried in the blood stream oPrimary means - combined with the haemoglobin oSecondary 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 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 IN PRACTICE

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 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 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 O 2 toxicity? – administer O 2 on surface once any signs or symptoms have disappeared No pain killers

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 Evacuation Don’t delay call to emergency services Coastguard: VHF Channel 16 DDMO / BHA DCI Helplines: England, Wales & N. Ireland: Scotland: 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 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 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 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 DDMO 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

Diving Illness and Treatment Review Diving 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