JOINT SERVICE SUB AQUA DIVING

1. JOINT SERVICE SUB AQUA DIVING DIVING ILLNESS’ & TREATMENT REVIEW

2. 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

3. Outline • BLS • In-Water Rescue • Medical conditions Casualty Assessment • Oxygen administration equipment • Oxygen administration in practice

5. BASIC LIFE SUPPORT (BLS)

6. 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 oxygen-enriched basic life support

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

8. Assessing the Need • Indicators of the need for BLS: • No response • No chest movement • No feel of air movement

9. Priorities • D r A B C • Danger – to casualty and rescuer • Response (AVPU) • Airway • Breathing • Compressions

10. Airway blocked by tongue • Head tilt/chin lift clears airway Clear Airway • Foreign objects • Tongue

11. Priorities • Danger– to casualty and rescuer • Response • A–Alert • V–Responds toVoice • P–Responds toPain • U–Unresponsive • Airway– clear of obstructions • Breathing– check for normal breathing (10 secs.) • Compressions – Cardiac Compressions

12. BLS: Decision Process • Unresponsive • Leave casualty and get help • No • Yes • Shout for help, open up airway • Breathing normally? • Leave casualty and get help, • return & give 30CCs • No • Yes • Stop to recheck only if breathing resumes, else continue until: • Qualified help arrives • Normal breathing • You are exhausted • Recovery position

13. 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

14. 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

15. Don’t over • ventilate 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

16. Don’t over • ventilate 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

17. Recovery Position • If casualty breathing place in recovery position • More stable position • The ‘how’ position

19. IN-WATER RESCUE

20. 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

21. 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 • Controlled • Buoyant Lift • AS ascent

22. 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 • Remove mask, mouthpiece and give RB for 1 minute i.e. 10RBs

23. 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

24. 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

25. 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

26. Pre-Dive Buddy Awareness • Buddy reactions • Stopping for no reason • Preoccupation with kit • Slow response to signals • Rapid breathing • Wide staring eyes • Resolve quickly • Stop or move to buddy • OK? Problem? • Not OK, gentle but firm contact • Abort dive

28. MEDICAL CONDITIONS

29. Oxygen Partial Pressure Scale (bar) • Abilities impaired • Hypoxic • Hyperoxic • Long term toxicity risk • .08 • .10 • .16 • .21 • .5 • 1.0 • 1.4 • 1.6 • Unconsciousness • Short term toxicity risk • AIR Oxygen Exposure • At high concentrations oxygen is toxic • PO2<0.16 bar does not support life • Need to remain within accepted oxygen exposure limits

30. Abilities impaired • Hypoxic • .08 • .10 • .16 • .21 • Unconsciousness • AIR Hypoxia • What is it: • Lack of oxygen • PO2< 0.16 bar

31. Abilities impaired • Hypoxic • .08 • .10 • .16 • .21 • Unconsciousness • AIR 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!

32. Long term toxicity risk • Hyperoxic • .21 • .5 • 1.0 • 1.4 • 1.6 • Short term toxicity risk • AIR Hyperoxic • What is it: • Too much oxygen • Oxygen becomes toxic at elevated partial pressures • There are two different effects of Hyperoxia: • Whole Body Oxygen Toxicitywhen PO2>0.5 bar for long periods • Central Nervous System (CNS)toxicity when PO2>1.4 bar for even short periods

33. 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)

34. 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

35. 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?

36. CNS Toxicity • Convulsions • Phases can occur on surface or after PO2 is reduced (‘Off effect’) • Progressive damage to nervous system with each successive convulsion

37. Long term toxicity risk • Hyperoxic • .21 • .5 • 1.0 • 1.4 • 1.6 • Short term toxicity risk • AIR Hyperoxia • Causes: • Inaccurate dive planning • Failure to analyse gas • Incorrect marking or fitting of cylinders

38. Long term toxicity risk • Hyperoxic • .21 • .5 • 1.0 • 1.4 • 1.6 • Short term toxicity risk • AIR Hyperoxia • Aggravating factors: • Actual PO2 • Duration of exposure • Level of exertion • Cumulative O2 exposure

39. Long term toxicity risk • Hyperoxic • .21 • .5 • 1.0 • 1.4 • 1.6 • Short term toxicity risk • AIR Hyperoxia • Avoidance: • High PCO2 predisposes to oxygen toxicity • Accurately track your oxygen exposure

40. 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

41. CO2 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

42. CO2 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 PCO2loss of consciousness, death

43. CO2 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

44. Bubbles blocking blood flow • Bubbles in tissues compress blood vessels 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 • Patent foramen ovale (PFO) allows bubbles to pass from venous to arterial circulation

45. 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 • Signs and symptoms appear from seconds to many hours after surfacing

46. Decompression illness On-site first aid • 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

47. Bubbles between organs and tissues (emphysema) • Collapsed lung • (pneumothorax) Burst Lung • Cause • Physical damage to lung tissue from over-extension due to over-pressurisation • Types • Both types can occur in isolation but are usually accompanied by air embolism

48. 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

49. 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

50. Near Drowning • Cause • Respiratory interruption due to fluid inhalation • Signs and symptoms • Circumstances • No breathing • Cyanosis – ashen grey / blue appearance • Weak or absent pulse