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Factors which upset a diver's emotional equilibrium can contribute to panic. Some of these contributing factors are tabulated as follows: Personal Factors Fatigue Physical unfitness or disability Previous medical disorders Seasickness and/or vomiting Alcohol or drugs Inexperience Inadequate dive plan Dangerous techniques e.g. buddy breathing, free ascents Psychological problems e.g. excessive general anxiety, phobias Sensory deprivation – night diving, blue orb syndrome, solo diving Vertigo and/or disorientation Equipment Problems Buoyancy Snorkel Face Mask Weight Belt Wet Suit Scuba Cylinder Regulator Low or Out-of-Air Situations Other Equipment faults Excessive reliance on equipment e.g. B.C.s Loss of equipment e.g. face mask or fins Excess weights Entrapment in lines, nets, harness etc. Environmental Hazards o Tidal currents o Entry or exit problems o White water e.g. surf o Kelp o Caves, wrecks o Ice and cold water o Deep diving – nitrogen narcosis, rapid air consumption, reduced buoyancy o Dangerous marine animals o Poor visibility o Night diving o Explosives o Boat accidents Chapter 7 — 4
Consider the following scene, which has been gleaned from several diving fatalities, to illustrate some of the factors contributing (in italics) to a panic-related death. Case history. Harry was a recently qualified diver who had borrowed equipment to undertake an open ocean dive in an unfamiliar area. His borrowed wetsuit was a little tight around his chest, restricting his breathing. He decided to use two extra weights on his weight belt to help him descend in the ocean conditions, which were somewhat foreign to him. He was inexperienced at open ocean diving and the conditions were regarded as marginal so he felt a little uneasy about the dive. His companions were more experienced than him and he was unsure of his ability to make his air supply last as long as his buddies. After all, he did not want to be the first to run out of air and force his buddies to shorten their dive. During the dive he was sure he was using more air than the others but he had no way of checking this as his borrowed scuba set did not have a contents gauge . He became a little more apprehensive. They seemed to have swum a long way both from the dive boat and the shore. But he did not want to inconvenience his buddy or embarrass himself by ascending and checking his distance from shore or inquire about his buddies air supply. He had no idea how much air he had left but he felt that there probably wasn't much. He became a little more anxious and his breathing rate increased. He noted some restriction to breathing. Was this just resistance in his regulator or was he now running out of air He activated his reserve valve. Perhaps this would improve the restricted gas flow. It didn't. There was a tidal current running, which slowed their progress to the planned end of the dive – the safe exit point. He was hoping that his companions were also running out of air, as he appeared to be. He was becoming more anxious. His heart was pounding and his breathing rate was increasing. It was becoming harder to get sufficient air from his demand valve. The difficulty in obtaining enough air settled the matter. He decided to get to the surface, fast. In spite of his rapid ascent, he still did not seem to be getting more air from his demand valve. He must be out of gas. He burst through the surface, gasping for breath. He wrenched off his face mask and demand valve and gasped air. The water was choppy and waves washed over his face. He kicked hard with his fins to stay on the surface. One of the ill-fitting borrowed fins came off. A wave washed over his face and he inhaled water and started coughing. It was a real struggle to stay on the surface, he was becoming exhausted. He wondered how long he could keep this up. He tried to keep his head well above the waves, but could not. His buddy noticed he was missing and after a brief search, surfaced. Harry was no where to be seen. An organised search later found his body on the bottom, immediately below where he had surfaced. His weight belt was still fastened, his buoyancy vest uninflated. There was ample air in his cylinder and testing of his demand valve revealed normal functioning, but demonstrating the usual resistance with high gas flows. The autopsy report read "drowning". The real cause was "death from panic". Chapter 7 — 5
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Diving Medicine for Scuba Divers 4t
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ACKNOWLEDGMENTS ! For the 1 st and
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Chapter 1 All chapters, full text,
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The development of self-contained a
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Water is much denser than air and 1
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This law can easily be demonstrated
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For example, if diver has a maximum
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Stated in another way; if a gas is
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Henry's Law This law describes the
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O 2 supports combustion vigorously
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BUOYANCY It is important for divers
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the water temperature decreases wit
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Page 30 and 31: Below the larynx the air passes thr
Page 32 and 33: Gas Uptake and Loss Air, which cont
Page 34 and 35: In venous blood, the haemoglobin in
Page 36 and 37: Circulation The blood flow from the
Page 38 and 39: educes the safety margin in the eve
Page 40 and 41: infections, hypothermia, panic and
Page 42 and 43: BREAK POINT Fig 4.2 . . This diagra
Page 44 and 45: MEDICAL CHECKLIST FOR SNORKELLERS H
Page 46 and 47: Some face masks are fitted with a o
Page 48 and 49: Snorkel The snorkel allows the dive
Page 50 and 51: A poorly fitting wet suit can cause
Page 52 and 53: entanglement with other equipment i
Page 54 and 55: 1. Air supply, cylinder, tank 2. On
Page 56 and 57: Difficulties are still encountered
Page 58 and 59: STANDARD DRESS or HARD HAT This tra
Page 60 and 61: Closed and Semi-closed Circuit REBR
Page 62 and 63: the B.C. to be inflated using air f
Page 64 and 65: The scuba tank may be negatively bu
Page 66 and 67: Diving Watch A reliable, accurate,
Page 68 and 69: Surface detection aids include: •
Page 70 and 71: The "Half Tank Rule". The best tech
Page 72 and 73: It is important to return to the su
Page 74 and 75: The problems centre on impaired vis
Page 76 and 77: The lower surface pressure also mea
Page 78 and 79: In general, successful military div
Page 82 and 83: The above story illustrates some of
Page 84 and 85: Women divers must be doing somethin
Page 86 and 87: convenience, most women today prefe
Page 88 and 89: Other Diving Diseases In a number o
Page 90 and 91: ! Decompression sickness. As mentio
Page 92 and 93: Chapter 9 All chapters, full text,
Page 94 and 95: vibrate. These vibrations are trans
Page 96 and 97: Fig. 9.5 If equalisation does not o
Page 98 and 99: If the ear drum was perforated, com
Page 100 and 101: The diver should then equalise ever
Page 102 and 103: If reasonable, avoid the use of hoo
Page 104 and 105: One or more of these must be presen
Page 106 and 107: There are four main groups of sinus
Page 108 and 109: TREATMENT Any case of suspected sin
Page 110 and 111: Chapter 11 All chapters, full text,
Page 112 and 113: Fig. 11.2 The various clinical mani
Page 114 and 115: Fig 11.3 The location of the medias
Page 116 and 117: Occasionally a valve effect allows
Page 118 and 119: The air bubbles obstruct or damage
Page 120 and 121: Predisposing Factors ! Breath-holdi
Page 122 and 123: In many navies free ascent training
Page 124 and 125: ! Out of Air (OOA) and Low on Air (
Page 126 and 127: PULMONARY BAROTRAUMA OF DESCENT (LU
Page 128 and 129: This condition is easily prevented
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SUIT BAROTRAUMA OF ASCENT ("BLOW UP
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SATURATION When tissues are subject
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DIVE PROFILES The type of dive has
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! Cold. Diving in cold conditions m
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A very short surface interval may a
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ased on modified Haldane principles
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DECOMPRESSION METERS and COMPUTERS
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! Safety suggestions (the DC Ten Co
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ONSET OF SYMPTOMS The clinical feat
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confined within the solid bone of t
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SKIN MANIFESTATIONS of DCS These ar
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The ABBREVIATED MENTAL TEST SCORE (
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Unfortunately 100% O 2 can be toxic
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Transportation in aircraft presents
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Other tables are available which in
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! Slow ascent rates. A slow ascent
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epeated minor trauma which is commo
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Prevention Avoidance of the known p
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CAUSES OF NITROGEN NARCOSIS The exa
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A diver who can "hold his liquor" i
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CLINICAL FEATURES The first sign is
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obstruction somewhere in the respir
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the lungs and body into the counter
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CAUSES OF O 2 TOXICITY For resuscit
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Pulmonary Effects These effects wil
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Clinical Features A person hyperven
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CO 2 toxicity may increase the like
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CLINICAL FEATURES Symptoms are thos
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If the compressor is operated in an
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eaches the surface. If the diver is
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TREATMENT Rescue and recovery from
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PREVENTION It is paradoxical that d
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Fig. 27.3 Graph illustrating surviv
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PREVENTION Alcohol and other drugs
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Occasionally this disorder has been
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! Treatment. All coral cuts should
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! Vibrio and other Aquatic Organism
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SWIMMING POOL GRANULOMA Also called
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Until the risk is excluded it would
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MARINE Chapter 29 All chapters, ful
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! Stop the blood loss. This must be
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The venom has its most serious effe
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IRUKANDJI SYNDROME This disorder wa
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The first aid basic life support me
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hospital as soon as possible. Serio
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The spine may produce a puncture an
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Middle Ear Disorders Disturbances o
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CAUSES OF VERTIGO Problems arising
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Nitrogen narcosis may aggravate ver
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CRAMPS Cramp is a painful spasm of
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Air emboli and bubble development i
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Cold water entering an ear canal ca
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unconsciousness have been well reco
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SEASICKNESS This is a distressing a
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EXPLOSIONS - UNDERWATER BLAST This
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In addition to these the causes ass
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COLD OR HYPOTHERMIA (SEE CHAPTERS 3
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GENERAL MEDICAL CONDITIONS A variet
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! Major Causes of Death identified
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unfortunately promoted by some inst
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Fig 34.3 But not always ! Buddy res
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Salt Water Aspiration This factor w
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Nitrogen Narcosis This was an effec
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Other Equipment Problems In 5% or l
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SUMMARY Diving fatalities generally
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CONTRIBUTING CAUSES There are a num
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This reflex is present to some exte
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! Myocarditis. Some viral infection
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Flora Fisk Quiz for Recreational Di
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(50 ft) and admitted to being "bent
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is undertaken. Then a drug reaction
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Antihistamines These are usually ta
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PROPHYLACTIC (PREVENTION) DRUGS Sta
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Marijuana — Cannabis or "pot" Chr
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Some antibiotics may have no direct
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The hearing function test (pure ton
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MEDICAL EXAMINATION FORMAT There is
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Chapter 38 — 9
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Chapter 38 — 11
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RESUSCITATION EQUIPMENT • Airways
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INFORMATION NEEDED about a DIVING A
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in medicine have 100% O 2 delivered
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compatible. Otherwise the diving il
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GENERAL INFORMATION Oxygen Toxicity
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CHECK LIST FOR DIVING ACCIDENTS INF
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D and R - DANGER and RESPONSE DANGE
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If the rescuer has the equipment an
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Duration of CPR Continue CPR until:
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THE TECHNICAL DIVE 1. DIVE PROTOCOL
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For the same depth/duration dive, t
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OXYGEN ENRICHED AIR or NITROX (EANx
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likely to oxidise and have a higher
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There is also a greater conductive
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The carbon dioxide absorbent must b
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• The oxygen rebreathers are clos
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CONCLUSION There are few problems i
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The actual incidence is unknown, bu
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Appendix A All chapters, full text,
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DIVING MEDICAL TEXTS • *Diving Me
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Appendix B All chapters, full text,
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Appendix C All chapters, full text,
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Appendix D All chapters, full text,
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