COLD%20WATER%20IMMERSION

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COLD WATER IMMERSION
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Cold Water Immersion
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The Cold Facts - Hypothermia and Drowning

• Physiology - What happens when we enter cold
  water
• Why and how does it kill
• How can it be prevented
• What can we do to help

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Setting the StageCase History P04 0589 April
23, 2004 - Duke Point

• Accidental Immersion in cold water can be a
  terrifying experience.
• Were going down. We have 2 kids on board
• You gotta get out here. Its bloody cold. We
  arent going to last long
• This incident fortunately had a happy ending
  rescue of family of four by Sea Shuttle after
  approx 30 minutes in water

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Hypothermia

• Results from the bodys inability to adequately
  replace heat lost to the surrounding environment
• Factors influencing heat loss include water
  temperature, sea state/water circulation, degree
  of immersion, insulating garments, rate of energy
  expenditure, body type, psychological factors
• To err on side of safety, we assess as either
  mild or severe

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Submersion Incidents Drowning and Near Drowning

• Drowning is defined as death through suffocation
  by submersion, especially in water
• Near Drowning has been defined as survival, at
  least temporarily, after aspiration of fluids
  into lungs
• Hypothermia is likely biggest factor in survival
  of near drowning/submersion patients

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Drowning

• Laryngeal Spasm May offer some early protection
  from aspiration but hypoxia causes relaxation of
  the vocal cords allowing water into the lungs
• Drowning does not occur without fluid aspiration
  immersion victims without fluid in lungs
  probably did not drown

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Drowning

• Drowning can occur at surface due to wave splash
  over mouth and nose
• Type of water salt water (hypertonic) draws
  fluid into lungs, while fresh water (hypotonic)
  results in osmotic passage of some aspirated
  water into circulation

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Drowning

• Males and children have the highest drowning
  mortality rates
• Prevention works Prevention initiatives in
  developed countries have been successful
• According to the Lifesaving Society of Canada,
  two thirds of drowning victims had no intention
  of entering the water

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Stages of an Immersion Incident

• 1. Cold Shock first few minutes
• 2. Swimming Failure 3-30 minutes
• 3. Long term Hypothermia becoming severe
• 4. Post Rescue

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The Cold Facts Surviving Sudden Cold Water
Immersion
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1. Cold Shock

• Responses, triggered by cold receptors in the
  skin, last just a few minutes (peaking at about
  30 seconds)
• Large inspiratory gasp upon immersion may
  trigger drowning
• Uncontrollable hyperventilation and reduced
  breath hold
• Coordination of swimming stroke and breathing
  very difficult

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1. Cold Shock

• Survival activity often fails
• Aspiration of water is likely leading to near
  drowning or drowning
• Massive increase in heart rate and blood pressure
  may trigger cardiac arrest in older or less
  healthy individual

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2. Swimming Failure

• Cold incapacitates within 3 30 minutes of
  immersion, even before hypothermia sets in
• Water temperatures below 20?C result in
  degradation of swim performance
• Peripheral cooling leads quickly to the loss of
  manual dexterity and muscle strength, with
  resultant inability to self rescue

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2. Swimming Failure

• Even short swims may be impossible many who
  drown are reported to have been good swimmers

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3. Hypothermia

• Water conducts heat away 25 times faster than air
  of same temperature
• Predications of survival times are possible, but
  many variables make these unreliable
• If airway is protected (no drowning), death will
  occur somewhere below 24?C, although the casualty
  is considered vulnerable below 30?C
• Lowest recorded survival is core temperature of
  13.7?C

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4. Post Rescue

• Vulnerable time for the casualty up to 20 of
  immersion deaths
• Circum-rescue collapse drop in blood pressure
  as result of release of hydrostatic pressure and
  vertical positioning during rescue
• Afterdrop the continued decline in core tissue
  temps after removal from cold stress

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4. Post Rescue

• Physical effort by survivor may trigger collapse
  or death
• Rough handling may trigger cardiac arrest (VF)
• VF responds poorly to defibrillation at core
  temps below 28?C

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Sometimes not everyone makes it May 1, 2004
Cape Beale

• 5 persons in the water from over-turned 18
  pleasure craft, spotted by light-keeper
• 1 swam ashore, later recovered by EHS helicopter

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Sometimes not everyone makes it May 1, 2004
Cape Beale

• 4 recovered from water by RHIOT 1 and 2
• despite prolonged resuscitation attempt 1 person
  did not survive (core temp measured at Bamfield -
  22?C)

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Prevention and Survival
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Prevention and Survival

• Training, Preparation, Attitude and Experience
• Avoid entering water unless necessary stay
  with your boat
• Floatation and Insulation objective is warm
  and dry
• A dry suit or immersion suit is best if you must
  enter water

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Rescue of Survivors

• Assess survivor as being either mildly or
  severely hypothermic - based on history, level of
  responsiveness, vital signs and if possible
  temperature
• If possible
• Recover horizontal and keep horizontal during
  transport
• Handle gently - do not allow survivor to aid in
  own rescue

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Rescue of Survivors

• Remember that concerns at point of rescue
  include
• Circum-Rescue Collapse due to drop in blood
  pressure on removal from water
• Core Temperature Afterdrop the continued
  decline in core temperature after removal from
  cold stress

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Treatment

• Remove wet clothing, provide shelter and insulate
  against further heat loss
• Avoid rapid full surface re-warming, alcohol or
  caffeine, and inappropriate speech
• Add heat to high heat loss areas (head and neck,
  chest, groin)

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Treatment

• Evacuate to medical, monitoring continuously

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Resuscitation

• Expect fluid in airway to be a problem foaming
  may be present
• Stiffness may be due to cold rather than rigor
  mortis
• Prior to resuscitation, check carotid pulse for
  up to 45 seconds

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Resuscitation

• Recovery following prolonged submersion is
  possible dont give up
• The casualty is not considered dead until
  they are warm and dead

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Summary

• Hypothermia, Drowning and Near Drowning
• Four stages of an immersion incident
• Prevention and Survival
• Rescue of Survivors

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Summary

• Treatments issues, including resuscitation
• Questions?

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For more information

• World Congress on Drowning www.drowning.nl
• Essentials of Sea Survival Dr. Frank Golden,
  Dr. Michael Tipton Human Kinetics,
  800-465-7301, orders_at_hkcanada.com
• The Cold Facts Surviving Sudden Cold Water
  Immersion (A Canadian Forces
  Production)
• Dr. Chris Brooks Survival in Cold Waters, TP
  13822E http//www.tc.gc.ca/MarineSafety/TP/Tp13822
  /menu.htm

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• With thanks to Bob Ayres
• CCG