Post on 05-Apr-2018
8/2/2019 Wilderness Medicine & Hypothermia
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Strategies for TreatingHypothermia
How to deal with low core bodytemperature?
Joshua Bennett M1073
8/2/2019 Wilderness Medicine & Hypothermia
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Relevance to Wilderness Medicine
Medical emergency
>50% mortality in patients aged 70 or olderwith temperature <32°C (Longmore et al., 2010)
Personal experience
Why I chose to talk about this
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1 hour from car park, notice youngman slumped against stone wall.
Mumbling inaudibly and shivering
violently. Half empty bottle of vodka.
Equipment is your backpack
containing what you wouldnormally take for a day outdoors.
What would you do?
January 2011, Lake District, Sca Fell
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Grades and types of hypothermia
Need to know basics in order to treat.
Essentials of hypothermia management
Do’s and Don'ts
Strategies to treat hypothermia
Spontaneous rewarming
Active external rewarming
Active core rewarming
Resuscitation and hypothermia
Objectives
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Severity
Grade I – conscious and shivering
Grade II – impaired consciousness / no
shivering
Grade III – unconscious or cardiacinstability
Grade IV – apparent death
Grades of hypothermia
KEY POINT: Cold patients who have stoppedshivering will cool at an accelerating rate (due to
minimal heat generation).
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Severity
Grading system
Speed of onset
Acute / immersion
Subacute / exhaustion / injury
Subchronic / urban
Types of hypothermia
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irway
reathing
irculationisability
Where hypothermia management
fits
nvironment / evacuation
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Hypothermia physiology
KEY POINT: ‘Core afterdrop’ or ‘rewarming collapse’
can occur if rewarming is too quick.
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Do:
Remove from cold
Replace wet
clothing Insulate
Handle gently
Monitor regularly
For any hypothermic patient...
Don’t:
Suppress shivering
Give alcohol
Put in warmshower/bath
Warm peripheries
KEY POINT: Sudden movements may trigger
ventricular fibrillation.
(NESRA Medical Sub-Committee, 2010)
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Spontaneous rewarming
May reverseGrade Ihypothermia
Requires patient togenerate heat
Layer system
Insulate fromground
Cover head andneck (leave
airway!)
‘Hypothermia wrap’
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Active external rewarming
Indications:
Grade II hypothermia or worse
Trauma or other co-morbidity Apply heat source to armpits, groin and
flanks
Should be warm not hot- risk of burningpatient
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Airway warming
Air humidifier devices
Warm tubing in warm drink
Warmed IV fluids Microwave
Can warm giving set in warm drink
Thoracic lavage
Peritoneal dialysis
Cardiopulmonary bypass
Active core rewarming
invasive
(Danzl and Lloyd, 2001)
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Check carefully for pulse for
1 minute “No-one is dead until they
are warm and dead” >33°C
Resuscitation and hypothermia
“Active core rewarming techniques are the primarytherapeutic modality in hypothermia victims incardiac arrest or unconscious with a slow heartrate.”
(Emergency Cardiac Care Committee, 1992)
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1 hour from car park, notice youngman slumped against stone wall.
Mumbling inaudibly and shivering
violently. Half empty bottle of vodka.
Equipment is your backpack
containing what you wouldnormally take for a day outdoors.
What would you do?
January 2011, Lake District, Sca Fell
8/2/2019 Wilderness Medicine & Hypothermia
http://slidepdf.com/reader/full/wilderness-medicine-hypothermia 15/16
Summary
KEY POINT: Cold patients who have stoppedshivering will cool at an accelerating rate (due to
minimal heat generation).
KEY POINT: ‘Core afterdrop’ or ‘rewarmingcollapse’ can occur if rewarming is too quick.
KEY POINT: Sudden movements may trigger
ventricular fibrillation.
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References Danzl, D. F. and Lloyd, E. L. (2001) Medical
Aspects of Harsh Environments. Borden Institute. Emergency Cardiac Care Committee. (1992)
'Guidelines for Cardiopulmonary Resuscitationand Emergency Cardiac Care', Journal of the American Medical Association.
Longmore, M., Wilkinson, I. B., Davidson, E. H.,Foulkes, A. and Mafi, A. R. (2010) Oxford
Handbook of Clinical Medicine.8th ed: NESRA Medical Sub-Committee. (2010) Mountain
Rescue for Casualty Care student notes.2nd ed:
Questions?