04/22/23 Ken Zafren, MD FACEP Hypothermia Guidelines
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Revised Cold Injuries and Cold Water Near Drowning Guidelines
Ken Zafren, MD, FACEPEMS Medical Director,State of Alaska
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The State of Alaska Cold Injuries and Cold Water Near Drowning Guidelines Developed in 1988 by an expert
panel Revised in 1996 Expert panel revision - Sitka 2002 Revised edition in progress
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Overview of Guidelines General points Hypothermia Cold water near drowning Frostbite New section on avalanche rescue
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Introduction Guidelines - not absolute rules Designed as a reference, not a
teaching document
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Multilevel guidelines
General points General public First Responder / EMT-I EMT-II EMT-III / Paramedic Small/Bush Clinic Hospital
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Hypothermia -General Points
Core temperature best measured as esophageal temperature if possible
Epitympanic temperature second choice
Rectal temperature third choice
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Hypothermia -General PointsWhy esophageal temperature?
Best reflection of core temperature Reflects cardiac temperature Relatively non-invasive Technology widely available Patient remains covered
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Hypothermia -General PointsEpitympanic temperature
Reflects carotid artery temperature Non-invasive Technology not yet widely
available in USA
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Hypothermia -General PointsRectal temperature
Does not reflect core temperature very well
Lags core temperature during rewarming
Requires disrobing patient
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Hypothermia - General PointsOrthopedic injuries Splint with caution in frostbitten
limbs to prevent further damage; frostbitten skin is damaged skin.
Align fractures/dislocations in neutral position. This gives the best chance of preserving neurovascular and other structures.
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Hypothermia - General PointsOrthopedic injuries
Do not reduce frozen extremities to prevent further damage.
Splints should not be constrictive in order to allow for postinjury swelling.
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Hypothermia - General Points
Warm oral and IV fluids to at least body temperature to prevent further cooling.
Give IV fluids as boluses (especially for field use).
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Hypothermia - General PointsWhy IV fluid boluses? Less likely to freeze than
continuous infusions Better titration to effect
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Hypothermia - General Points
Chemical heat packs ineffective for warming
Can be used on hands or feet to prevent frostbite
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Hypothermia - General Points
Positive attitude is important Assume the patient can be
resuscitated even if they appear to be beyond help
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Hypothermia - General PointsContraindications to CPR New temperature cutoff - core
temperature 10°C/50°F Rescuers exhausted or in danger
or CPR cannot be maintained throughout transport to a medical facility
Transportation available within 3 hours
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Hypothermia - General PointsContraindications to CPR - new cutoff New temperature cutoff - core
temperature 10° C / 50° F Survival has now been
documented to core temperature of 13.7° C / 56.7° F
Routine use of 10° C / 50° F in surgery
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Hypothermia - General PointsContraindications to CPR Rescuers exhausted or in danger
or CPR cannot be maintained throughout transport to a medical facility
If CPR is begun any perfusing rhythm will probably be lost; stopping CPR once begun is therefore likely to be fatal
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Hypothermia - General PointsContraindications to CPR Transportation available to critical
care within 3 hours Hypothermic patients can survive
for up to 3 hours with pulse and blood pressure which are difficult to detect.
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Hypothermia - General PointsCPR Apneic pulseless patient - ventilate
for 3 minutes before CPR to increase VF threshold
Ventilation may increase heart rate, blood pressure
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Hypothermia - General PointsCPR
Apneic pulseless patient - decision to start CPR based on time to critical care
<3 hours: ventilate (intubate, if possible), prevent heat loss
>3 hours: chest compressions and ventilate for 30 minutes, attempt to rewarm
CPR cannot be done in a litter
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Handle hypothermic patients gently to prevent Ventricular Fibrillation
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Hypothermia - General PointsAssessment Check for cardiac activity for at
least 60 seconds Automatic External Defibrillator
(AED) may be used to detect cardiac activity - signal to shock indicates V Tach or V Fib
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Hypothermia - General PointsAssessment New classification for severity of
hypothermia Follows International Commission
for Alpine Rescue, Winnepeg consensus guidelines
Correlates core temperature with observable findings
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Classifications of level of hypothermia
Core temp Thermoregulatorystatus
S & S Classifications
37 oC Cold sensationshivering
Normal
35-32 oC Control andresponses fullyactive
Physicalimpairment finemotorGross motor
MentalimpairmentComplexSimple
mild
32-28 oC Responsesattenuatedextinguished
-30 degreesshivering shopsloss of consciousness
moderate
Below 28 oC Responses absent RigidityVital signs reduced or absentRisk of VF (rough handling)
Below 25 oC Spontaneous ventricular fibrillationCardiac arrest
Severe
Red text are major thresholds between stages
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Hypothermia stages Mild 32-35°C (90-95°F) Moderate 28-32°C (82-90°F) Severe <28°C (<82°F) Ideally based on esophageal
temperature Becoming standard classification
worldwide
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Hypothermia - General PublicMild Hypothermia Patient is cold Vigorous shivering Alert May be ambulatory
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Hypothermia - General PublicTreatment
Remove wet clothes only with shelter
Vapor barrier Cover head and neck
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Hypothermia - General PublicTreatment
Shivering is an important method to increase heat production
Sugar containing fluids are more beneficial than hot drinks
Special importance if medical care delayed
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Hypothermia - General PublicTreatment
Mild exercise such as walking may be helpful after the patient is dry and has eaten
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Hypothermia - General PublicTreatment
Mild exercise such as walking may be helpful after the patient is dry and has eaten. If the patient is exhausted, exercise cannot be maintained and the patient will lose the ability to increase body heat (primarily by shivering)
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Hypothermia - General Public Moderate-Severe Treatment Handle gently Do not rub or manipulate
extremities
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Hypothermia - General Public Moderate-Severe (with life signs)Treatment Handle gently Do not rub or manipulate
extremities Do not allow to sit or stand Do not put in shower or bath No exercise
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Hypothermia - General Public Moderate-Severe (without life signs)Treatment Handle gently Check pulse for at least 60
seconds CPR if not contraindicated
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Hypothermia -First Responder EMT-I
Same as general public with additions
Oxygen, if used, should be heated and humidified
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Hypothermia -First Responder / EMT-I
Insulate patient - sleeping bag Cover head and neck Rewarming axilla, trunk, groin Hot shower/bath okay only for mild
hypothermia
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Hypothermia - EMT-II
Same as EMT-I with additions Most patients need volume IV fluid should be normal saline -
250 cc boluses, repeated as needed to treat tachycardia
Heat fluid to 104-108°F (40-42°C) Consider glucose, naloxone
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EMT-IISevere hypothermawith signs of life Measure core temperature
(esophageal is preferred)
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EMT-IISevere hypothermawithout signs of life Ventilate and pre-oxygenate 3
minutes before intubating Intubate Do not hyperventilate One set of defibrillations if core
temperature is less than 30°C (86°F)
Further attempts above 30°C
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EMT-III / ParamedicSevere hypothermawithout signs of life Same as for EMT-II No ACLS drugs No CPR if any rhythm on monitor
other than VF/VT
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Hypothermia - HospitalGeneral Points Treat to level of ability Transfers follow usual guidelines May be better to bypass
community hospital for one with cardiac bypass capability
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Hypothermia - HospitalGeneral Points Consider transfer of patient with
core temp <20° C (68° F) Consider bypass if BP<60 systolic Stabilize patient before transport
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Hypothermia - HospitalGeneral Points
Suggestions for evaluation and treatment
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Hypothermia - HospitalGeneral Points Esophageal temperature and end
tidal CO2 monitoring IV fluids must be heated. Heated, humidified oxygen, if
available Avoid sedation to depress
shivering
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Hypothermia - HospitalGeneral PointsRewarming methods Passive external rewarming Active external rewarming Active core rewarming
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Hypothermia - HospitalGeneral PointsActive internal rewarming Peritoneal lavage AV Rewarming Cardiopulmonary bypass Venous heat-exchange catheter
(possible future technology)
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Hypothermia - HospitalGeneral PointsActive internal rewarming Slow rewarming prior to adequate
ventilation
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Hypothermia - HospitalGeneral PointsCardiac rhythm disturbances Supraventricular dysrhythmias are
innocent V Tach and V Fib - one round of
shocks until 30°C (85°F) Drugs ineffective
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Hypothermia - HospitalGeneral PointsInsulinConsider insulin during rewarming.
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Hypothermia - HospitalWhen to stop resuscitation? Core temperature not improving
despite aggressive rewarming Serum potassium >10 with
associated asphyxia (near drowning, avalanche)
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Cold Water Near DrowningGeneral Points Use of PFDs with thermal
protection mandatory for emergency responders
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Cold Water Near DrowningGeneral Points Submersion - head under water Immersion - head out of water
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Cold Water Near DrowningGeneral Points Hypothermia not the main problem Cardiac, pulmonary and
coagulation problems are key Rewarming to raise temperature to
make defibrillation more effective
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Cold Water Near Drowning - General Public Neck protection if possible injury Activate EMS system Start CPR if patient pulseless after
pulse check of 60 seconds Heimlich maneuver only for solid
foreign body obstruction
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Cold Water Near Drowning - First Responder / EMT-I Similar to General Public
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Cold Water Near Drowning - EMT-II Similar to EMT-I Saline lock or TKO (no fluids)
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Cold Water Near Drowning - EMT-III / Paramedic Similar to EMT-II Assess for possible
cardiopulmonary bypass
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Cold Water Near Drowning - Hospital
IV fluids only if volume depleted Cardiopulmonary bypass no longer
recommended
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Cold Water Near Drowning - Hospital Active external rewarming as
indicated by core (esophageal) temperature.
Keep patients at 32-33° C to protect the brain.
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Cold Water Near Drowning - Hospital Agressive cerebral resuscitation
(IVP monitoring, diuretics, barbiturates) no longer recommended.
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Frostbite
No significant changes in prehospital care
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Frostbite
Temperature for thawing 38-40°C (100-107°F). The lower end is preferred.
Stop thawing when tips of digits flush.
Recommendations for wound care.
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Frostbite
Fasciotomy guided by compartment pressures (>37-40 mm Hg) and clinical judgment
Antibiotics necessary only for deep infection
General care recommendations
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Frostbite
Orthopedic guidelines Guidelines for disposition Sample admitting orders
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Avalanche rescue
Similar to cold water near drowning Importance of asphyxiation
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Avalanche Rescue
Rapid extrication to 35 minutes to prevent asphyxia
Gentle extrication after 35 minutes to prevent ventricular fibrillation in hypothermic patient
Check for air pocket
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Avalanche Rescue
Rapid extrication to 35 minutes to prevent asphyxia
Patients extricated in less than 35 minutes are unlikely to be hypothermic, but will die of asphyxia without an adequate air pocket.
An air pocket is any space in front of the nose or mouth, no matter how small.
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Avalanche Rescue
Gentle extrication after 35 minutes to prevent ventricular fibrillation in hypothermic patient
Patients extricated after 35 minutes who are still alive will have an air pocket.
They are at risk for hypothermia.
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Avalanche Rescue
Rapid extrication to 35 minutes to prevent asphyxia
Gentle extrication after 35 minutes to prevent ventricular fibrillation in hypothermic patient
Check for air pocket
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Avalanche Rescue
CPR/ACLS for 30 minutes for burials less than 35 minutes or core temp >32°C
No CPR/ACLS for burials longer than 35 minutes or core temp <32°C if no air pocket
CPR/ACLS for burials longer than 35 minutes or core temp <32°C with air pocket