Transcript Heat and Cold Emergencies

Heat Emergencies
Prepared by: Steven Jones, NREMT-P
Thermoregulation
• Homeostasis requires stable temperature
• ~98.6ºF
• Control mechanism
• Hypothalamus
• Peripheral thermoreceptors
• Balance between heat production, heat loss
Heat Production
• Metabolism
• Voluntary large muscle movement
• Shivering
Heat Induced Illness
• Results from:
• Increase in body temperature outside normal range
• Prolonged efforts to compensate; profuse sweating
• Dehydration
Hyperthermia
• Caused by
• Overwhelmed thermoregulatory system
• Environmental conditions (exogenous)
• Excessive exercise (endogenous)
• Excessive clothing
• Drugs ? ?
• Methamphetamines are notorious for causing a rapid ↑ in
body temperature
• Failure of thermoregulatory system
• CVA
Heat-Related Illness
• Heat Cramps
• Heat Exhaustion
• Heat Stroke
Heat Cramps
Heat Cramps
• Pathophysiology
• Hot environment causes profuse sweating
• Na+ (sodium) lost in sweat
• Lack of Na+ causes muscle cramping
Heat Cramps
• Signs/Symptoms
• Patient usually in good condition; working in hot, humid
environment
• Cramps of fingers, arms, legs, abdominal muscles
• Nausea
• Normotensive, mild hypotension
• Tachycardia
• Cool, pale skin
• Awake, alert, normal body temperature
Heat Cramps
• Management
• Move to cool place, rest, lie down
• Give balanced salt/water solution (Electrolyte Solution)
• Salt alone leads to increased nausea, increased water loss
• Water alone leads to worsened cramping (dilutional
hyponatremia)
Heat Cramps
• Management
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IV NaCl if patient too nauseated to drink
Avoid massaging muscles
Avoid activity
Increase fluid, Na+ intake
Heat Exhaustion
Heat Exhaustion
• Pathophysiology
• Increased vascular space due to vasodilation
• Decreased blood volume due to sweating
• Decreased CNS perfusion
Heat Exhaustion
• Epidemiology
• People working in hot, humid environments
• Elderly, due to decreased thirst mechanism
• Hypertensives, due to medication effects
Heat Exhaustion
• Signs/Symptoms
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Headache, dizziness, fatigue, nausea, confusion
Weakness, syncope
Profuse perspiration, pallor
Tachycardia, hypotension, tachypnea
Orthostatic changes
Normal core temperature
Heat Exhaustion
• Management
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Move to cool place, stop activity, lie down
Supine, legs elevated
Sponge with cool water, fan
Balanced salt/water (electrolyte) solution, or
IV with NaCl, if too nauseated to drink
Assess glucose if altered mental status
Heat Exhaustion
• Management
• Transport indicated if:
• Loss of consciousness occurs
• Underlying cardiovascular disease
• Oxygen, EKG monitor if transport indicated
Heat Stroke
Heat Stroke
Altered LOC + Hot Environment =
THINK - Heat Stroke
Heat Stroke
• Pathophysiology
• Body heat accumulation leads to increased
temperature above 1060F
• Increased temperature damages hypothalamus:
• Heat regulating mechanism failure occurs
• 25 - 50% mortality in elderly
Types of Heat Stroke
• Exertional Heat Stroke
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Occurs in healthy, young people in hot environments
Heat builds up faster than it is removed
Damage to hypothalamus occurs
Patient sweats heavily
Types of Heat Stroke
• Classic Heat Stroke
• Elderly, alcoholics, obese, heart disease patients,
phenothiazine users
• Body heat builds up slowly over several days
• Dry skin, absence of sweating
Heat Stroke
• Signs/Symptoms
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Headache, dizziness, irritability
Decreased LOC, seizures
Bounding pulse progressing to rapid, weak pulse
Hypotension secondary to vasodilation
Presence or absence of sweating is NOT a
reliable sign
Heat Stroke
• Management
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Secure airway
High concentration oxygen
Rapid cooling to 1020 F
IV NaCl
• Avoid volume in classic heat stroke
• Exertional heat stroke may need volume replacement
• Monitor EKG
Heat Stroke
• Management
• Drugs as necessary
• Glucose for hypoglycemia
• Diazepam for seizures, PRN
• Reassess for secondary complications
• Cardiac dysrhythmias
• Pulmonary edema
• Rapid Transport
Heat Emergencies