Heat and Cold Emergencies Lecture Flashcards
What are the 2 main control mechanisms for thermoregulation?
Hypothalamus
Peripheral Thermo receptors
What are the four modes of heat loss?
Conduction
Convection
Radiation
Evaporation (skin/ respiratory)
Failure of the thermal regulatory system occurs in what 2 main patient populations
Geriatric and Pediatric
Five minor heat related disorders
Dehydration Heat rash Heat edema He tetany Heat syncope
Pathophysiology of heat cramps
Profuse sweating
Excessive sodium loss
Lack of sodium and causes muscle cramps
Signs and symptoms of heat cramps
Hot humid environment Muscle cramping Nausea Normotensive to mild hypertension Tachycardia Cool pale skin Alert Normal temp
Management of heat cramps
Passive cooling and rest
Give electrolyte solution
IV NS
Avoid massage and activity
Pathophysiology of heat exhaustion
Vasodilation
Hypovolemic due to excessive sweating
Decreased CNS perfusion
Signs and symptoms of heat exhaustion
Headache, dizziness, fatigue, nausea, confusion, weakness, syncope Excessive sweating, pallor Tachycardia, hypotension, tachypnea Positive orthostatic Core temp >104
Management of heat exhaustion
Remove from the environment Elevate legs Active cooling IV NS Blood glucose monitor 02 and EKG monitor
Pathophysiology of heat stroke
Body temperature> 106
Two types of heat stroke
Exertional
Classic
Characteristics of exertional heatstroke
Young healthy people
Rapid heat accumulation
Damage the hypothalamus
Excessive sweating
Characteristics of classic heatstroke
Elderly, alcoholics, obese, heart disease patient populations
Slow chronic buildup of heat
Dry skin, absence of sweating
Signs and symptoms of heat stroke
Headache, dizzy, irritable
DLOC, seizure
Bounding pulse progressing to weak and rapid
Hypotension 2nd to vasodilation
ALOC + Hot Environment =
Heat Stroke
Heatstroke management
Secure airway High flow O2 Rapid cooling IV NS EKG Glucose or benzodiazepines as needed for BG or seizure Reassess for dysrhythmias or pulmonary edema Transport
Two classifications of local cold injuries
Non freezing - chilblains, trench foot
Freezing - frostnip, frostbite
What are chilblains
Chronic exposure two damp environments
Painful lesions on skin
Pruritis, burning
Reoccurs
Chilblain treatment
Rewarm, Bandage, elevate
Characteristics OF TRENCH FOOT
Prolonged exposure to cool wet conditions
Skin pale, modeled, Wrinkled
Loss of sensation
Sloughing or gangrene may occur
Treatment of TRENCH FOOT
Clean, warm, dry bandages elevate
Risk factors for frostnip to frostbite
Poor nutrition, diabetes, poor tissue perfusion, vasodilation caused by ETOH or medications
Two phases a frostnip or frostbite pathophysiology
Phase I Cold injury
Phase II Rewarming complications
Describe phase I of frosting/frostbite
Exposure to cold, vasoconstriction, ice crystal formation in extracellular space, ischemia, Cellular dehydration
Describe phase II of frosting/frostbite
Rewarming, capillaries leak fluid, edema, thrombus formation
Frostbite classifications and descriptions
1st degree - partial freezing, mild edema, no blisters
2nd Degree - full thickness freezing, blisters, edema
3rd degree - Subcutaneous freezing, hemorrhagic blisters, skin necrosis, blue-gray
4th degree - damage to muscles, little edema, black, mummified
Management of frostbite
Dry patient Warm IV fluids Dry sterile dressing Pain management Avoid rewarming unless extremely long transport If indicated re-warm and 100-105 degree water Do not allow refreezing Do not massage Do not drain blisters
Temperature below which hypothermia occurs
< 95
Risk factors for hypothermia
Pediatric and geriatric Hypothyroid Diabetes Alcoholic Depression and drug abuse Poor nutrition
Pathophysiology of hypothermia
Vasoconstriction Catecholamine release Initial increased HR, RR, BP Shivering, unless temp < 90 Cardiac arrest if < 86 Ischemic tissues Depression of ADH Cold diuresis Depression of insulin release
Signs and symptoms of hypothermia
Pallor, shivering Ataxic gate Drowsiness, coma Slowing HR and RR Cardiac arrest
ALOC + Cool Environment =
Hypothermia
EKG changes in hypothermia
Bradycardia (may be unresponsive to atropine)
Absent P-wave
Abnormal ST segment’s and T-wave
J wave
Mild hypothermia temperature range
90-95
Mild hypothermia management
Prevent further heat loss
Hot packs to head neck chest groin
Warm oral fluids
Moderate hypothermia temperature range
86-89
Management of moderate hypothermia
Prevent further heat loss
Active rewarming
Warm IV fluids
EKG
Severe hypothermia temperature
< 86
Severe hypothermia management
Secure airway Do not hyperventilate Handle gently Prevent further heat loss EKG IV with NS Active rewarming
Hypothermic cardiac arrest if temperature < 86
1 shock
no meds
Hypothermic cardiac arrest temperature > 86
Increase drug dosing intervals
Repeat shocks has Core temp rises
You are not dead until…
You are warm and dead
