Transcript Combat Casualty Care

HEAT INJURIES
OBJECTIVES

Risk Factors

Types of Heat Injury
*symptoms, cause and treatment

Pre-hospital care

Management
Individual Risk Factors
Poor fitness
 Large body mass
 Minor illness
 Drugs (cold/allergy/blood
pressure/performance enhancing)
 Highly motivated

Types of Heat Injury
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Heat Cramps
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Heat Exhaustion
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Heat Stroke
Heat Cramps
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Painful cramping of the larger muscle groups
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Due to excessive loss of salt through heavy
sweating plus several hours of sustained exertion
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legs, arms, abdomen
acclimatization decreases risk
Treatment
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shaded area
massage arms/legs to increase circulation
0.1% salt solution orally (1/2 tsp salt in 1-qt. Water),
sports drink, or salted food plus fluids
Heat Exhaustion
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Symptoms:
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Cause:
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heavy sweating, headache, light-headed,
nausea/vomiting, tingling sensations
Temperature 99-104 F
dehydration plus excessive salt depletion
Treatment:
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shaded environment; loosen clothing
If suspect early heat stroke, treat as such
oral fluids if can drink
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cold water, 0.1% salt solution, or 6% carbohydrate beverage
1-2 liters over 2-4 hours
EVAC
Heat Stroke
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Symptoms:
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elevated temperature plus central nervous system
disturbance
absence of sweating is a late finding
Can begin as heat exhaustion and progress
End-organ damage:
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brain damage, kidney failure, liver failure, blood
clotting abnormalities
related to duration of elevated temperature
Treatment of Heat Stroke
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ABC
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Unconscious patient may vomit and aspirate
Keep patent airway
IV: no more than 2L unless circulatory collapse
Lower the body temperature as fast as possible!
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All clothes off
Cool water with fanning...increase evaporation
Ice packs near groin or in the axilla
EVAC...open doors/windows in vehicle
keep cooling to temp 101-102 F.
Risk Factors for Heat Stroke

Dehydration
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Respiratory and GI illnesses most common
Alcohol use
Laxatives and diuretics
Medications
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Increase heat production and/or decrease heat loss
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Decrease sweating
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pseudoephedrine, thyroid hormone, cocaine
antihistamines (Benadryl), anti-nausea (Phenergan)
Supplements
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Ephedrine (MaHuang), caffeine
Pre-Hospital Care
Cooling is first priority
 Offer drink
 Drench with water
 Fan
 Massage large muscles
 Stop all measures if shivering occurs
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Guidance for Sports Drinks
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Cool water is usually the best rehydration fluid
Prolonged training and participation
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carbohydrates and electrolytes are also required for
optimal physical and mental performance
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meals and snacks plus water are best
When sports drinks are appropriate:
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duration > 6 hours, hot weather, if snacks/meals not
consumed
duration > 3 hours, strenuous exercise, if snacks, meals
not consumed
duration > 6 hours strenuous exercise, if total food intake
is significantly limited
Fluid Replacement Guidelines
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Easy Activity
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Moderate Activity
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3 QT water per 4 hours
Work:rest 40:20
Hard Activity
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1 QT water per 2 hours
Work:rest as needed
1 QT per hour
Work:rest 30:30 more rest with increased RF
Do not consume >12 QT per day.
Acclimatization
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Physiologic adaptation that occurs in response to
heat exposure in a natural environment
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Results:
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5 days for most
14 days required for 95% of population to have complete
acclimatization.
Can DE acclimatize as quickly
sweat at lower temperature
increased volume of sweat
decrease in amount to salt secreted in sweat
increased heat dissipation = lower core body
temperature
End result: Decreased risk for heat injury!
Fluid Replacement for Warm Weather
Heat
Category
WBGT
Index, °F
Easy Work
Work
/Rest
1
2
(Green)
3
(Yellow
4
(Red)
5
(Black)
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Moderate Work
Work
/Rest
78-81.9
82-84.9
NL
NL
Water
Intake,Qt/
h
½
½
NL
50/10 min
Water
Intake,
Qt/h
¾
¾
40/20 min
30/30 min
Water
Intake,
Qt/h
¾
1
85-87.9
NL
¾
40/20 min
¾
30/30 min
1
88-89.9
NL
¾
30/30 min
¾
20/40 min
1
> 90
50/10 min
1
20/40 min
1
10/50 min
1
Work
/Rest
The work/rest times and fluid replacement volumes will sustain performance and hydration for at least 4 hours of
work in the specified heat category. Individual water needs will vary ± ¼ quart/hour.
NL = no limit to work time per hour.
Rest means minimal physical activity (sitting or standing) and should be accomplished in shade if possible.
Caution: Hourly fluid intake should not exceed 1½ quarts.
 Daily fluid intake should not exceed 12 quarts.
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Hard Work
The End