EMS 33: Environmental Emergencies

Heat loss mechanisms

Conduction, convection, evaporation, radiation, and respiration

Hypothermia

Core body temperature below 95°F (35°C) resulting in failure of normal temperature regulation

Mild hypothermia

Core temperature about 95–93°F; patient is alert, shivering, and has tachycardia and tachypnea

Moderate hypothermia

Core temperature about 93–86°F; shivering stops and mental status declines

Severe hypothermia

Core temperature below 86°F with lethargy, coma, and severe cardiovascular depression

Profound hypothermia

Core temperature below 80°F; patient may appear dead with severe bradycardia, dysrhythmias, or cardiac arrest

General assessment for hypothermia

Estimate body temperature by placing the back of your hand on the patient's abdomen

Risk factors for cold injury

Wet conditions, poor insulation, restricted circulation, fatigue, poor nutrition, alcohol or drug use, diabetes, cardiovascular disease, and extremes of age

Frostnip

Superficial freezing of the skin without deeper tissue injury, usually affecting the ears, nose, or fingers

Immersion foot

Cold injury caused by prolonged exposure of the feet to cold, wet conditions

Signs of frostnip or immersion foot

Pale cool skin, persistent blanching, wrinkled skin, and decreased sensation

Frostbite

Local cold injury in which tissues actually freeze

Signs of frostbite

Hard waxy skin, firm tissue, swelling, and blisters after rewarming

Gangrene

Death of tissue requiring surgical removal

Cold emergency priorities

Remove from the cold, assess severity, provide oxygen, prevent further heat loss, and transport promptly

Warm humidified oxygen

Helps warm hypothermic patients from the inside while improving oxygenation

Handling hypothermic patients

Move gently because rough handling may trigger ventricular fibrillation

Vital signs in moderate to severe hypothermia

Bradycardia and hypotension

Hypothermia thermometer

Special thermometer used to accurately measure low core body temperatures

Pulse oximetry in hypothermia

May be unreliable because of poor peripheral perfusion

Risk during rewarming

Cardiac dysrhythmias may develop

General treatment of hypothermia

Remove wet clothing, insulate with dry blankets, provide warm humidified oxygen, and transport

Treatment of mild hypothermia

Apply external heat packs to the groin, axillae, and neck

Treatment of moderate or severe hypothermia

Prevent additional heat loss, avoid active field rewarming, and transport promptly

Treatment of frostnip

Warm gently using body heat or another warm object

Treatment of immersion foot

Remove wet footwear and gradually rewarm the affected foot

Treatment of severe frostbite

Do not massage or apply dry heat; rewarm only if refreezing is impossible

Field rewarming of frostbite

Immerse in water at 102–104°F, apply dry sterile dressings, and leave blisters intact

Avoid in cold injuries

Do not massage frozen tissue, do not allow stimulants or food if seriously hypothermic, and do not rewarm if refreezing is possible

Hyperthermia

Core body temperature of 101°F or higher

Risk factors for heat illness

High temperature, high humidity, poor acclimatization, and strenuous exercise

Heat cramps

Painful muscle spasms caused by fluid and electrolyte loss after strenuous activity

Heat exhaustion

Heat illness caused primarily by dehydration and electrolyte loss

Signs of heat exhaustion

Dizziness, weakness, syncope, nausea, vomiting, headache, cool clammy skin, thirst, and usually normal body temperature

Heatstroke

Life-threatening failure of the body's temperature-regulating mechanisms

Causes of heatstroke

Strenuous exercise, hot humid environments, heat waves, or children left in hot vehicles

Signs of heatstroke

Hot dry flushed skin, altered mental status, seizures, hyperthermia, tachycardia, tachypnea, and absence of sweating

Assessment of heat emergencies

Look for altered mental status, confusion, nausea, vomiting, muscle cramps, and lack of sweating

Medication history in heat illness

Ask about poor fluid intake, diuretics, and other medications

Vital signs in hyperthermia

Tachycardia and tachypnea are common

Heat cramps treatment

Move to a cool area, loosen clothing, rest, replace fluids if alert, cool with mist, and give oxygen if indicated

Heatstroke treatment

Move to a cool environment, maximize air conditioning, remove clothing, aggressively cool with wet sheets and fanning, provide oxygen and ventilatory support, and check blood glucose

Drowning

Respiratory impairment caused by submersion or immersion in liquid

Laryngospasm

Protective spasm of the vocal cords triggered by water entering the airway

When to suspect spinal injury after drowning

Diving injuries, falls into water, unconsciousness, or neurologic complaints

Most common spinal injury in diving accidents

Cervical spine injury

Cold-water drowning

Continue resuscitation because hypothermia may protect the brain and other vital organs

Diving reflex

Cold-water reflex causing bradycardia and reduced oxygen consumption

Air embolism

Air bubbles entering the bloodstream after rapid ascent from diving

Decompression sickness (the bends)

Nitrogen bubbles forming in tissues and blood vessels after rapid ascent

Causes of decompression sickness

Rapid ascent, prolonged deep dives, or repeated dives in a short period

Complications of decompression sickness

Blood vessel obstruction, tissue ischemia, and severe joint or muscle pain

Timing of air embolism

Usually develops immediately after surfacing

Timing of decompression sickness

May take several hours after surfacing to appear

Assessment of diving emergencies

Determine dive depth, duration, symptom onset, previous dives, chest pain, dyspnea, paresthesias, and trauma

Treatment of air embolism or decompression sickness

Remove from the water, keep calm, administer high-flow oxygen, monitor breath sounds, and transport promptly

Causes of deterioration after drowning

Pulmonary injury, fluid shifts, cerebral hypoxia, and hypothermia

Dysbarism injuries

Illnesses caused by changes in surrounding atmospheric pressure

Altitude illness

Illness caused by reduced oxygen availability at high elevations

Acute mountain sickness (AMS)

Early altitude illness caused by ascending too high too quickly

Signs of acute mountain sickness

Headache, lightheadedness, fatigue, nausea, poor appetite, insomnia, exertional dyspnea, and facial swelling

High-altitude pulmonary edema (HAPE)

Fluid accumulation in the lungs caused by high altitude

Signs of HAPE

Shortness of breath, cough with pink frothy sputum, cyanosis, and tachycardia

High-altitude cerebral edema (HACE)

Severe brain swelling caused by high altitude

Signs of HACE

Severe headache, ataxia, vomiting, extreme fatigue, and loss of consciousness

Treatment of HAPE and HACE

Administer oxygen, descend to a lower altitude, provide positive-pressure ventilation if needed, and transport

Lightning injury

Electrical injury ranging from minor burns to cardiac or respiratory arrest