Environmental Emergencies/Trauma

Bends

Common name for decompression sickness

Conduction

Loss of heat from direct contact

Convection

Loss of heat from air movement

Radiation

Transfer of heat by radiant energy (i.e. heat gain from a fire)

Decompression sickness

Condition seen in divers that ascend too quickly; nitrogen bubbles form in blood vessels and other tissues

Diving reflex

Slowing of heart rate caused by submersion in cold water

Dysbarism injuries

Signs and symptoms caused by difference between surrounding atmospheric pressure and the total gas pressure in various tissues, fluids, and cavities of the body

Heat exhaustion

Significant fluid and electrolyte loss due to heavy sweating

Heatstroke

Severe hyperthermia; marked by warm, dry skin, severely altered LOC, often irreversible coma

Hyperthermia

Body temp 101+

Mild hypothermia

• Body temp

• Signs/symptoms

• Cardiorespiratory response

• LOC

• 95-93

• Shivering, foot stamping

• Constricted blood vessels, rapid breathing

• Withdrawn

Moderate hypothermia

Level 1:

• Body temp

• Signs/symptoms

• Cardiorespiratory response

• LOC

Level 2:

• Body temp

• Signs/symptoms

• Cardiorespiratory response

• LOC

Level 1:

• 92-89

• Loss of coordination, muscle stiffness

• Slowing respirations, slow pulse

• Confused, lethargic, sleepy

Level 2:

• 88-80

• Coma

• Weak pulse, dysrhythmias, very slow respirations

• Unresponsive

Severe hypothermia

• Body temp

• Signs/symptoms

• Cardiorespiratory response

• LOC

• Less than 80

• Apparent death

• Cardiac arrest

• Unresponsive

Reverse triage

Used in treating multiple victims of a lightning strike where those who are in respiratory and cardiac arrest are focused on first

Turgor

Ability of skin to resist deformation

Local cold injuries

Cold injuries confined to exposed parts of the body

What potential underlying factors should you investigate in a cold injury?

• Exposure to wet conditions

• Inadequate insulation

• Restricted circulation from tight clothing, shoes, or circulatory disease

• Fatigue

• Poor nutrition

• Alcohol or drug abuse

• Hypothermia

• Diabetes

• Cardiovascular disease

• Age

How long should you check for a pulse in an unresponsive patient with suspected severe hypothermia?

At least 60 seconds

Why should you be gentle when moving hypothermic patients?

Rough handling may cause a slow, weak heart to twitch or fibrilate

General management for mild hypothermia

• Goal: passive rewarming

• Move the patient to a warmer environment

• To prevent further damage to feet, do not allow patient to walk

• Remove wet clothing

• Place dry blankets over and under the patient

• Place heat packs or hot water bottles to groin, axillary, and cervical regions (not directly on skin)

• Turn heat on high in the ambulance

• Give patient warm, humidified oxygen

• Handle gently

• Do NOT massage extremities

• Do not allow patient to eat or use any stimulants (caffeine, tea, soda, tobacco); these are vasoconstrictors and can further impair circulation

General management for moderate to severe hypothermia

• Goal: prevent further heat loss

• Remove patient from cold environment

• Handle very gently

• Place in ambulance

• Remove wet clothing

• Cover patient with blankets

• Transport

General management of local cold injuries

• Frostnip

• Immersion foot

• Frostbite

• Frostnip

  • Passive rewarming through contact with something warmer (i.e. place hands in armpits)

• Immersion foot

  • Remove wet shoes/boots and socks

  • Rewarm foot gradually

  • Cover with dry, sterile dressing

• Frostbite

  • Remove jewelry

  • Cover injury loosely with dry, sterile dressing

  • Do not apply heat or rewarm the part

  • Do not allow patient to stand or walk on frostbitten part

  • If prompt hospital care is unavailable and med control instructs you to begin rewarming in field:

    • Warm water bath: immerse frostbitten part in water at temp of 104-105; stir water continuously

    • Keep part in water until it feels warm and sensation has returned (expect patient to feel extreme pain)

    • Dress area with dry, sterile bandages, placing them between injured fingers and toes

    • NEVER allow part to refreeze

High air temperatures reduce heat loss through:

Radiation

High humidity reduces heat loss through:

Evaporation

What should you suspect in a patient with sudden onset abdominal cramps that has been exercising vigorously in a hot environment?

Heat cramps

Signs and symptoms of heat exhaustion

• Dizziness, weakness, syncope

• Nausea, vomiting, headache

• Muscle cramping

• Onset while working hard in a hot, humid, or poorly ventilated area and sweating heavily

• Onset at rest in older and infant groups

• Cold, clammy, pale skin

• Dry tongue and thirst

• Normal vital signs, except pulse is often rapid and weak, and diastolic BP may be low

Explain how heatstroke progresses

1. Confusion or change in behavior

2. Patient becomes unresponsive quickly and may seize

3. Pulse is rapid and strong at first → pulse becomes weaker and BP falls

4. Respiratory rate increases

5. Patient no longer perspires (may be residual sweat on the skin)

When working a heat emergency, remember that the heat emergency may be a primary problem or it may be…?

Aggravating an existing medical or trauma condition

In a heat emergency, moist, pale, cool skin indicates?

Excessive fluid and salt loss

In a heat emergency, hot, dry skin indicates?

Body is unable to regulate core temperature

In a heat emergency, hot, moist skin indicates?

Body is unable to regulate core temperature

Classic signs and symptoms of a heat emergency

• Absence of perspiration

• Decreased LOC

• Muscle cramping

• Nausea and vomiting

Which kinds of patients may have difficulty tolerating exposure to heat?

• Infants

• Geriatrics

• Patients with inadequate oral intake

• Patients taking diuretics

• People who are unable to remove themselves from the hot environment (homeless populations, people who have gotten lost outdoors)

General management of heat cramps

Heat cramps:

• Move patient into shade

• Have patient rest cramping muscles

• Fluids + electrolytes by mouth

• Loosen tight clothing

• Spray with water and fan them

General management of heat exhaustion

• Move patient into cooler enviro (ambulance or shade)

• Remove excessive clothing, especially around head and neck

• Give high-flow O2 if indicated

• If altered LOC, check BGL

• Cool patient with misting and application of ice packs to trunk of patient’s body (cold water immersion if available, especially if patient temp is >104 or they have altered LOC)

• Give fluids by mouth (if fully alert) and watch for nausea

• Transport and consider ALS rendezvous if:

  • Symptoms do not improve in 30 mins

  • LOC decreases

  • Person is very young, very old, or has underlying medical conditions like diabetes or cardiovascular disease

In a patient with suspected heat stroke, what other causes might there be for decreased LOC?

• Alcohol

• TBI

• Low BGL

General management of heat stroke

• Move patient out of hot enviro and into ambulance

• Turn on AC

• Remove patient’s clothing

• Administer high flow O2 if indicated

• Cold water immersion if possible until temp is 101-102

• Spray with water and fan them

• Exclude other causes of altered LOC

• Rapid transport

Major risk factors for drowning

1. Alcohol

2. Seizure disorders

3. Geriatrics with cardiovascular disease

4. Unsupervised access to water

What type of heat loss occurs when submerged in water that is colder than your body temp?

Conduction

In a case of cold water drowning, how should you go about resuscitating the patient?

Resuscitate for up to 1 hour after submersion while simultaneously rewarming the patient

Areas prone to descent injuries

• Lungs

• Sinus cavities

• Middle ear

• Teeth

• Area of face surrounded by diving mask

Explain what can happen in the lungs and thoracic cavity during an ascent emergency + signs and symptoms

• Diver holding their breath during ascent

• Air inside lungs high → ascent = external pressure on chest decreases → air inside lungs expands rapidly → alveoli rupture

• Air enters pleural space → pneumothorax

• Air enters mediastinum (space containing heart and great vessels) → pneumomediastinum

• Air enters bloodstream → air embolism → prevents normal flow of blood in body

Signs and symptoms:

• Blotching

• Pink frothy sputum

• Severe pain in joints and abdomen

• Dyspnea, chest pain

• Dizziness, nausea/vomiting

• Dysphasia

• Cough

• Cyanosis

• Vision problems

• Paralysis/coma

• Irregular pulse and cardiac arrest

Ascent and decompression sickness often present similarly, except:

Ascent injuries usually apparent upon resurfacing, decompression sickness can take hours to develop

Common secondary conditions present in drowning/diving emergencies

• Hypothermia

• Pulmonary injury

• Fluid shifts in body

• Cerebral hypoxia

• Pneumothorax

• Air embolism

• Decompression sickness

What info is important to relay to ER staff in cases of drowning/diving injuries?

• How long patient was submerged

• Temp of water

• Clarity of water

• Possibility of cervical spine injury

• Dive profile, usually available on dive log

Breath-holding syncope

• Happens to swimmers who breathe in and out rapidly and deeply before entering water

• Increases level of O2, decreases level of CO2 → decreased stimulus to breathe → drowning

Acute mountain sickness

• Diminished O2 pressure at heights >5000ft → hypoxia

• Signs/symptoms:

  • Headache

  • Lightheadness

  • Fatigue

  • Loss of appetite

  • Nausea

  • Difficulty sleeping

  • SOB on exertion

  • Swollen face

• Treatment:

  • Descend and O2 if dyspneic

• Other possible causes:

  • Hypoglycemia

  • CO poisoning from things like camp stoves

High Altitude Pulmonary Edema (HAPE)

• Altitude >8000ft

• Fluid collects in lungs

• Signs/symptoms:

  • SOB

  • Cough with pink sputum

  • Cyanosis

  • Rapid pulse

High Altitude Cerebral Edema (HACE)

• Brain swelling

• Signs/symptoms

  • Severe, constant, throbbing headache

  • Ataxia

  • Extreme fatigue

  • Vomiting

  • Loss of consciousness

Mild vs moderate vs severe lightning injuries

Mild

• Loss of consciousness

• Amnesia

• Confusion

• Tingling

• Superficial burns

Moderate

• Seizures

• Respiratory arrest

• Dysrhythmias that spontaneously resolve

• Superficial burns

Severe

• Cardiopulmonary arrest

• Usually delay in resuscitation due to remote locations means these patients often do not survive

Management of lightning strikes

• Reverse triage

• Control severe bleeding

• Tetany → stabilize patient’s head → jaw-thrust to open airway

• If in respiratory arrest w/ a pulse → ventilate

• If in cardiac arrest → CPR and AED

• Manage other injuries (splint fractures, dress and bandage burns)