Home | Index | Next ENVIRONMENTAL EMERGENCIES
INTRODUCTION
Optimal patient care requires that the EMT-I understand that pathophysiology and principles of management of patients with bites and stings and environmental emergencies. The following
topics will be discussed during this lesson:
· Thermal Injuries (exposure to excessive heat and cold)
· Diving Emergencies
· Near-Drowning and Drowning
· Bites and Stings
LESSON OBJECTIVES
At the end of this lesson the participants will be able to:
1. Identify the different mechanisms of heat loss/transfer.
2. State the signs and symptoms associated with hypothermia.
3. Explain the differences between heat cramps, heat exhaustion, and heat stroke.
4. Describe the pathophysiology of a drowning victim.
5. Explain the pathophysiology of a near-drowning victim.
6. State the signs and symptoms of decompression sickness.
7. State the signs and symptoms of and air embolism.
8. Discuss the signs and symptoms of different bites and stings.
9. Discuss transportation decisions relative to environmental emergencies.
SKILLS
Patient assisted Epi-Pen
KEY VOCABULARY
The following terms will be used during this class:
· Allergic Reaction – hypersensitivity to a foreign substance
· Anaphylaxis – exaggerated, severe, allergic response that can be fatal
· Chilblains – exposed parts of the body become very cold but not frozen
· Drowning – death from submersion
· Envenomation – a bite or sting transferring venom to the victim
· Environmental Emergency – a medical condition caused or exacerbated by weather, terrain, atmospheric pressure, or other local factors
· Frostbite – the tissues are frozen
· Hypothermia – cooling of the body core temperature to <95°F (35° C)
· Near Drowning – a submersion victim survives 24 hours or more following removal from the water
· Severe Hypothermia – Cooling of the body core temperature to <90°F (32.2° C)
KEY CONCEPTS
The following section provides information and space for taking notes on the key concepts discussed by the instructor.
THERMAL EMERGENCIES
Mechanisms of heat loss/transfer (heat transfer is from higher temperature to lower)
·
Convection: transfer
of heat via air or liquid current ·
Conduction:
transfer of heat by direct
contact ·
Radiation:
transfer of heat to nearby
objects without physically
touching them ·
Evaporation:
heat loss that occurs as water evaporates from the skin
Hypothermia
Pathophysiology
| · Cooling of the body to core temperature of <95º F (35ºC)
· Severe Hypothermia <90º F (32.2ºC)
· Can occur at temperatures well above freezing as well as below |
Predisposing Factors
|
· Environment: exposure to extreme or prolonged cold
· Age: more common in the elderly and very young
· Medical Condition: patients with injuries or illnesses, such as shock, head injury, burns, generalized infections, injuries to the spinal cord, and diabetes are more prone to hypothermia
· Ingestion of drugs or poisons
|
Typical Settings
| · Submersion hypothermia: near drowning in cold water (<70°F) (similar type results from exposure to cold rain and high winds)
· Field hypothermia: occurs in previously healthy individuals such as hiker, skiers, and climbers
· Urban hypothermia: occurs in individuals with physical predisposition, disability or illness (newborns, burns, malnutrition, elderly, hypothyroidism, anemia, diabetes, CNS injury, arteriosclerosis) |
|
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Signs & Symptoms (varies with severity)
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· Uncontrolled Shivering · No Shivering (<90°F) (Potentially unreliable sign and may be altered by alcohol intoxication) · Apathy & drowsiness to disorientation · LOC decreases severely at 94°F · Coma at 85°F · Uncoordinated movements, slurred speech · Sluggish pupils · Depressed vital signs (bradycardia, bradypnea, hypotension) · Cardiopulmonary arrest
|
Field Treatment BLS Procedures: ·
Prevent further
heat loss ALS Procedures
Local Cold Injuries
Pathophysiology
|
Prolonged exposure to cold results in tissue damage directly related to the length and severity of the exposure. |
Factors that influence severity
|
· Length of exposure
· Temperature to which the body part was exposed
· Velocity of wind during exposure
|
Predisposing factors
|
· Poor or inadequate insulation from cold or wind · Impaired circulation from tight clothing or shoes · Medical condition: circulatory disease, fatigue, poor nutrition · Alcohol or drug ingestion, cigarette smoking
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Signs and Symptoms
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· Chilblains ~ Local redness and swelling · Frostnip ~ Pale spots on the skin · Frostbite ~ skin is white, yellow-white, or blue-white
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Field Management
|
BLS Procedures: · Prevent further exposure · Remove Jewelry · Remove wet clothing · Loosen constricting clothing · Cover the injured area with dry dressings · Handle gently · Protect from pressure or friction · Do not rub · Do not thaw if there is a chance of refreezing (will increase the damage) · Keep patient’s core temperature warm (blankets, warm fluid if alert) · Assist with ALS procedures if necessary |
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ALS Procedures: · Unless there are other injuries or complications, local cold injuries are BLS responses.
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HYPERTHERMIA
Heat Cramps
Pathophysiology
|
· Increased perspiration results in fluid and electrolyte loss · The electrolyte imbalance causes muscle cramping |
Predisposing factors
|
· Physical exertion while in the heat |
Signs and symptoms
|
· Muscle cramping of the extremities and abdomen · Nausea · Diaphoresis · Normal or slightly elevated temperature |
Field Management
|
BLS Procedures: · Oral Salt solutions (if fully awake) · Remove from the heat to a shady spot · Rest · Loosen Clothing |
Heat Exhaustion
Pathophysiology
|
· Decreased heat dissipation causes excessive fluid and electrolyte loss and dehydration. |
Predisposing factors
|
· Prolonged exposure to heat
· Poor acclimation
· Heart Disease |
Signs and Symptoms
|
· Intense thirst · Weakness, fatigue, dizziness, syncope · Weak thready, pulse · Tachycardia · Hypotension · Nausea and vomiting · Muscle cramps · Pallor · Diaphoresis · Headache · Dizziness · Elevated Temperature |
Field Management
|
BLS Procedures: · Remove to a cool place or shady spot and remove constricting clothing · High flow O2 by mask · Oral salty solutions if fully alert · Shock Position · Assist with ALS procedures
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ALS Procedures: · Venous access (large bore) · Monitor |
Heat Stroke
Pathophysiology
|
Total failure of the heat loss mechanism due to prolonged or intense heat |
Predisposing Factors
|
· Exposure to heat · Strenous activity in a hot environment · Age · Diabetes · Cardiovascular Disease · Medications (antidepressants, diuretics) · Obesity |
Signs and Symptoms
|
· Hot Flushed skin · No diaphoresis (the usual cooling mechanism has failed) · ALOC (confusion to coma) · Dilated pupils · Nausea and Vomiting · Hypotension/weak thready, pulse · Deep rapid breathing (may be Cheyne-stokes) · Temperature (usually >105° F) · Seizures |
Field Management
|
BLS Procedures: · Maintain and protect airway · High flow O2 by mask · Shock position if hypotensive (left lateral if normal B.P.) · Initiate cooling measures · Ice bags in axilla · Move to cool environment · Remove clothing · Cover with wet sheets · Assist with ALS procedures
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ALS Procedures: · Advance airway prn · Venous access · Monitor · Valium for active seizures · Glucometer if ALOC · D50 if hypoglycemic · Narcan if suspicious of narcotic overdose · Treat arrhythmias · Rapid transport
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WATER EMERGENCIES - Drowning
Pathophysiology
|
· Dry drowning – laryngospasm prevents aspiration of water into the lungs but results in asphyxia
· Wet drowning – aspiration occurs and results in hypoxia |
Precipitating factors
|
· ETOH · Fatigue · Poor parental supervision · Sudden illness (MI, seizures) · Head and spinal injury · Shallow H2O blackout |
Signs and symptoms
|
· Dyspnea · Tachypnea · Cyanosis · ALOC · Seizures · Apnea · Cardiopulmonary arrest |
Field management
|
BLS Procedures: · Always assume spinal injury · Maintain and protect airway · Treat hypothermia · High flow O2 by mask · Basic life support or rescue breathing if necessary · Treat other injuries · Assist with ALS procedures |
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ALS Procedures: · Advance airway prn · Venous access · Monitor · ALS medications ~ D50 if glucometer <80 ~ Narcan if indicated ~ Valium for seizures ~ Epinephrine if in cardiopulmonary arrest · Cardiac arrest medications as indicated |
| GOLDEN RULE: All near drowning victims must be transported due to the possibility of delayed complications. These patients can be taken to the most accessible receiving facility, unless trauma criteria/guidelines are met. |
DIVING EMERGENCIES
Decompression Sickness
Pathophysiology
|
· Nitrogen bubbles escape into the small blood vessels and tissue spaces, instead of being excreted normally through the lungs
· Boyles Law: the volume of gas is inversely proportional to the pressure applied to it (increased pressure = decreased volume)
· One atmosphere of pressure is exerted for every 33 feet descended
· Nitrogen bubble occurs with rapid ascent
|
Signs and Symptoms
|
· Many occur 1-48 hours following ascent (usually within 3 hours) · Symptoms vary: depend on the organ involved · Paresthesia · Muscle, joint or abdominal pain · Skin mottling, itch, rash · SOB, coughing, chest pain · ALOC · Visual disturbances · Seizures · Shock
|
Field Management
|
BLS Procedures · Maintain and protect airway · High flow O2 by mask · Left lateral Trendelenburg · Obtain dive records (log book or dive computer readings) · Assist with ALS procedures
|
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ALS Procedures · Advanced airway prn · Venous access · Monitor · Contact Base Station regarding possible transport to hyperbaric chamber · Medications ~ D50 if hypoglycemic ~ Narcan · Valium for seizures
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Air Embolism
Pathophysiology
|
|
Signs & Symptoms
|
· Usually occur 1-2 minutes after surfacing · ALOC · Loss of movement or sensation · SOB · Tension pneumothorax · Seizures · Subcutaneous emphysema · Shock · Chest Pain · Cardiopulmonary arrest
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Field management
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BLS Procedures: · Maintain and protect the airway · Left lateral Trendelenburg position · High flow O2 by mask · Assist with ALS procedures · Obtain dive record (log or computer)
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ALS Procedures: · Advanced airway prn · Venous access · Monitor · Contact Base Station regarding possible transport to hyperbaric chamber · Rapid transport · ALS medications ~ D50 if hypoglycemic ~ Narcan if indicated · Valium if seizures
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BITES AND STINGS
Marine Animal Bites
Pathophysiology
|
|
Stingrays, Sea Urchins, and Scorpion fish
Signs and symptoms
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· Intense pain · Swelling · Bleeding · Nausea, vomiting · Weakness · Sweating · Vertigo · Tachycardia · Cramps · Severe reactions may cause syncope, paralysis, and death
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Field management
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BLS Procedures:
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ALS Procedures: · Advanced airway prn · Venous access prn · Monitor prn · Treat other symptoms as indicated
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Jellyfish, Sea Anemones, Portugese Man-of-War
Signs and Symptoms
|
· Mild ~ Pain, paresthesia, whip like red rash · Moderate ~ Blistering, local edema, more pain · Severe reaction ~ Headache, lethargy, vertigo, ataxia, syncope, seizure, coma ~ Nausea, vomiting ~ Anaphylaxis ~ Dysrhythmias ~ Death
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Field management
|
BLS Procedures: · Maintain and protect airway · Rinse with sea water or saline (not fresh water) · Wash with rubbing alcohol to neutralize · Scrape to remove large tentacles or nematocysts · Reapply rubbing alcohol · O2 prn · Assist with ALS procedures
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ALS Procedures: · Advanced airway prn · Venous access prn · Monitor prn · Other treatment as indicated
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INSECT BITES AND STINGS
Hymenoptera Stings
Pathophysiology
|
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Signs and Symptoms
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· Localized pain · Redness · Swelling · Skin Weal
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Allergic Reaction
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· Localized pain, redness, swelling and skin weal · Itching · Flushing · Tachycardia · Hypotension · Bronchospasm · Stridor/Laryngeal edema · Facial swelling · Uvular swelling
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Field management – non-allergic reaction
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BLS Procedures:
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ALS Procedures: · Not required unless allergic reaction/anaphylaxis
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Field management – allergic reaction
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BLS Procedures: · High flow O2 by mask · Shock position · Patient assisted medication; EPI-pen if available and prescribed for that patient · Assist with ALS procedures
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ALS Procedures: · Advanced airway prn · Venous access (large bore) · Monitor · ALS medications · Epinephrine (1:1000) 0.3 mg. SQ · Benadryl 50 – 100 mg IVP or IM
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Field management – Anaphylaxis
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BLS Procedures: · High flow O2 by mask · Shock position · Assist with ALS procedures
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ALS Procedures · Advanced airway prn · Venous access (large bore) · Glucometer if indicated · Fluid challenge · Monitor · ALS medications ~ Epinephrine (1:10,000) 0.1 mg IVP ~ Benadryl 50 – 100 mg. IVP ~ Dopamine drip if fluid challenge does not increase B.P. ~ Albuterol 2.5 mg/ 3 ml. Normal Saline if wheezing
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SPIDER BITES
Brown Recluse
Pathophysiology
|
· Cytotoxic venom which causes local tissue destruction |
Signs and symptoms
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Field management
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BLS Procedures: · Supportive care · If emergency care sought within 24 hours, the outcome is favorable
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ALS Procedures: · Not usually required
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BLACK WIDOW
Pathophysiology
|
· Neurotoxin |
Signs and symptoms
|
· Localized pain and redness · Swelling · Progressive muscle spasms (back and abdomen) · Progressive spasm of all large muscle groups · Severe back, chest, and shoulder pain (upper extremity bite) · Severe abdominal pain · Nausea, vomiting · Sweating · Paralysis · Hypertension · ALOC
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Field management
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BLS procedures: · Reassure victim · Monitor BP · Observe for hypertensive crisis · Assist with ALS procedures
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ALS procedures: · Monitor · Venous access pr · Treat other symptoms as indicated
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Scorpion Stings
In North
America the sculptured or bark scorpion, found in the Southwest United
States and Mexico is the only one that is dangerous to humans. The scorpion
is nocturnal and favors wooded areas along the edges of desert washes.
The sculptured scorpion is small (2-7.5 cm.) and yellow to brown and
may have tail stripes.
Pathophysiology:
Si
Signs and symptoms
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Field management
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BLS procedures:
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ALS procedures · Advanced airway prn · Venous access
· Monitor · Supportive Care
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