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

  • Respiration: loss of heat through water vapor
 

 

 

 

 

 


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)

 

 

Signs & Symptoms (varies with severity)

 

·                    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:

  • Check for pulse for up to 45 seconds

·        Prevent further heat loss

    • Protect from wind, insulate from ground
    • Remove wet clothing
    • Wrap in blankets
  • High flow oxygen by mask
  • Keep patient at rest
  • Treat gently
    • Do not rub or manipulate extremities
    • Cold skin easily injured
    • Myocardial irritability may cause VF
  • Assist with ALS Procedures

 

ALS Procedures

  • Advanced airway prn
  • Venous Access
    • Most hypothermic patients are dehydrated
    • Use caution when administering cold I.V. fluids
  • Monitor
  • ALS drugs are used sparingly
    • Medications are poorly metabolized until the patient is warmed
  • Bradycardia is a physiologic effect (does not need treatment)
  • Consider D50 and Narcan if ALOC
  • Do not pronounce dead until “warm and dead”
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

       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

 

 

Signs and Symptoms

 

·         Chilblains

                 ~ Local redness and swelling

·         Frostnip

                 ~ Pale spots on the skin

·         Frostbite

                 ~ skin is white, yellow-white, or blue-white

 

 

    

    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

 

 

 

ALS Procedures:

·         Unless there are other injuries or complications, local cold          injuries are BLS responses.

 

 

 

 

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

 

 

 

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

 

 

 

 

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

 

 

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

 

 

 

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)