Environmental Emergencies

Question 1

Low Voltage Injury

High Voltage Injury

Answer 1

Low voltage AC: muscular tetany causing pt to continue to grab the electrical source

-Tend to cause v-fib

High voltage AC or DC: single violent muscular contraction which throws the victim from the source

• increased risk blunt trauma and blast injuries
• Tend to cause asystole and respiratory arrest

Question 2

Frequent Electrocution Injuries

Answer 2

Neurological impairment

Pupil dysfunction

Ruptured eardrums

Assess extremities for compartment syndrome

Rhabdomyolysis with pigment-induced renal failure

Question 3

Lightening Strikes

Answer 3

DC current

Immediate cardiac arrest and respiratory arrest (medulla depolarized)

Ruptured TMs

Fern-like erythematous skin marking

Question 4

Fresh Water vs Salt Water Drowning

Answer 4

Fresh: transient hemodilution - blood cells swell and burst

-can get significant hemolysis w/ large volume aspirated

Salt: Saltwater in lungs draws blood out of bloodstream into lungs

-Sodium builds up in alveoli - stops oxygen from reaching blood

Both fresh and salt water wash out surfactant

Question 5

Drowning End Organ Effects

Answer 5

Pulmonary: noncardiogenic edema, ARDS

Neurologic: hypoxemia and ischemia, cerebral edema with increased ICP

CV: Arrhythmias 2nd to hypothermia and hypoxemia; Sinus brady and fibrillation MC

Acid-base/Electrolytes: Metabolic and/or respiratory acidosis

Question 6

Management of Drowning Patients with GCS >=13

Answer 6

O2

Observe for 4-6 hours

DC if pulmonary exam and SaO2 on room air remain normal

Question 7

Management of Drowning Patients with GCS <13

Answer 7

O2 +/- ventilatory support

CXR

Labs: ABGs, CBC, CMP - dilution hyponatremia = seizures

-PT/PTT, UA, CK, urine myoglobin, UA tox screen

Question 8

Hypothermia Classifications

Answer 8

Mild: 90-95 F

Moderate: 82-90 F

Severe: <82 F

Hypothermia = core temp <35C (95F)

Question 9

Hypothermia Pathophysiology

Answer 9

Heat generated by cellular metabolism in heart and liver

Heat loss by skin and lungs

• Evaporation
• Radiation
• Conduction
• Convection

Question 10

Mild Hypothermia Presentation

Answer 10

Tachypnea, tachycardia, hyperventilation

Ataxia, dysarthria, impaired judgement

Shivering

Cold diuresis

Question 11

Moderate Hypothermia Presentation

Answer 11

Reduced pulse and CO

Hypoventilation

A-fib, junctional bradycardia

CNS depression, hyporeflexia

Decreased renal blood flow

Loss of shivering, paradoxical undressing

Question 12

Severe Hypothermia Presentation

Answer 12

Pulmonary edema

Oliguria

Areflexia

Coma

HOTN, bradycardia

Ventricular arrhythmias, asystole

Question 13

EKG Indicating Hypothermia

Answer 13

J-waves (Osborne) with body temp 80F

New onset a-fib

Prolonged QRS

Prolonged QT

Question 14

Frostbite Classification

Answer 14

1st: central area pallor and anesthesia w/ edema surrounding (superficial)
2nd: Blister form w/ clear/milky fluid w/ edema and erythema w/in 24 hours
3rd: Blisters are deeper and hemorrhagic, progress to black eschar over several weeks
4th: extend to muscle and bone, involved complete tissue necrosis

Question 15

Frostbite Treatment

Answer 15

Rapid rewarming

Waterbath heated to 40-42 C - dry heat hard to regulate

Thawing usually completed 15-30 minutes

Apply bulky dressing, elevation, splinting

Consider tPA to prevent limb loss

Question 16

2 Types of Heat Exhaustion

Answer 16

Water depletion: inadequate volume replacement - working in hot environment

-Hypovolemia, can progress to heatstroke

Salt depletion: large volumes of thermal sweat are replaced with water without enough salt

-Hyponatremia, hypochloremia

Question 17

Heatstroke Pathophysiology

Answer 17

CNS dysfunction from cerebral edema: ataxia, irritability, confusion, bizarre/combative behavior

Peripheral vasodilation: functional hypovolemia w/ splanchnic and renal vasoconstriction for compensation

Prolonged severe heat stress: Splanchnic vasoconstriction fails, heated core blood increases ICP, Decreased mean arterial pressure

Question 18

Heatstroke Death

Answer 18

Vascular shock decreases blood flow to brain

Irregular pulse/heart attack

Kidney failure

Blood clots form throughout body

Question 19

Hyperthermia Treatment

Answer 19

Rapid cooling

Stop efforts once rectal temp <40C (104F) - continued cooling may cause hypothermia

Monitor for seizures, aspiration, HOTN, pulmonary edema

Tachyarrhythmias should resolve with cooling