Chemical, Electrical, Lightning, and Radiation Burns Practice Questions

25 multiple-choice questions on Chemical, electrical, lightning, and radiation burns for paramedic and EMT students, from Chapter 33 (Burns). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

25 practice questions

1. A man knelt in wet concrete for several hours while working. His knees are now red and blistered. This injury is best managed as:

   1. A. A thermal burn from the curing heat
   2. B. An acid burn that needs a neutralizer
   3. C. An alkali burn that needs irrigation
   4. D. A simple friction blister needing nothing
   Show answer

   Answer: C. An alkali burn that needs irrigation

   Wet cement is strongly alkaline, and prolonged contact causes chemical burns that are often deeper than they look and may appear hours later. Remove wet clothing, irrigate thoroughly with water, and arrange burn evaluation. The mild heat of curing cement is not the cause, cement is an alkali rather than an acid, neutralizers are not used, and it is not a friction blister.

2. A 30-year-old splashed a strong acid on his legs at work. After ensuring scene safety, the mainstay of field treatment is:

   1. A. Copious water irrigation
   2. B. A neutralizing agent
   3. C. A dry sterile dressing
   4. D. Topical antibiotic ointment
   Show answer

   Answer: A. Copious water irrigation

   Large volumes of water dilute and remove the chemical. Neutralizers cause heat-producing reactions and delay irrigation, so they are not used in the field.

3. A bystander wants to pour vinegar on a coworker's alkali burn. You explain that a neutralizing agent is discouraged because it:

   1. A. Is not legal for EMS to carry
   2. B. Always makes the chemical more toxic
   3. C. Generates heat and delays irrigation
   4. D. Dries out the skin too quickly
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   Answer: C. Generates heat and delays irrigation

   Acid-base reactions are exothermic, adding a thermal injury to the chemical one. It also wastes time that should be spent flushing.

4. Compared with acid burns, alkali burns to the skin are generally:

   1. A. Deeper, because they liquefy tissue
   2. B. Shallower, because they coagulate tissue
   3. C. Less painful but heal faster
   4. D. Limited to the epidermis
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   Answer: A. Deeper, because they liquefy tissue

   Alkalis cause liquefaction necrosis that lets the chemical penetrate deeper over time. Acids cause coagulation necrosis that tends to limit spread.

5. You have irrigated a worker's alkali-splashed eyes for 20 minutes. If available, the best way to decide whether to keep irrigating is to:

   1. A. Stop as soon as the pain is somewhat less
   2. B. Look for redness to clear from the white
   3. C. Ask him whether he can see your fingers
   4. D. Check the eye's pH with test paper
   Show answer

   Answer: D. Check the eye's pH with test paper

   Irrigation continues until the conjunctival pH returns to near normal (about 7.0 to 7.5) when pH paper is available; alkali can keep leaching from tissue, so pain relief, redness, or vision alone do not show that irrigation is complete. Without pH paper, continue irrigating throughout transport.

6. A worker's shirt and watch are soaked with a corrosive liquid. Before and during irrigation of his skin, you should:

   1. A. Leave the clothing on to protect the skin
   2. B. Remove the soaked clothing and jewelry
   3. C. Irrigate over the clothing only, briefly
   4. D. Neutralize the liquid on the shirt first
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   Answer: B. Remove the soaked clothing and jewelry

   Contaminated clothing and jewelry hold the chemical against the skin and keep burning, so they must be removed (with proper PPE) while irrigation begins. Leaving them on or irrigating only through clothing prolongs contact. Neutralizing agents generate heat and delay irrigation.

7. A worker has particles of elemental sodium metal embedded in his skin. You should:

   1. A. Flush with large amounts of water
   2. B. Cover the area with mineral oil
   3. C. Scrub the area with soap and water
   4. D. Neutralize with sodium bicarbonate
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   Answer: B. Cover the area with mineral oil

   Sodium and potassium metals react violently with water, producing heat and hydrogen gas. They are covered with oil and removed at the hospital; this is the rare exception to flushing.

8. When responding to a chemical burn at an industrial site, your first priority is to:

   1. A. Ensure safety and wear proper PPE
   2. B. Start irrigation right away by hand
   3. C. Estimate the patient's TBSA
   4. D. Locate the plant's safety manager
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   Answer: A. Ensure safety and wear proper PPE

   An unprotected rescuer can become a second patient. Once protected, begin decontamination and irrigation.

9. In an electrical injury, tissue damage depends mostly on:

   1. A. The color and gauge of the wire
   2. B. The size of the surface burn
   3. C. Whether the patient was grounded
   4. D. The current flowing through it
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   Answer: D. The current flowing through it

   Current, determined by voltage and resistance, generates the heat that damages tissue. Grounding affects whether current flows, but the resulting current is what causes injury.

10. Which tissue offers the highest resistance to electric current?

    1. A. Nerves
    2. B. Blood vessels
    3. C. Bone
    4. D. Muscle
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    Answer: C. Bone

    Bone resists current and heats up, damaging the muscle around it. Nerves and blood vessels have the lowest resistance and carry current readily.

11. A 34-year-old lineman touched a high-voltage wire. He has a small charred wound on his hand and another on his foot. The surface wounds suggest:

    1. A. A minor injury, since wounds are small
    2. B. Possible extensive hidden damage
    3. C. Damage limited to the skin only
    4. D. That no current reached the heart
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    Answer: B. Possible extensive hidden damage

    Electrical burns are like an iceberg: small entry and exit wounds can hide deep muscle, nerve, and vessel injury along the current path. Wound size does not predict internal damage.

12. Low-voltage alternating current, as from a household outlet, is especially dangerous because it can:

    1. A. Throw the victim clear immediately
    2. B. Cause asystole from one massive pulse
    3. C. Cause tetany and VF
    4. D. Spare the heart when exposure is brief
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    Answer: C. Cause tetany and VF

    AC causes sustained muscle contraction, so the victim may be unable to let go, and it can trigger VF. High-voltage DC and lightning more often cause asystole and throw the victim. Even a brief household shock can cause VF if current crosses the heart.

13. A patient with a significant electrical injury should be placed on a cardiac monitor because:

    1. A. The monitor detects internal burns
    2. B. Pacing is needed in every case
    3. C. It reduces the risk of seizures
    4. D. Current can trigger dysrhythmias
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    Answer: D. Current can trigger dysrhythmias

    Current crossing the heart can cause immediate or, less often, delayed dysrhythmias and myocardial injury, so significant electrical injuries are monitored. The monitor does not detect internal burns. Pacing is not needed in every case; most patients have no rhythm disturbance. Monitoring does not reduce seizure risk.

14. Under ABA guidelines, a patient with a high-voltage electrical injury and dark red urine needs:

    1. A. More fluid, for urine of 1 to 1.5 mL/kg/hr
    2. B. Less fluid, to avoid pulmonary edema
    3. C. Fluid only for the visible TBSA at 2 mL/kg
    4. D. Oral fluids to dilute the dark urine
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    Answer: A. More fluid, for urine of 1 to 1.5 mL/kg/hr

    Myoglobin from muscle breakdown can cause kidney failure, so fluids start at about 4 mL/kg/%TBSA and are titrated to higher urine output until it clears. The visible TBSA underestimates the injury, so 2 mL/kg would be too little.

15. A 25-year-old got a brief shock from a household outlet. He had no loss of consciousness, has a tiny burn on one finger, and his 12-lead ECG is normal. Compared with a high-voltage injury, his risk of delayed dangerous dysrhythmias is:

    1. A. High
    2. B. The same
    3. C. Unknown
    4. D. Low
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    Answer: D. Low

    Studies show that asymptomatic patients after low-voltage household exposures with no loss of consciousness and a normal ECG rarely develop later dysrhythmias, so many protocols do not require prolonged monitoring for them. High-voltage injuries, loss of consciousness, abnormal ECG, or current crossing the chest carry higher risk and need monitoring.

16. An electrical injury patient who fell from a pole after contact should also be assessed for:

    1. A. Fractures and spinal injury
    2. B. Hypothermia from the wire
    3. C. Cyanide from burning insulation
    4. D. Hyperglycemia from the shock
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    Answer: A. Fractures and spinal injury

    Falls and violent tetanic contractions can cause fractures and spinal injuries. These associated injuries are easy to miss when attention is on the burn. Cyanide exposure needs smoke in an enclosed space, and neither hypothermia nor high blood sugar is an expected result of the shock.

17. At a lightning strike involving several victims, you should treat first the patients who:

    1. A. Are awake and complaining of pain
    2. B. Have the most visible skin burns
    3. C. Are in cardiac or respiratory arrest
    4. D. Have ringing in both of their ears
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    Answer: C. Are in cardiac or respiratory arrest

    Lightning victims who are moving and breathing usually survive, while those in arrest may recover with prompt CPR and ventilation. This reverse triage differs from usual mass-casualty triage.

18. Lightning commonly causes cardiac arrest by:

    1. A. Severe burns causing hypovolemic shock
    2. B. A massive DC shock causing asystole
    3. C. Coronary spasm causing a large MI
    4. D. Hyperkalemia from muscle breakdown
    Show answer

    Answer: B. A massive DC shock causing asystole

    Lightning acts like a huge DC shock that stops the heart. The heart may restart, but respiratory arrest can persist and cause a second hypoxic arrest, so ventilation is critical. Lightning burns are usually superficial, and coronary spasm or hyperkalemia from muscle breakdown is not the usual cause of the immediate arrest.

19. A hiker struck by lightning is awake but cannot move his legs, which are cold and mottled. This finding is most likely:

    1. A. A complete spinal cord transection
    2. B. Keraunoparalysis, often temporary
    3. C. Permanent nerve destruction
    4. D. A sign of malingering
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    Answer: B. Keraunoparalysis, often temporary

    Lightning can cause transient paralysis and vascular spasm that usually resolves within hours. Spinal injury from a fall must still be considered and the spine protected, but this pattern is classic for keraunoparalysis.

20. Fern-like reddish markings on the skin of a lightning victim are called Lichtenberg figures. They:

    1. A. Show full-thickness burns needing grafts
    2. B. Indicate the path of internal damage
    3. C. Mean the patient will develop VF
    4. D. Fade within hours and are not true burns
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    Answer: D. Fade within hours and are not true burns

    These marks come from electron showers on the skin and disappear within a day. They are diagnostic of lightning but do not reflect burn depth.

21. Your partner hesitates to touch a golfer who was just struck by lightning. You should tell her that she:

    1. A. Must wait 10 minutes for discharge
    2. B. Must wear insulated rubber gloves
    3. C. Is safe; his body holds no charge
    4. D. Will be shocked if he is wet
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    Answer: C. Is safe; his body holds no charge

    A lightning victim does not retain electrical charge. The real danger is further strikes, so move the patient to a safer location if storms continue.

22. A worker exposed to a sealed radioactive source has no radioactive material on his body or clothing. Regarding risk to the crew, he:

    1. A. Poses no radiation risk to providers
    2. B. Must be decontaminated before contact
    3. C. Emits radiation for several days
    4. D. Should be isolated for 24 hours
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    Answer: A. Poses no radiation risk to providers

    An irradiated patient is not radioactive. Only a contaminated patient, with radioactive material on the skin or clothing, needs decontamination.

23. The three principles that reduce a rescuer's radiation exposure are:

    1. A. Time, distance, and shielding
    2. B. Water, soap, and scrubbing
    3. C. Masks, gloves, and gowns
    4. D. Speed, lighting, and isolation
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    Answer: A. Time, distance, and shielding

    Minimizing time near the source, maximizing distance, and putting dense material between you and the source reduce dose. PPE helps prevent contamination but does not block gamma radiation.

24. A worker contaminated with radioactive dust is also hypotensive with a suspected pelvic fracture. The priority is to:

    1. A. Fully decontaminate before any care
    2. B. Treat life threats, then decon
    3. C. Survey him with a meter first
    4. D. Wash his hands and face before care
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    Answer: B. Treat life threats, then decon

    Radiation contamination rarely poses an immediate threat to life, so critical injuries come first. Removing clothing during care removes most contamination, and surveying or washing can wait until his shock and pelvic fracture are being managed.

25. Burns from radiation exposure differ from thermal burns in that they:

    1. A. Usually appear within an hour of exposure
    2. B. Heal faster than thermal burns
    3. C. Often appear days to weeks later
    4. D. Seldom progress to blistering
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    Answer: C. Often appear days to weeks later

    Radiation injures dividing cells, so redness, blistering, and ulceration may be delayed. Early vomiting after exposure is a better clue to a high whole-body dose. Skin injury often worsens over weeks and heals slowly, and moist desquamation with blistering is common at higher doses.