CBM Burn Classification & Assessment 3 — Questions and Answers
Question 1: Which burn wound characteristic is associated with POOR prognosis for spontaneous healing without grafting?
- Superficial partial-thickness with intact hair follicles
- Depth extending beyond 3 weeks to re-epithelialize (Correct answer)
- Wound that blanches uniformly with pressure
- Blistering over less than 5% TBSA
Correct answer: Depth extending beyond 3 weeks to re-epithelialize
Burns that are unlikely to re-epithelialize within 3 weeks typically require skin grafting to prevent hypertrophic scarring and functional loss.
Question 2: When assessing burn severity, which factor contributes MOST to increasing mortality risk in elderly patients?
- Larger head-to-body ratio
- Thicker dermis reducing burn depth
- Diminished physiologic reserve and comorbidities (Correct answer)
- Higher pain tolerance masking depth assessment
Correct answer: Diminished physiologic reserve and comorbidities
Elderly patients have reduced physiologic reserve, pre-existing comorbidities, and impaired immune response, all of which significantly worsen burn outcomes.
Question 3: A firefighter sustains burns to the entire right arm and the anterior surface of the right leg. Using the Rule of Nines, what is the estimated TBSA?
- 13.5% (Correct answer)
- 18%
- 22.5%
- 27%
Correct answer: 13.5%
The entire arm equals 9% TBSA and the anterior leg equals 4.5% TBSA, totaling 13.5% according to the Rule of Nines.
Question 4: Which type of burn is MOST likely to cause systemic toxicity through transdermal absorption of the causative agent?
- Thermal contact burn
- Electrical arc flash burn
- Hydrofluoric acid chemical burn (Correct answer)
- Radiation burn
Correct answer: Hydrofluoric acid chemical burn
Hydrofluoric acid penetrates the skin and releases fluoride ions that bind calcium systemically, causing life-threatening hypocalcemia and cardiac dysrhythmias.
Question 5: In electrical burn assessment, why is surface wound size a poor predictor of injury severity?
- Electrical burns always involve less than 1% TBSA
- Current travels internally causing deep tissue necrosis not visible externally (Correct answer)
- Rule of Nines overestimates electrical burn depth
- Skin resistance is higher than internal tissues
Correct answer: Current travels internally causing deep tissue necrosis not visible externally
Electrical current travels through the body along the path of least resistance, causing extensive internal muscle and nerve injury disproportionate to the small entry and exit wounds.
Question 6: Which clinical sign is MOST useful in differentiating superficial partial-thickness from deep partial-thickness burns during initial assessment?
- Presence of blisters
- Response to pin-prick sensation test (Correct answer)
- Wound surface temperature
- Color of the wound bed
Correct answer: Response to pin-prick sensation test
Pin-prick sensation testing helps differentiate these depths; superficial partial-thickness burns retain pain sensation while deep partial-thickness burns have markedly reduced sensation.
Question 7: A chemical burn from an alkali agent tends to penetrate deeper than an acid burn of similar concentration because alkalis cause:
- Coagulative necrosis, which limits further penetration
- Liquefactive necrosis, which allows ongoing tissue penetration (Correct answer)
- Immediate protein precipitation halting depth progression
- Oxidative reactions that are self-limiting
Correct answer: Liquefactive necrosis, which allows ongoing tissue penetration
Alkalis cause liquefactive necrosis, which continuously breaks down tissue barriers, allowing deeper penetration compared to the self-limiting coagulative necrosis from acids.
CBM Burn Classification & Assessment 3
Which burn wound characteristic is associated with POOR prognosis for spontaneous healing without grafting?