CBM CBM Inhalation Injury & Respiratory Management 2 — Questions and Answers
Question 1: Hydrogen cyanide (HCN) toxicity in burn patients most commonly results from combustion of which materials?
- Synthetic polymers such as polyurethane foam and nylon (Correct answer)
- Natural cotton and wool fabrics
- Untreated hardwoods
- Aluminum wiring
Correct answer: Synthetic polymers such as polyurethane foam and nylon
HCN is released when nitrogen-containing synthetic polymers like polyurethane, nylon, and acrylics combust in house fires.
Question 2: Which antidote is currently the preferred treatment for suspected cyanide poisoning in burn patients in the US?
- Hydroxocobalamin (Cyanokit) (Correct answer)
- Sodium thiosulfate alone
- Amyl nitrite inhalation
- Sodium nitrite IV
Correct answer: Hydroxocobalamin (Cyanokit)
Hydroxocobalamin directly binds cyanide to form cyanocobalamin and is preferred over nitrite-based regimens because it does not cause methemoglobinemia.
Question 3: Circumferential chest burns may require escharotomy primarily because of which respiratory complication?
- Inelastic eschar restricts chest wall excursion, reducing tidal volume (Correct answer)
- Eschar occludes the airway externally
- Burn-induced pneumothorax
- Eschar increases dead space ventilation
Correct answer: Inelastic eschar restricts chest wall excursion, reducing tidal volume
Rigid circumferential chest eschar limits thoracic expansion, severely decreasing tidal volume and causing respiratory failure.
Question 4: Bronchoscopy is indicated in inhalation injury patients primarily to accomplish which goal?
- Directly assess airway injury and clear carbonaceous debris and casts (Correct answer)
- Deliver topical antibiotics to the lower airway
- Measure airway pressures
- Determine the extent of alveolar damage
Correct answer: Directly assess airway injury and clear carbonaceous debris and casts
Fiberoptic bronchoscopy allows direct visualization of mucosal erythema, edema, carbonaceous deposits, and pseudo-membrane formation in the tracheobronchial tree.
Question 5: A burn patient develops progressive hypoxia with bilateral infiltrates on chest X-ray 24–48 hours after injury. Which complication is most likely?
- Acute Respiratory Distress Syndrome (ARDS) (Correct answer)
- Aspiration pneumonia
- Pulmonary embolism
- Congestive heart failure
Correct answer: Acute Respiratory Distress Syndrome (ARDS)
ARDS is a well-recognized sequela of major burns and inhalation injury, characterized by diffuse alveolar damage and hypoxemic respiratory failure.
Question 6: Nebulized heparin alternating with N-acetylcysteine (NAC) in inhalation injury patients is used to achieve which therapeutic effect?
- Prevent fibrin cast formation and reduce airway obstruction (Correct answer)
- Treat secondary bacterial pneumonia
- Reverse bronchospasm
- Reduce alveolar surface tension
Correct answer: Prevent fibrin cast formation and reduce airway obstruction
Nebulized heparin breaks down fibrin clots while NAC acts as a mucolytic, together preventing the obstructive bronchial casts that complicate severe inhalation injury.
CBM CBM Inhalation Injury & Respiratory Management 2
Hydrogen cyanide (HCN) toxicity in burn patients most commonly results from combustion of which materials?