ITLS Burns and Environmental Trauma 2 — Questions and Answers

Question 1: A patient rescued from a house fire has singed nasal hairs, hoarseness, and carbonaceous sputum. What should the ITLS provider anticipate?

Carbon monoxide poisoning only
Impending upper airway obstruction from thermal injury (Correct answer)
Third-degree burns to the lungs
Smoke inhalation without airway compromise

Correct answer: Impending upper airway obstruction from thermal injury

Singed nasal hairs, hoarseness, and carbonaceous sputum are classic signs of thermal inhalation injury, which causes progressive upper airway edema that can lead to complete obstruction within hours.

Thermal injury to the upper airway is a medical emergency in ITLS because the onset of obstruction is progressive and can be rapid. The supraglottic structures (epiglottis, arytenoids, vocal cords) swell dramatically when burned, potentially reducing the airway to a pinhole. Signs include singed facial/nasal hair, carbonaceous sputum, hoarseness or stridor, facial burns, and soot in the oropharynx. Early intubation is strongly recommended because once edema progresses, visualization for intubation becomes impossible and a surgical airway may be the only option. Hot gases typically do not reach the lower airways (the upper airway is an efficient heat exchanger), so third-degree lung burns are rare. Carbon monoxide poisoning and smoke inhalation are concurrent concerns but the immediate threat is airway loss.

Question 2: Using the Rule of Nines, what is the total body surface area (TBSA) burned for an adult with full-thickness burns to the entire right arm and anterior trunk?

18%
27% (Correct answer)
36%
45%

Correct answer: 27%

The entire right arm is 9% and the anterior trunk is 18%, totaling 27% TBSA. This exceeds the threshold for major burn center referral.

The Rule of Nines divides the adult body into regions of approximately 9% or multiples thereof: head and neck = 9%, each upper extremity = 9%, anterior trunk = 18%, posterior trunk = 18%, each lower extremity = 18%, and perineum = 1%. The right arm (9%) plus the anterior trunk (18%) equals 27% TBSA. Burns exceeding 20% TBSA in adults are considered major burns requiring fluid resuscitation and burn center referral. The Parkland formula (4 mL × kg × %TBSA burned) guides IV fluid replacement. For this patient, an 80 kg adult would need approximately 8,640 mL of lactated Ringer's in the first 24 hours, with half given in the first 8 hours from time of burn. Accurate TBSA calculation is critical because overestimation leads to fluid overload and underestimation leads to inadequate resuscitation.

Question 3: What is the correct initial fluid resuscitation strategy for a patient with 40% TBSA burns according to the Parkland formula?

Normal saline at a maintenance rate
Lactated Ringer's: 4 mL × body weight (kg) × %TBSA, half in first 8 hours (Correct answer)
Colloid solution bolus of 500 mL
D5W at 250 mL per hour

Correct answer: Lactated Ringer's: 4 mL × body weight (kg) × %TBSA, half in first 8 hours

The Parkland formula calculates total crystalloid needs as 4 mL × kg × %TBSA burned, with half the calculated volume infused in the first 8 hours from the time of burn and the remainder over the following 16 hours.

The Parkland (Baxter) formula is the standard for burn fluid resuscitation: 4 mL × weight (kg) × %TBSA = total volume of lactated Ringer's for the first 24 hours. Half is given in the first 8 hours (from time of burn, not from time of IV start), and the second half over the remaining 16 hours. For a 70 kg patient with 40% burns: 4 × 70 × 40 = 11,200 mL total; 5,600 mL in the first 8 hours (700 mL/hr) and 5,600 mL over 16 hours (350 mL/hr). Lactated Ringer's is preferred over normal saline to avoid hyperchloremic acidosis. Colloids are not used in the first 24 hours. D5W lacks the electrolytes needed for volume replacement. Urine output (0.5-1 mL/kg/hr in adults) is the best indicator of adequate resuscitation and should be used to titrate fluid rates.

Question 4: A patient presents with a circumferential full-thickness burn to the right lower leg. Several hours later, the foot becomes pale, cool, and pulseless. What complication has developed?

Deep vein thrombosis
Compartment syndrome from burn eschar (Correct answer)
Arterial embolism
Peripheral neuropathy from the burn

Correct answer: Compartment syndrome from burn eschar

Circumferential full-thickness burns create a rigid, non-elastic eschar that acts like a tourniquet as underlying tissue swells, causing compartment syndrome with vascular compromise.

Full-thickness (third-degree) burns destroy the dermis entirely, creating a leathery, inelastic eschar. When this eschar encircles an extremity, the post-burn tissue edema has nowhere to expand. Pressure builds within the fascial compartments, eventually exceeding arterial perfusion pressure. Signs progress from pain out of proportion, paresthesias, and pallor to pulselessness—the 5 P's of compartment syndrome. Treatment is an escharotomy: longitudinal incisions through the eschar (not the fascia) on the medial and lateral aspects to release constriction. This is performed at the burn center. Circumferential chest burns can similarly restrict ventilation and require escharotomy. DVT takes days to develop. Arterial embolism is unrelated to the burn mechanism. Peripheral neuropathy occurs in the chronic phase.

Question 5: What is the most dangerous type of electrical burn injury and why?

Low-voltage AC because it causes more skin damage
High-voltage DC because it produces the most heat externally
High-voltage AC because it causes internal tissue destruction disproportionate to visible burns (Correct answer)
Lightning strike because it always causes cardiac arrest

Correct answer: High-voltage AC because it causes internal tissue destruction disproportionate to visible burns

High-voltage AC causes the most dangerous electrical burns because current travels through the body along blood vessels and nerves, destroying deep tissues while skin burns may appear minimal.

Electrical burns are classified as an iceberg injury—what is visible on the surface represents only a fraction of the damage. High-voltage (>1000V) alternating current follows the path of least resistance through the body, primarily along blood vessels, nerves, and muscles. This causes massive internal tissue necrosis, rhabdomyolysis (muscle breakdown releasing myoglobin), hyperkalemia from cellular destruction, and potential renal failure from myoglobin precipitation. Entry and exit wounds may be small but the corridor of destruction between them can involve entire limbs. Cardiac dysrhythmias (ventricular fibrillation with AC, asystole with DC) are immediate threats. ITLS teaches that all significant electrical burn patients need cardiac monitoring, aggressive IV fluids to flush myoglobin, and burn center evaluation. Lightning injuries, while dramatic, often cause superficial burns with cardiac arrest being the primary lethal mechanism.

Question 6: A hiker is found with a core temperature of 30°C (86°F). He is conscious but confused and shivering has stopped. How should the ITLS provider manage this patient?

Encourage the patient to exercise to generate heat
Aggressively warm with hot water bottles placed directly on skin
Handle gently, remove wet clothing, insulate, and transport to a hospital for rewarming (Correct answer)
Administer warm IV fluids at maximum rate and vigorously rub extremities

Correct answer: Handle gently, remove wet clothing, insulate, and transport to a hospital for rewarming

Moderate hypothermia (30-34°C) requires gentle handling to avoid triggering ventricular fibrillation, passive rewarming with insulation, and hospital transport for controlled active rewarming.

At 30°C, the patient is moderately hypothermic. Cessation of shivering indicates the body has exhausted its primary heat-generating mechanism—a concerning sign of worsening hypothermia. The myocardium becomes extremely irritable below 32°C, and rough handling, jostling, or vigorous rewarming can trigger ventricular fibrillation. ITLS management includes: gentle handling (no unnecessary movement), removing wet clothing and insulating with dry blankets/sleeping bags, preventing further heat loss (vapor barrier), and transporting to a facility capable of active core rewarming (warm IV fluids, forced warm air, peritoneal lavage in severe cases). Exercise is contraindicated as peripheral vasodilation drops cold blood into the core (afterdrop). Direct heat application can burn insensate skin and cause peripheral vasodilation. Vigorous rubbing of extremities worsens afterdrop and can damage cold-injured tissue.

ITLS Burns and Environmental Trauma 2

A patient rescued from a house fire has singed nasal hairs, hoarseness, and carbonaceous sputum.
What should the ITLS provider anticipate?