Anesthesiology APPLIED Exam › Critical care, resuscitation and trauma

Burns

Critical care, resuscitation and trauma·~4 min read· Physician-reviewed✓ Sourced · 6

Stem

A 38-year-old man, 90 kg, is brought in two hours after escaping a house fire. He has partial- and full-thickness burns over 40% of his body surface, including the face and both arms. His voice is hoarse, his nasal hairs are singed, and he is coughing carbonaceous sputum. SpO2 reads 99% on a non-rebreather mask, his lactate is 11 mmol/L, and he is booked for escharotomies.

Question

How will you manage his airway, oxygenation and fluid resuscitation?

Ideal answer

HeadlineInhalation injury: hoarseness, singed hair and soot, and the swelling worsens with resuscitation. I intubate now, prepared for a difficult airway.

Video laryngoscope, smaller backup tubes, surgical kit, surgeon present, aiming for a tube large enough for bronchoscopy.
Succinylcholine is acceptable at two hours; the hyperkalemia risk comes after the acute phase, peaking at 7 to 10 days.¹
Ignore the 99%; co-oximetry gas, 100% oxygen, because carboxyhemoglobin reads as oxyhemoglobin.²
Hydroxocobalamin after that gas, because lactate above 10 in a fire victim suggests cyanide and the drug interferes with co-oximetry.³
Lactated Ringer's, 2 mL/kg per % burn: 7.2 L per 24 h, half by hour 8 post-burn, about 600 mL/h, less prehospital fluid;⁴^,5 urine 0.5–1 mL/kg/h, 45–90 mL/h.⁵

Breaking down the answer

Early intubation — airway edema peaks after resuscitation starts, so waiting turns an easy intubation into an impossible one; waiting for respiratory distress is the classic error.
Succinylcholine has a window — the label contraindicates it after the acute phase of major burns, with an undetermined duration.¹
Distrust the oximeter — carboxyhemoglobin absorbs light like oxyhemoglobin, so SpO2 is falsely high;² only co-oximetry gives the truth, and hydroxocobalamin then makes later co-oximetry inaccurate.³
Why 2, not 4 — the American Burn Association now starts at 2 mL/kg per percent to curb fluid creep;⁴ Parkland's 4 mL/kg would give 14.4 L. Formal resuscitation applies above 20% TBSA in adults and 10% in children.⁶
Fluid creep — over-resuscitation causes abdominal compartment syndrome, ARDS and multiorgan failure;⁶ albumin, considered from 12–24 hours, lowers the total and improves urine output.⁴^,5
Escharotomy needs heat and blood — I warm the room and fluids, because he loses heat through the wound, and have blood available.

Follow-up question

He returns on day 9 for excision and grafting. His potassium is 4.6 mmol/L, and the resident has drawn up succinylcholine for induction because the airway was easy last time. What do you say?

Follow-up answer

HeadlineDay 9 is the peak for succinylcholine hyperkalemia after a major burn, and cardiac arrest is the result.¹ I stop the resident before induction.

A normal baseline potassium does not protect him, because the risk comes from upregulated receptors. I explain why and switch to rocuronium for a rapid sequence if one is needed, with sugammadex available. I plan for large blood loss with excision: cross-matched blood, an arterial line, active warming. Had succinylcholine been given by mistake and peaked T waves appeared, I would give calcium, insulin and glucose at once. I reassess the plan at every return to the OR, since the risk period has no defined end.¹

Pitfalls that cost points

Starting the resuscitation clock at arrival rather than at the burn.
Counting superficial burns in the TBSA: only partial- and full-thickness burns count.⁶

Rapid-fire

Q: What is the rule of nines? A: Head and each arm 9%; front trunk, back trunk and each leg 18%; Lund and Browder is preferred in children.⁶

Q: What urine output do you target in a child? A: 1.0–1.5 mL/kg/h.⁶

Q: What changes in the pediatric formula? A: Many use 3 mL/kg per percent burn and add maintenance fluid because of hypoglycemia risk.⁶

Q: When does succinylcholine hyperkalemia peak after a burn? A: At 7 to 10 days after the injury.¹

Numbers to know

Item	Value
Starting rate	2 mL/kg per % TBSA (American Burn Association, 2023);⁴ half in first 8 h from burn (European Burn Association)⁵
This patient	7.2 L in 24 h; 3.6 L by hour 8 (Parkland 4 mL/kg: 14.4 L)
Formal resuscitation	More than 20% TBSA adults, 10% children⁶
Urine output	Adults 0.5–1,⁵ children 1.0–1.5 mL/kg/h⁶
Succinylcholine risk peak	7–10 days after injury¹
Lactate suggesting cyanide	More than 10 mmol/L³

Sources

1.Quelicin (succinylcholine chloride) prescribing information · Drugs.com (FDA label) · drugs.com
2.Pulse oximetry (keyword) · OpenAnesthesia · openanesthesia.org
3.Hydroxocobalamin for Suspected Cyanide Poisoning · Emergency Medicine (Case Studies in Toxicology), 2010 · cdn.mdedge.comLugassy DM, Nelson LS.
4.American Burn Association Clinical Practice Guidelines on Burn Shock Resuscitation · American Burn Association (Cartotto et al., J Burn Care Res 2024;45:565-589), 2024 · europepmc.orgAbstract read: adults with burns >=20% TBSA; initiate resuscitation at 2 mL/kg/%TBSA to reduce volumes; consider human albumin, especially in larger burns, to lower volumes and improve urine output; selective intra-abdominal and intraocular pressure monitoring; no recommendation on vitamin C, FFP, early CRRT or vasopressors.
5.Comparative Analysis of Recent Burn Guidelines Regarding Specific Aspects of Anesthesia and Intensive Care · European Burn Journal (MDPI), 2025 · europepmc.orgFull text, Table A3: ABA 2 mL/kg/%TBSA; EBA and DGV 2-4 mL/kg/%TBSA with half within the first 8 h; ABA, EBA, DGV and ISBI start formal resuscitation above 20% TBSA; ABA urine target 0.5-1.0 mL/kg/h; ABA: consider albumin at 12-24 h.
6.Parkland Formula (StatPearls) · StatPearls Publishing · dev2.statpearls.com

Facts on this page were checked against these sources on Nov 2, 2026. Guidelines change; confirm doses against current institutional protocols.