Burns

In depth

The one-page summary above is what the PDF prints. These sections go further.

Burn shock and the systemic response

In Jackson's three zones, the central zone of coagulation is dead, the surrounding zone of stasis is ischemic but salvageable, and the outer zone of hyperemia recovers (Jeschke 2020). Hypoperfusion, edema, infection and drying can turn stasis into necrosis over 48–72 hours, so burns often look deeper on day 3, and under-resuscitation deepens them.

Above about 20% TBSA, permeability rises in burned and unburned tissue alike: plasma volume falls, cardiac output drops and systemic vascular resistance climbs (ABA 2024). Burned dermis also develops a strongly negative interstitial pressure that pulls fluid out of capillaries (Lund 1988, rats: −1 to about −30 mm Hg). The leak is fastest in the first hours and largely settles by about 24 hours, so every formula front-loads half the volume into the first 8 hours. Myocardial depression lasts about 24–48 hours (Jeschke 2020).

From about day 3 the flow phase takes over: catecholamines rise up to 50-fold, with cortisol and glucagon (Williams 2009), driving tachycardia, fever, high cardiac output, low SVR, insulin resistance and muscle wasting, so fever and tachycardia no longer prove infection. In children with burns over 30% TBSA the response was still measurable 3 years later (Jeschke 2011). Potassium runs high early from cell lysis; later, diuresis and anabolism bring low potassium and phosphate.

Burn depth and TBSA estimation

Depth decides healing and surgery; TBSA decides fluids and transfer, and only partial and full thickness burns count. Estimates made before burn center admission, even by experts, are consistently inaccurate (Jeschke 2020), often too high because erythema is counted; up to 70% of patients referred with overestimated burns went home within 48 hours (Dries 2020). Remap after cleansing and at 48–72 hours, when depth declares itself; a burn not expected to heal within about 3 weeks is usually excised and grafted, because hypertrophic scarring becomes likely.

• Palm: in adults the palm with fingers is about 0.8% of TBSA in men and 0.7% in women (Rossiter 1996), so the 1% rule slightly overcounts.
• Obesity and cachexia distort both the rule of nines and the hand rule (Jeschke 2020); centers differ on using actual or adjusted weight in fluid formulas.

Fluid resuscitation, fluid creep and compartment syndromes

ABA 2024 recommends considering a 2 mL/kg/%TBSA start in adults with burns of 20% or more; any formula sets only the first rate, and the clock runs from injury. Exam items subtract fluid already given and fit the rest of the first half into the hours left; Alaska 2021 starts the calculated rate without subtraction or catch-up, and Dries 2020 finishes the first half over the remaining hours.

Titrate hourly to urine output: 0.5 mL/kg/h (30–50 mL/h) in adults, 1 mL/kg/h in children under 30 kg (JTS 2025 accepts 0.5–1), and 75–100 mL/h with pigmenturia until the urine clears (JTS 2025; Alaska 2021 uses 1–2 mL/kg/h for electrical injury). JTS changes the rate by 20% when output stays outside target and reassesses over 2 hours, avoids boluses unless MAP is below 65, and adds vasopressin 0.04 units/min, then norepinephrine, for hypotension that persists despite resuscitation.

Engrav 2000 found that 58% of 50 adults received more than 4.3 mL/kg/%TBSA, against the 12% Baxter predicted: fluid creep. Causes include boluses, generous opioid dosing, overestimated TBSA, slow down-titration and answering oliguria from intra-abdominal hypertension with more fluid. Danger markers are the Ivy index (250 mL/kg in 24 h) and runaway resuscitation (6 mL/kg/%TBSA in 24 h). ABA 2024 recommends considering albumin in the first 24 h, more strongly in larger burns, and as rescue when resuscitation deteriorates, but prefers research settings for starts within the first 12 h; JTS 2025 starts 5% albumin from 8–12 h if the rate exceeds 1,500 mL/h or the projected volume nears 250 mL/kg.

ABA 2024 recommends selective bladder and eye pressure checks when the 24-h volume approaches 250 mL/kg or 6 mL/kg/%TBSA or ACS seems to be evolving, and IOP checks with deep periorbital burns or proptosis; JTS 2025 checks bladder pressure every 4 h in intubated patients past 200 mL/kg. Measure supine at end-expiration with the same instilled volume each time (WSACS: no more than 25 mL; JTS: 25–50 mL). ACS affects about 4–17% of severe burns, with about 75% mortality (Strang 2014).

Escharotomy cuts through eschar into fat along midmedial and midlateral lines and across involved joints; on the chest it runs down the anterior axillary lines, joined across the upper abdomen if needed (JTS 2025). It still hurts, so give sedation and opioids; watch for bleeding as perfusion returns and recheck pulses hourly for 12–24 hours.

Inhalation injury, airway, CO and cyanide

Inhalation injury has three parts: heat injury above the cords (the upper airway absorbs heat, except from steam), chemical injury below them from soot and toxic gases, with bronchorrhea, bronchospasm, casts and sloughing, and systemic poisoning by CO and cyanide. It raised fluid needs from 3.98 to 5.76 mL/kg/%TBSA in Navar 1985 and adds 17 to the revised Baux score (age + %TBSA + 17; Osler 2010). Bronchoscopy confirms and grades it; hypoxemia may be late (JTS 2025).

• Expect early intubation for GCS below 8, symptomatic inhalation injury, deep face or neck burns, or TBSA ≥40% (JTS 2025); supraglottic airways fail once edema forms.
• Tie the tube (8.0 or larger in adults) with cotton ties, never tape, and recheck its depth as facial edema changes.
• Ventilate lung-protectively with aggressive pulmonary toilet and bronchoscopy for casts. JTS 2025 gives nebulized heparin 5,000 units with albuterol every 4 h; a meta-analysis of nine mixed-design studies favored it (Lan 2020, mortality RR 0.75), but practice varies.

Electrical and chemical injuries

Current favors low-resistance nerves, vessels and muscle, while bone resists and heats, so muscle dies next to bone under normal-looking skin. Every patient gets an ECG; monitor at least 24 hours after loss of consciousness or with a new ECG abnormality, while low-voltage patients without cardiac disease, loss of consciousness or ECG changes need no monitoring (Arnoldo 2006); troponin and CK-MB do not stratify risk. After high-voltage injury, fluids start at 4 mL/kg/%TBSA (ABA consensus); JTS 2025 checks CK every 6 h, expects fasciotomy rather than escharotomy, and judges clearing pigmenturia by urine color, because dipstick heme stays positive longer. Follow up for delayed cataracts and neuropathy.

Chemical burns continue until the agent is removed: irrigate with large volumes of water for at least 20 minutes after it seems gone, and never neutralize, because the reaction releases heat. Alkalis (lye, wet cement, drain cleaners) liquefy tissue and penetrate deeper than acids, which coagulate; irrigate eyes until the conjunctival pH is normal.

Hydrofluoric acid's fluoride ion penetrates and binds calcium and magnesium; pain is immediate above 50% strength but may be delayed up to 8 h at 20–50% and 12–24 h below 20% (ATSDR). Apply 2.5% calcium gluconate gel; persistent pain is treated with subcutaneous 10% calcium gluconate (up to 0.5 mL/cm²) or intra-arterial calcium (10 mL of 10% in 40 mL D5W over 4 h). Watch calcium, magnesium, potassium and the QT. ATSDR admits fingertip and eye burns, and skin burns larger than a palm, to ICU for 24 h.

Hypermetabolism, nutrition and burn sepsis

Feeding is treatment: start enteral feeds within about 6–12 hours of injury (Datta 2022), continuous and high in carbohydrate and protein (Herndon 2004), postpyloric if needed so feeding continues through operations. Indirect calorimetry sets calories; the Curreri formula (25 kcal/kg + 40 kcal per %TBSA) overestimates. Protein is 1.5–2 g/kg/day in adults and 2–4 in children (Datta 2022).

• Keep the room at 28–32 °C (Datta 2022; Herndon 2004) so less energy goes to heat production.
• Propranolol titrated to a 20% fall in heart rate lowered energy expenditure and raised net muscle protein balance by 82% in children with burns over 40% (Herndon 2001).
• Oxandrolone 10 mg every 12 h cut adult length of stay from 43.3 to 31.6 days (Wolf 2006, 81 patients); monitor liver enzymes.
• Glutamine 0.5 g/kg/day did not shorten time to discharge or lower 6-month mortality (RE-ENERGIZE 2022, 1,209 patients).
• Glucose targets vary: many ICUs use 140–180 mg/dL, while Datta 2022 cites 90–140 for burns. JTS 2025 gives a PPI for burns over 20% against Curling ulcer.

Infection causes more than 60% of burn deaths (Jeschke 2020). Gram-positive organisms colonize first, then gram-negatives such as Pseudomonas and Acinetobacter, then fungi. Invasive wound infection shows as partial thickness converting to full thickness, dark or violaceous discoloration, rapid eschar separation, cellulitis at the margins or graft loss, and biopsy confirms it. Systemic antibiotics are not given prophylactically (JTS 2025); in suspected sepsis check lungs, lines and urine too, and dose antibiotics for augmented renal clearance.

Wound care, pain and daily nursing checks

Early excision and grafting removes the eschar that feeds infection and hypermetabolism; it shortens stay and, without inhalation injury, lowers mortality (Ong 2006), at the cost of more transfusion, and TRIBE (Palmieri 2017) supports a hemoglobin trigger of 7–8 g/dL. Split-thickness autograft goes on as sheets on the face and hands and meshed elsewhere; allograft, xenograft or dermal substitutes bridge until donor sites heal.

• Grafts: immobilize and prevent shear for about 3–5 days; hematoma, seroma, shear and infection cause graft loss.
• Donor sites hurt more than grafts and heal in about 10–14 days; leave the dressing intact unless infected.
• Position against contracture: neck extended without pillows, shoulders abducted about 90°, elbows and knees straight, hands splinted in the intrinsic-plus position, ankles at 90°; elevate burned limbs.

Burn pain is background, breakthrough and procedural, and dressing changes hurt most. Give opioids IV during resuscitation, since subcutaneous and IM absorption is unreliable, and expect doses to climb with tolerance. Add scheduled acetaminophen, ketamine for procedures, gabapentinoids for neuropathic pain and itch, and distraction such as virtual reality; use NSAIDs cautiously early (kidney, bleeding). Every shift, check by system:

• Neuro: pain, sedation and delirium scores.
• Respiratory: tube depth and ties, secretions, peak and plateau pressures.
• Circulation and renal: MAP, hourly urine and its color, Doppler pulses, bladder pressure when due.
• GI and metabolic: feeds at goal, distension, glucose, potassium, phosphate, weight.
• Skin: grafts, donor sites, splints and pressure points, line sites, temperature.

Children, referral and transfer

Children have more surface area per kilogram, thinner skin that burns deeper at lower temperatures, small glycogen stores and narrow airways: 1 mm of edema in a 4 mm infant trachea halves the radius and raises resistance 16-fold. Formula resuscitation starts at smaller burns (over 10% TBSA in JTS 2025, 15% in some protocols) at 3 mL/kg/%TBSA plus untitrated maintenance D5LR by the 4-2-1 rule; the dextrose cutoff is under 30 kg in ABA-based protocols, under 13 years in JTS. JTS checks electrolytes every 8 hours for the first 72 hours.

• Toxic shock syndrome can follow even small scalds in young children, usually 2–3 days after injury: fever, rash, diarrhea, irritability, then shock (Frame 1985; Childs 1999).
• Suspect abuse with immersion patterns, sparing of flexures, delay in seeking care or a history that does not fit development (RCPCH 2022), and report as required.
• Prevention teaching: water heaters at or below 49 °C (120 °F).

The ABA 2022 chart on the one-pager sorts patients into immediate consultation with transfer considered, or consultation alone. It added depth to the special-area rule and moved low-voltage injury to consultation, so items written against the older list may key different answers.

• Before transfer: secure the airway if edema could close it en route, suture large-bore lines (tape will not hold on burned skin), run LR at the calculated rate, insert a Foley, place a gastric tube in intubated patients, and settle the need for escharotomy before leaving (JTS 2025).
• Cover with clean dry sheets and keep warm: clean dry dressings are the only prehospital wound care needed (Dries 2020).
• Send the time of injury, weight, TBSA map, every fluid given, hourly urine output, COHb, tetanus status and drugs given.

Evidence and controversies

Unsettled: albumin lowers volumes and raises urine output, but its effect on edema complications and survival is unproven (ABA 2024; ABRUPT 2 is ongoing), and plasma is for research only. High-dose vitamin C (66 mg/kg/h) trades fluid savings for osmotic diuresis, a misleading urine output, possible oxalate nephropathy and falsely high readings on some glucose meters. ABA 2024 makes no recommendation on early CRRT or the first vasopressor, advises against transpulmonary thermodilution targets, and weakly supports computer decision support (Salinas 2011: less crystalloid, more hours on target).

Exam pearls

• Parkland: 4 mL × kg × %TBSA of LR, half in the first 8 h from the burn; ABA consensus starts adults at 2 mL, children 3, electrical 4.
• Count only partial and full thickness; palm with fingers about 1%; infant head 18%, each leg 14%.
• Urine targets: adults 0.5 mL/kg/h (30–50 mL/h), children under 30 kg 1 mL/kg/h, pigmenturia 75–100 mL/h; titrate the rate rather than bolus.
• Ivy index 250 mL/kg in 24 h; IAP ≥12 is IAH, >20 with new organ dysfunction is ACS.
• A normal SpO₂ does not exclude CO: send COHb by co-oximetry and give 100% O₂; hydroxocobalamin for suspected cyanide.
• Avoid succinylcholine after the first 24 hours until the burns heal: hyperkalemia.
• Mafenide causes metabolic acidosis and pain; silver sulfadiazine, transient leukopenia; silver nitrate, hyponatremia.
• Early hyperkalemia and hemoconcentration; later hypokalemia, hypophosphatemia and hypermetabolism that lasts months to years.
• ABA sepsis trigger: 3 of temperature, heart rate >110, tachypnea, platelets <100,000 after day 3, hyperglycemia or insulin resistance, feeding intolerance.