Shock, Sepsis & Multisystem · Topic 8 of 14

Burns & Inhalation Injury

Multisystem · burns

Burns & Inhalation Injury

Protect the airway early, size the burn by the rule of nines, start lactated Ringer's by formula, titrate to urine output, and treat carbon monoxide and cyanide.

Key numbers

Fluids: 2–4 mL/kg × %TBSA2–4 mL/kg × %TBSA

Suspected cyanide: hydroxocobalamin 5 g IV5 g IV over 15 min

Titrate fluid to urine output 0.5 mL/kg/hUOP 0.5 mL/kg/h

01 · CalculateFluids: 2–4 mL/kg × %TBSA

Start lactated Ringer's at 2–4 mL/kg × %TBSA over the first 24 hours from the burn, half in the first 8 hours: Parkland uses 4 mL/kg; the ABA burn-shock guideline (2024) recommends starting at 2.

02 · CalculateRule of nines for burn size

Estimate %TBSA in adults by the rule of nines (head 9, each arm 9, each leg 18, trunk front 18, back 18, perineum 1), counting only partial- and full-thickness burns; the whole hand ≈ 1%.

03 · DoIntubate early for airway burns or soot

Intubate early for threatened airway — posterior pharyngeal edema, airway soot, stridor, carbonaceous sputum, perioral burns, singed nasal hair, or confinement in a burning space — before edema makes intubation impossible.

Diagnosis & monitoring

Work-up

Titrate fluid to urine output 0.5 mL/kg/hThe formula is only a starting rate: adjust hourly to urine output of 0.5 mL/kg/h in adults (1 mL/kg/h in children under 30 kg) to avoid both under-resuscitation and fluid overload.

Do right now

In this order

First moves

Intubate early for airway burns or soot

→

Carbon monoxide: 100% oxygen, check COHb

→

Suspected cyanide: hydroxocobalamin 5 g IV5 g IV over 15 min

→

Fluids: 2–4 mL/kg × %TBSA2–4 mL/kg × %TBSA

→

Titrate fluid to urine output 0.5 mL/kg/hUOP 0.5 mL/kg/h

Why each step

Intubate early for airway burns or sootIntubate early for threatened airway — posterior pharyngeal edema, airway soot, stridor, carbonaceous sputum, perioral burns, singed nasal hair, or confinement in a burning space — before edema makes intubation impossible.

Carbon monoxide: 100% oxygen, check COHbGive 100% oxygen by nonrebreather to every smoke-inhalation patient and measure carboxyhemoglobin by CO-oximetry; pulse oximetry and ABG saturation read falsely normal. Oxygen cuts COHb half-life from about 4.5 to 1.5 hours.

Suspected cyanide: hydroxocobalamin 5 g IVSuspect cyanide when a fire victim is more obtunded than the COHb explains, hypotensive, or has lactic acidosis (lactate ≥ 10 mmol/L): give hydroxocobalamin 5 g IV over 15 minutes; repeat once if needed.

Fluids: 2–4 mL/kg × %TBSAStart lactated Ringer's at 2–4 mL/kg × %TBSA over the first 24 hours from the burn, half in the first 8 hours: Parkland uses 4 mL/kg; the ABA burn-shock guideline (2024) recommends starting at 2.

Management

Orders

Hyperbaric oxygen for severe CO poisoningConsider hyperbaric oxygen (with poison center input) for CO poisoning with loss of consciousness, altered mental status, cardiopulmonary complications or ongoing chest pain, COHb > 25%, or pregnancy at lower levels.

Escharotomy for constricting circumferential escharA circumferential eschar of the chest or neck can restrict ventilation and of a limb can cause ischemia: perform escharotomy, ideally with burn-center input; fasciotomy if compartment pressure exceeds 30 mmHg (mostly high-voltage electrical burns).

Chemical burns: brush powder, then irrigateRemove clothing, brush off dry chemical powders before wetting, then flush acids, alkalis and organic compounds with copious water for at least 20 minutes after no chemical appears to remain.

Albumin to limit resuscitation volumeConsider human albumin during burn resuscitation, especially for larger burns or rising fluid needs, to lower total volume and improve urine output; over-resuscitation causes abdominal and extremity compartment syndromes.

Red flags & don'ts

Avoid harm

High-voltage burns hide deep muscle damage complicationHigh-voltage (> 1000 V) electrical burns destroy muscle, nerve and vessels under minimal skin injury: get an ECG, check urine for myoglobin, and watch for rhabdomyolysis, AKI and compartment syndrome.

The rules

Know these

Burn center: full-thickness > 1%, partial > 5%Consult a burn center for full-thickness burns > 1% TBSA, partial-thickness > 5% TBSA, or burns of hands, face, feet or perineum; consider transfer for age < 2 or > 60 or poor home care.

No prophylactic systemic antibiotics; update tetanusDo not give prophylactic systemic antibiotics; use topical antimicrobials and give a tetanus booster if none in 5 years (tetanus immune globulin plus vaccine if the series is incomplete).

Deep partial-thickness or full-thickness?

Commonly confused

Depth	Part of the dermis
Appearance	Blisters (superficial); white-red mottled (deep)
Sensation	Painful (less so when deep)
Healing	1–2 weeks superficial; ≥ 2 weeks deep, with scarring

More detail

Reference

Show 7 reference facts

Excise eschar and graft deep partial- and full-thickness burns early, ideally within about 3 days, to prevent sepsis and shorten hospitalization.

Early burn infections are mostly streptococci and staphylococci; gram-negative bacteria dominate after 5–7 days. Fever and leukocytosis are common without infection and are unreliable signs of sepsis.

Monitor intra-abdominal (and intraocular) pressure selectively during large-volume burn resuscitation.

Draw carboxyhemoglobin before hydroxocobalamin when possible: its deep red color interferes with CO-oximetry and causes red urine (chromaturia) and skin discoloration.

Start early enteral nutrition for burns > 20% TBSA; replace calcium, magnesium, potassium and phosphate, and give IV opioids for pain.

Lower airway injury from smoke often appears 24 hours or more after exposure, with rising oxygen needs and falling lung compliance; steam can burn below the glottis.

Severe CO poisoning can cause delayed neuropsychiatric syndromes (cognitive deficits, parkinsonism, psychosis) days to weeks later.

Pearl

The formula only starts the drip — urine output of 0.5 mL/kg/h decides the rate from then on.

Sources · Merck Manual Professional — Burns (Sept 2024) · Merck Manual Professional — Smoke Inhalation · Merck Manual Professional — Carbon Monoxide Poisoning (Apr 2025) · Cartotto R et al. American Burn Association Clinical Practice Guidelines on Burn Shock Resuscitation. J Burn Care Res 2024;45(3):565–589 (abstract via Europe PMC) · Cyanokit (hydroxocobalamin for injection) prescribing information — DailyMed · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).