Burns

Background

Normal dermal anatomy.

Crossectional anatomy of burns, from left to right: first, second, and third degree.

• Any burns involving the dermis, superficial partial-thickness, or deeper allow for significant transdermal fluid losses
• Burns >60% BSA often associated with cardiac output depression unresponsive to fluids
• Inhalation injury is main cause of mortality
  • Half of patients admitted to burn centers develop ARDS

Jackson’s Burn Wound Model

Zone Name	Location	Tissue Damage	Change with Treatment
Coagulation	Inner	Dead	Not changed
Stasis	Middle	Dynamic penumbra	Target of burn care: good first aid and wound management can significantly reduce the need for skin grafting (otherwise it can turn into zone of coagulation, if not properly treated)
Hyperemia	Outer	Reactive inflammation	Will return to normal within hours of the injury regardless of care

Explains the dynamic nature of burn injuries and how assessment of size and depth at the time of injury can be different compared to 48 hours later

Pre-Hospital Care

• Cold running water for 20 minutes
  • Most effective if done within 3 hours.
  • No direct ice to wound
  • Do not apply creams or ointments
• Remove all burned/burning clothing, jewelry
  • Also remove rings or jewelry distal to injury due to anticipated swelling
• Assess for signs of inhalational injury
  • Hoarse voice, soot in nose or mouth, stridor, wheezing
  • Start humidified O2
  • Intubate if necessary (see below)
• Intravenous fluid (see below)

Clinical Features

Burn Thickness Chart

Thickness	Deepest Skin Structure Involved	Pain & Sensation	Appearance	Expected Course	Image
Superficial (first-degree)	Epidermis	Painful	Dry, erythema (no blisters) Blanching (intact cap refill)	Heals without scarring, 5-10 days
Superficial Partial (second-degree)	Superficial dermis (papillary region)	Painful	Wet, pale pink, blisters Blanching (intact cap refill)	Heals without scarring, <3 weeks
Deep Partial (second-degree)	Deep dermis (reticular region)	Decreased sensation	Pale white-yellow, blisters Does not blanch (absent cap refill)	Heals in 3-8 weeks Likely to scar if healing >3 weeks May require skin-graft if does not heal within 3 weeks
Full (third-degree)	Hypodermis (subcutaneous tissue)	Decreased sensation	White, leathery Does not blanch (absent cap refill)	Heals by contracture, >8 weeks Almost always requires skin grafting
Fourth-degree	Underlying fat, muscle and bone	Decreased sensation	Black; charred with eschar Does not blanch (absent cap refill)	Does not heal Frequently requires amputation

Differential Diagnosis

Burns

• Smoke inhalation injury (airway compromise)
• Chemical injury
  • Acrolein
  • Hydrochloric acid
  • Tuolene diisocyanate
  • Nitrogen dioxide
• Systemic chemical injury
  • Carbon monoxide toxicity
  • Cyanide toxicity
• Specific types of burns
  • Caustic burns
    • Airbag-related burns
    • Tar burn
    • Cement burn
  • Electrical injuries
    • Lightning Injuries
• Associated toxicities
  • Carbon monoxide toxicity
  • Cyanide toxicity
  • Hydrogen fluoride toxicity

Vesiculobullous rashes

Febrile

• Diffuse distribution
  • Varicella (chickenpox)
  • Smallpox
  • Monkeypox
  • Disseminated gonococcal disease
  • DIC
  • Purpural fulminans
• Localized distribution
  • Necrotizing fasciitis
  • Hand-foot-and-mouth disease

Afebrile

• Diffuse distribution
  • Bullous pemphigoid
  • Drug-Induced bullous disorders
  • Pemphigus vulgaris
  • Phytophotodermatitis
  • Erythema multiforme major
  • Bullous impetigo
• Localized distribution
  • Contact dermatitis
  • Herpes zoster (shingles)
  • Dyshidrotic eczema
  • Burn
  • Dermatitis herpetiformis
  • Erythema multiforme minor
  • Poison Oak, Ivy, Sumac dermatitis
  • Bullosis diabeticorum
  • Bullous impetigo
  • Folliculitis

Evaluation

Rule of Nines

Workup

• Carboxyhemoglobin level
• Carbon monoxide and cyanide levels
• VBG, CBC, chem, total CK
• CXR
• ECG
• Urinalysis (assess for myoglobinuria)
• Coagulation studies (severe burn patients can suffer from coagulopathies such as DIC)
• Lactate (higher lactate levels suggest increase mortality rate and inadequate resuscitation)
• Serial assessments for compartment syndrome

Diagnosis

• Normally a clinical diagnosis
  • See estimating body surface area

Management

• Consider empirically treating for cyanide toxicity especially if fire was in an enclosed place

Not Severe (Outpatient)

• Cold running water for 20 minutes if within 3 hours.
• Cleanse burn with mild soap and water or dilute antiseptic solution
• Debride wound as needed
• Consider a topical antimicrobial:
  • Bacitracin, neomycin, or mupirocin
  • AVOID Silver Sulfadiazine as it may interfere with partial thickness healing and offers no healing advantage (inhibits keratinocytes)
• Consider use of synthetic occlusive dressings (see burn dressings)
• Blisters
  • Leave blisters intact unless they cross a joint or if a large blisters precludes application of a dressing
  • Aspiration is preferred to deroofing
• Tetanus vaccine (if 2nd degree or higher)

Severe (Inpatient)

• IVF (see below)
• Analgesia
• Remove all rings, watches, jewelry, belts
• Local burn care (burn dressing)
  • Contact burn center BEFORE applying any antiseptic dressings
  • Small wound: moist saline-soaked dressing
  • Large wound: sterile drape
• Antibiotics
  • Administer in coordination with burn physician
  • Prophylactic antibiotics have been abandoned - debridement is paramount to prevent infection
  • Maintain glucose control to prevent infection
  • Core temperature is usually "reset" to 38-39°C, so fever in the absence of other symptoms of sepsis does not indicate infection
  • If septic, start broad spectrum antimicrobials - be sure to assess for need for antifungals in addition to antibiotics
• Nasogastric Tube
  • Consider if partial-thickness burn >20% BSA (ileus frequently occurs)
  • Definite NG tubes in burns > 30% in adults and 25% in children
• Early GI prophylaxis (PPI/H2 blocker)
  • evidence of stress ulceration even within hours after major burns
• Tetanus vaccine

Fluid Resuscitation

General

• The Parkland formula (4mL*kg × % TBSA of burns, not including superficial burns) and modified Brooke formula (2ml/kg/%TBSA) are the two most widely used resuscitation formulas.
  • There is general agreement that there is an increasing tendency to over-resuscitate during burn shock.
  • Resuscitation recommendations are only a guide; must titrate to patient's urine output, clear sensorium, and HR less than 110
  • Give least amount of fluid necessary to sustain organ perfusion (avoid "fluid creep")
  • Patients with inhalation injury and/or multi-system trauma may require more fluid.
• Goal directed therapy with Swan-Ganz catheters, inotropes, and fluid support have shown no superiority to standard clinical parameters, and have increased over-resuscitation and incidence of abdominal compartment syndrome (see below)

Indications based on Total Body Surface Area (TBSA) of Burn

• Definite IV: Adults > 20%, Peds > 15%
• Perhaps IV: Adults 15-20%, Peds 10-15%
• Oral adequate: Adults < 15%, Peds < 10%

Types of fluids

• Many burn centers prefer lactated ringers unless shock liver or hepatic failure suspected
• Colloids generally not used unless burns > 40% TBSA
• Do not use dextrose in adults (false UOP), but children should receive small amounts due to small glycogen stores

Fluid Quantity

• 2-4mL x weight (kg) x %TBSA (2nd and 3rd degree only) = mL NS (or LR) over 24hr
• Give 1/2 in first 8hr, remainder in next 16hr

Peds

• Give Parkland + maintenance fluid (2-4cc/kg x %BSA) if age < 5 yrs old
• Give 1/2 in first 8 hr, remainder in next 16 hr
• Can consider giving D5 1/2 NS if patient < 20 kg to prevent hypoglycemia

Goal UOP

• If UOP is greater than expected, consider glycosuria and reactive hyperglycemia as cause.
• Maintain urine output of 0.5-1 mL/kg/hr' urine in adults and 1-2 mL/kg/hr in children weighing < 30 kg
• If myoglobinuria seen, double expected UOP until urine grossly clears (consider mannitol diuresis)

Intubation Guidelines

• Full-thickness burns of the face or perioral region
• Circumferential neck burns
• Acute respiratory distress
• Progressive hoarseness or air hunger
• Respiratory depression
• Altered mental status
• Supraglottic edema and inflammation on bronchoscopy

Escharotomy Burn Indications

• Circumferential eschar with one of the following:
  • Circumferential torso - restricted ventilation
  • Circumferential extremities - vascular compromise
• Immediate escharotomy if compartment pressure > 30 mmHg
• Elevate limb and optimize fluid status

Special Cases

• In burns > 40% in adults and > 30% in children < 5 yo, consider colloids which reduce abdominal compartment syndrome
  • Consider replacing 25% of IVF with FFP, so that total IV rate is unaltered through the 24 hrs post-burn
  • In children, give 1/2 of total volume as FFP and 1/2 as LR throughout 24 hrs
  • For infants < 2 yrs with > 30%, use 5% dextrose in LRs with the FFP
• Burns > 50% or SEVERE metabolic acidosis may require 44 mEq of bicarb to each 1 L of LR in first 24 hrs, maintain bicarb > 18
• Vitamin C to reduce fluid volume requirements and prevent capillary leak
  • Consider infusion of 66 mg/kg/hr for 24 hours of Vitamin C infusion for > 30% TBSA
  • To be started within 6 hours of burn injury

Beyond 24 hrs

• 24-48 hrs - patients require ~1/2 total volume given in first 24 hrs; change LRs to D5,1/2NS; give FFP 2 units for every liter of crystalloid
• 48-72 hrs - no formula; take into account TBSA/depth of burns (open partial thickness loss > full thickness with thick eschar), re-mobilization of 3rd space fluid beginning at this time

Disposition

Outpatient Treatment

24-48hr follow-up

• Partial thickness <10% BSA, age 10–50y
• Partial thickness <5% BSA, age <10y or >50y
• Full thickness <2% in anyone
• No major burn characteristics present

Hospital admission

• Partial thickness 10-20% BSA 10-50 yrs old
• Partial thickness 5-10% BSA in <10 or > 50 yrs old
• Full thickness burns 2-5% BSA in anyone
• High voltage injury
• Circumferential burns of an extremity
• Burns complicated by suspected inhalation injury
• significant comorbidities
• No major burn characteristics present

Burn Center Transfer Criteria

• Partial thickness >20% BSA (10-50 years old)
• Partial thickness >10% BSA (<10 or > 50 yrs old)
• Full thickness >5% BSA (any age)
• Burns involving face, eyes, ears, genitalia, joints, hands, feet
• Burns with inhalation injury
• High voltage electrical burn
• Chemical burns
• Burns complicated by fracture or other trauma (in which burn is main cause of morbidity)
• Burns in high-risk patients

See Also

• Caustic burns
• Electrical Injuries
• Lightning Injuries
• Burn dressings
• Estimating body surface area
• Carbon monoxide toxicity
• Cyanide toxicity
• Hydrogen fluoride toxicity
• Escharotomy

External Links

• https://www.racgp.org.au/afp/2017/march/burns-dressings/