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Wednesday, August 19, 2009

Burns

Burns

Description

Burn injuries represent an acute disruption of the skin.

Etiology

Burns can be classified into six categories:

  • Scald = hot liquids, grease, or steam
  • Contact = hot or cold surfaces
  • Thermal = fire or flames
  • Radiation burns
  • Chemical burns
  • Electrical burns

Diagnosis

Signs and Symptoms

  • Most burns will have external signs of integumentary damage.
  • Inhalation injury:
    • Facial burns
    • Carbonaceous sputum
    • Pharyngeal injection
    • Wheezing
    • Hoarseness
    • Singed nasal hair
  • Electrical burns may have minimal external findings.

History

  • Information from emergency medical services (EMS), family, friends, or witnesses may be required.
  • Medical history, surgical history, medications, allergies, social history, tetanus immunization status
  • Carbon monoxide poisoning with exposure to combustion
  • Cyanide poisoning from burning wool, silk, nylon, and polyurethane found in furniture and paper

Physical Exam

  • Focus on airway, breathing first, then head-to-toe secondary survey for concurrent injuries.
  • Evaluate face and oropharynx for signs of inhalation injury.
  • Assess need for immobilization of cervical spine.
  • Eye examination for corneal burns
  • Determine severity of partial- and full-thickness burns by assessing size and depth of burn:
    • Estimate surface area involved.

Pediatric Considerations

Specific patterns of injury may indicate nonaccidental injury (stockinglike or glovelike appearance of wounds, cigarette burns, etc.)

Essential Workup

The severity of the burn should be assessed by determining the size and depth.

Size

  • Reported as percent involvement of total body surface area (TBSA) in one of three ways:
  • 1. Rule of nines:
    • TBSA of body parts is estimated by multiples of 9%; applies to adults only.
    • Adult estimates of percentage of TBSA:
      • Head and neck: 9
      • Arms: right, 9; left, 9
      • Legs: right, 18; left, 18
      • Trunk: front, 18; back, 18
      • Perineum, palms: 1
    • In infants and children, the head contributes more to the percentage of TBSA and legs contribute less.
    • Infants/children:
      • Head and neck: 18
      • Arms: right, 9; left, 9
      • Legs: right, 14; left, 14
      • Trunk: front, 18; back, 18
  • 2. Lund and Browder chart, divides body into areas and assigns percentage of BSA based on age
  • 3. Palm surface area, patient's palm is approximately 1% of TBSA:
    • Estimate size in terms of number of patient's palms that cover burn.
    • Helpful in assessing smaller, scattered burns

Depth

  • Superficial or first-degree burns (epidermis only): local erythema and pain only, no blisters; healing occurs in several days
  • Partial-thickness or second-degree burns (epidermis and dermis): divided into superficial partial-thickness and deep partial-thickness burns:
    • Superficial partial-thickness: epidermis and superficial dermis:
      • Skin is red, moist, painful, good capillary refill, develop blisters
      • Heals in 14-21 days
    • Deep partial-thickness: epidermis and deep dermis:
      • Skin may be blistered, with dermis white to yellow; absent capillary refill, and pain sensation
      • Heals via epithelialization within 3-12 weeks
  • Full-thickness or third-degree burns (epidermis and dermis, extends into subcutaneous tissue):
    • Skin is charred, leathery and pale, no blisters.
    • Sensation absent
    • Lesions will not heal spontaneously; needs surgical repair and skin grafting.
    • Full-thickness burns with damage to underlying muscle or fourth-degree burns:
    • Full-thickness plus involvement of underlying fascia, muscle, bone, and other tissues
    • Requires extensive debridement
    • Resultant disability

Tests

Lab

  • For severe burns, obtain CBC, serum electrolytes, glucose, BUN, creatinine, and PT/PTT, type and cross-match, pregnancy test (female)
  • Blood gas with carbon monoxide level for closed space or inhalation exposures
  • Cyanide level if suspected

Imaging

  • Chest radiograph
  • Fiber optic bronchoscopy to assess inhalation injury

Differential Diagnosis

  • Electrical injury
  • Chemical injury
  • Associated trauma or intoxication

Treatment

Pre Hospital

  • Stop the burning process, remove smoldering clothes/jewelry.
  • Establish patent airway; frequent reassessment:
    • Intubate early for signs of respiratory distress.
  • Initiate early IV fluid therapy.
  • Relieve pain.
  • Protect the wound with clean sheets.
  • Transport to burn center (for major burns) if transport time shorter than 30 minutes.
  • Immobilize spine if decreased sensorium or trauma.

Initial Stabilization

  • Airway control paramount:
    • Early intubation for patients with signs of upper airway injury, significant nasolabial burns, or circumferential neck burns
  • IV access, supplemental 100% oxygen, monitor, pulse oximetry
  • Evaluation for concurrent injuries
  • Provide adequate analgesia.

ED Treatment

Fluid Resuscitation: Partial and Full-thickness Burns (>20% TBSA)

  • Parkland formula: 4 mL of lactated Ringer solution or normal saline (NS) per kilogram per percentage of BSA burned IV; one half of this total is given in the first 8 hours and the remaining half over the next 16 hours:
    • Example: 70-kg patient with a 40% TBSA burn requires 4 mL × 70 kg × 40% = 11,200 mL over 24 hours, with 5,600 mL over first 8 hours or 700 mL/h.
  • For large burns, >20% TBSA, IV fluid therapy should be guided by invasive hemodynamic monitoring or urine output; maintain urine output of 0.5 to 1.0 mL/kg/h for adults and 1.0–1.5 mL/kg/h for children.

Escharotomy

  • Circumferential burn eschar may lead to neurovascular compromise:
    • Monitor pulses; may need Doppler flow probe.
    • Elevate burned extremity.
    • If circulation is compromised, escharotomy incisions on extremities should be made medially and laterally along the long axis of the limb just to the subcutaneous layer through the entire length of the burn eschar.
  • A circumferential burn of the chest wall may prevent adequate ventilation unless escharotomy is performed:
    • Make longitudinal incisions at anterior axillary line from the second rib to the level of the twelfth rib; connect with two transverse incisions across the chest.

Wound Care

  • Cover the wounds with sterile moist saline dressings.
  • If disposition is delayed, cleanse with sterile saline or poloxamer 188 product (e.g., Shur-Clens), debride blisters except those on palms or soles, and apply topical antibacterial agent (e.g., silver sulfadiazine, bacitracin, or mafenide acetate).
  • Do not delay transfer to burn unit for wound care.
  • Prophylactic antibiotics not indicated

Outpatient Management of Minor Burns

  • Sterile technique for cleansing and debridement
  • Remove loose, necrotic skin; debride broken, tense, or infected blisters.
  • Topical antibacterial agents: (e.g., silver sulfadiazine, bacitracin, mafenide acetate) recommended in deep partial-thickness or full-thickness burns only
  • Three-layer burn dressings should keep the wound moist and absorb exudate:
    • Inner layer should be nonadherent porous mesh gauze saturated with a non-petroleum-based lubricant, or use a mild ointment (e.g., bacitracin or Polysporin) under a nonadherent porous gauze.
    • The next layer should be fluffed coarse-mesh gauze.
    • The outer wrap should keep the dressing in place without constricting.
    • Dressings should be changed at least daily.
  • Silver wound dressings (Silverlon and Acticoat):
    • Thin coating of metallic silver applied to knitted fabric backing
    • Requires dressing to remain moist
    • May leave on for up to 3 days

Pediatric Considerations

  • Parkland formula underestimates fluid requirements in children; the Galveston formula may be used instead: 5,000 mL/m2 BSA burned plus 2,000 mL/m2.
  • TBSA of 5% dextrose in lactated Ringer solution IV over the first 24 hours, half in the first 8 hours and the other half over the next 16 hours
  • Consider nonaccidental trauma, particularly with burns on the back of hands or feet, buttocks, the perineum, and the legs.
  • Avoid hypothermia:
    • Children have greater BSA/mass ratio and lose heat more rapidly.
  • Avoid hypoglycemia:
    • Children are more prone to hypoglycemia owing to limited glycogen stores.

Pregnancy Considerations

  • Significant morbidity to mother and child
  • Fluid requirements may exceed estimations.
  • Fetal monitoring and early obstetric consultation recommended

Medication (Drugs)

  • Bacitracin ointment: Apply to wound one-four times per day.
  • Mafenide (Sulfamylon) acetate cream: Apply to wound one or two times per day.
  • Morphine: 0.1-0.2 mg/kg titrated to effect for pain control after shock
  • Silverlon and Acticoat: Cut sheet to size of burn; moisten with sterile water.
  • Silver sulfadiazine cream: Apply to wound one or two times per day.
  • Tetanus toxoid or immunoglobulin: 0.5 mL IM; 250 U IM once along with toxoid

Follow-Up

Disposition

Admission Criteria

N/A

Injuries Requiring Admission

  • Partial-thickness burns of noncritical areas (not the eyes, ears, face, hands, feet, or perineum) involving 10-20% of BSA in adults (older than 10 years and younger than 50 years)
  • Partial-thickness burns of noncritical areas involving 5-10% of BSA in children younger than 10 years
  • Suspicion of nonaccidental trauma
  • Patients unable to care for wounds in outpatient setting (e.g., homeless patients)

Injuries Requiring Transfer and Admission to a Burn Center

  • Partial-thickness and full-thickness burns involving ±10% of BSA in patients younger than 10 years or older than 50 years
  • Partial-thickness and full-thickness burns over >20% of BSA in any patient
  • Full-thickness burns involving >5% of BSA
  • Partial-thickness and full-thickness of face, hands, feet, genitalia, perineum, or major joints
  • Electrical burns, including lightning injury
  • Significant chemical injury
  • Inhalation injury
  • Burn injury in patients with pre-existing illness that could complicate management
  • Burn injury in patients with a concomitant trauma or social barrier

Discharge Criteria

Partial-thickness burns of <15%>

References

1. Committee on Trauma, American College of Surgeons. Guidelines for the operation of burn units. Resources for Optimal Care of the Injured Patient 1999.1998:55.

2. Holm C, et al. A clinical randomized study on the effects of invasive monitoring on burn resuscitation. Burns. 2004;30(8):798-807.

3. Kavanagh S, et al. Care of burn patients in the hospital. Burns. 2004;30(8):A2-6.

4. Schwartz LR. Thermal burns. In: Tintinalli JE, Kelen GD, Stapczynski JS. Emergency Medicine: A Comprehensive Study Guide. 6th ed. New York: McGraw-Hill, 2004:1220-1226.

5. Tompkins D, et al. Care of out patient burns. Burns. 2004;30(8):A7-9.

Codes

ICD9-CM

940.0-949.0

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