Frostbite – Causes, Symptoms, Diagnosis, Treatment and Ongoing care

Basics

Description

  • A localized complication of exposure to cold, causing tissue to freeze, resulting in diminished blood flow to the affected part (especially hands, face, or feet)
  • System(s) affected: Endocrine/Metabolic; Skin/Exocrine
  • Synonym(s): Dermatitis congelationis; Frostnip; Environmental injuries

Epidemiology

  • Predominant age: All ages
  • Predominant sex: Male = Female

Risk Factors

  • Previous cold-related injury
  • Decreased caloric intake (<1,500 calories/day)
  • Dehydration or hypovolemia
  • Impaired cerebral function
  • Under the effects of alcohol or drug abuse
  • Underlying psychiatric disturbance
  • Ambient temperature ≤-17.8°C (0°F)
  • Smoker
  • Elderly
  • Lean body mass
  • Low level of fitness
  • Lack of proper clothing or shelter
  • Raynaud phenomenon
  • Constriction from excessively tight clothing (including too many layers of socks)
  • Vehicular failure leading to prolonged cold exposure

General Prevention

  • Dress in layers with appropriate cold-weather gear.
  • Avoid clothing that is too constricting.
  • Cover exposed areas and extremities appropriately.
  • Prepare properly for trips to cold climates.
  • Avoid alcohol.

Pathophysiology

  • Ice crystals form intracellularly.
  • Dehydration, enzymatic destruction, and ultimately cell death occur.
  • In severe cases, deep-tissue freezing may occur with damage to underlying blood vessels, muscles, and nerve tissue.

Etiology

  • Prolonged exposure to cold
  • Refreezing thawed extremities

Commonly Associated Conditions

Alcohol and/or drug abuse

Frostbite, Hypothermia, cold weather gear, blister formation, cold climates, environmental injuries, cold exposure, cerebral function, extremities,

Diagnosis

History

  • Throbbing pain
  • Paresthesia
  • Excessive sweating
  • Joint pain

Physical Exam

  • Feet, hands, and face most commonly affected
  • Injured area appears cold, hard, and white and is anesthetic to touch. It progresses to blotchy-red, swollen, and painful regions after rewarming.
  • 1st degree: Redness and edema without blister formation
  • 2nd degree: Redness, edema, and blister formation
  • 3rd degree: Same as above with addition of hemorrhagic vesicles
  • 4th degree: Necrosis and gangrene
  • Pallor
  • Loss of cutaneous sensation
  • Numbness
  • Limited movement of affected joints
  • Subcutaneous edema
  • Hyperemia
  • Blistering
  • Blue discoloration
  • Skin necrosis
  • Gangrene

Diagnostic Tests & Interpretation

ECG in hypothermia may show bradycardia, atrial fibrillation, atrial flutter, ventricular fibrillation, diffuse T-wave inversion, Osborn waves (upward-going “hump” following S wave in the RS–T segment)

Lab

  • May show signs of hemoconcentration such as elevated hemoglobin or high BUN/creatinine ratio
  • Liver function tests for decreased hepatic function

Imaging

  • Triple-phase bone scan can identify tissue viability at early stage and facilitate early debridement.
  • Other imaging techniques sometimes used include MRI/MRA, infrared thermography, angiography, digital plethysmography, and laser Doppler studies.

Pathological Findings

  • Ice crystallization in the intravascular extracellular space
  • Atrophy
  • Fibroblastic proliferation
  • Skin necrosis

Differential Diagnosis

  • Frostnip, a superficial cold injury that does not cause permanent damage
  • Chilblains (pernio), an inflammatory reaction to short-term cold, wet exposure without tissue freezing
  • Immersion syndrome (trench foot), inflammatory reaction to prolonged cold, wet exposure, typically socks or footwear

Treatment

Geriatric Considerations

  • Associated disease states increase mortality
  • Periarticular osteoporosis complicates
  • More prone to hypothermia

Pediatric Considerations

Loss of epithelial growth centers

Alert

Acidosis

Medication

First Line

  • tPA administered within 24 hours of injury may prevent damage from thrombosis and may reduce amputation rate (1,2)[C].
  • Tetanus toxoid
  • Penicillin G 500,000 units every 6 hours for 48–72 hours prophylactically (3)[B]
  • Ibuprofen 400 mg every 12 hours to inhibit prostaglandins (3)[C]
  • NSAIDs for mild-moderate pain. For severe pain, narcotic analgesia.
  • Precautions: tPA should not be used with history of recent bleeding, stroke, ulcer, etc.

Second Line

Vasodilators such as iloprost and pentoxifylline have been tried with some success (3)[C].

Additional Treatment

General Measures

  • If transport time will be short (1–2 hours at most), the risks posed by improper rewarming or refreezing outweigh the risks of delaying treatment for deep frostbite (4)[C].
  • If transport will be prolonged (more than 1–2 hours), frostbite will often thaw spontaneously. It is more important to prevent hypothermia than to rewarm frostbite rapidly in warm water. This does not mean that a frostbitten extremity should be kept in the cold to prevent spontaneous rewarming. Anticipate that frostbitten areas will rewarm as a consequence of keeping the patient warm and protect them from refreezing at all costs (4)[C].
  • Rapid rewarming (3)[B]:
    • Immerse frozen body part in warm water (37–39°C [99–102°F]) for 15–30 minutes or until thawing is complete.
    • Continue rewarming until a red/purple color appears and the affected part becomes pliable.
    • It is critical not to allow refreezing after thawing has occurred.
  • After rewarming, injured parts should be covered with nonadhesive dressings, splinted, and elevated.
  • Remove jewelry and clothing, if present, from the affected area.
  • Application of aloe vera every 6 hours
  • Sterile cotton between fingers or toes, if applicable, to prevent maceration
  • Keep the patient dry.
  • If conscious, give the patient warm fluids with high sugar content.
  • Prevent infection once treatment begins.
  • Institute ongoing whirlpool therapy for cleansing and debridement.
  • Prevent damage to other body parts.
  • Prohibit use of nicotine-containing products (including cigarettes) or other vasoconstrictive agents.
  • Maintenance: Gastric lavage, peritoneal dialysis, hemodialysis, and mediastinal lavage if needed (using warmed fluids)

Additional Therapies

  • Heated oxygen
  • Warm intravenous fluids via central venous pressure line

Surgery/Other Procedures

  • Urgent surgery rarely needed except fasciotomy for compartment syndrome (suspect if tissue swollen and compartment pressures greater than 37–40 mm Hg)
  • Surgical debridement as needed to remove necrotic tissue
  • Amputation should not be considered until it is definite that tissues are dead: May take ∼3 weeks to know whether the tissue is permanently injured

In-Patient Considerations

Initial Stabilization

  • Institute emergency measures for hypothermic patient without pulse or respiration. Such measures may include CPR and internal warming with warm intravenous fluids and warm oxygen (see topic Hypothermia).
  • Prevent refreezing.
  • It may be necessary to keep the frostbitten part frozen until the patient can be transported to a care facility. Prolonged freezing is preferable to warming and refreezing (5)[C].
  • Remove nonadherent wet clothing.
  • Treat for hypothermia.
  • Treat for pain:
    • NSAIDs and/or narcotics if needed
  • Do not rub areas to warm them; increased tissue damage may occur (1)[C].
  • Do not allow patient with frostbitten feet to walk except when the life of the patient or rescuer is in danger (4)[C].

Admission Criteria

Hospitalization generally recommended (2)

Ongoing Care

Follow-Up Recommendations

Outpatient or inpatient, depending on severity:

  • As tolerated; protect injured body parts
  • Initiate physical therapy once healing progresses sufficiently.

Patient Monitoring

  • Preferably electronic probe for temperature monitoring (rectal or vascular)
  • Follow-up for physical therapy progress, infection, other complications

Diet

  • As tolerated
  • Warm oral fluids

Patient Education

  • Refer to local library for information.
  • Provide education on:
    • Exposure protection
    • Early signs and symptoms of frostbite

Prognosis

  • Anesthesia and bullae may occur.
  • The affected areas will heal or mummify without surgery; the process may take 6–12 months for healing.
  • Patient may be sensitive to cold and experience burning and tingling.
  • Cyanotic nonblanching skin and blisters with dark fluid suggest worse prognosis (5)[C].

Complications

  • Hyperglycemia
  • Acidosis
  • Refractory arrhythmias
  • Tissue loss: Distal parts of an extremity may undergo spontaneous amputation
  • Gangrene
  • Death

References

1. Bruen KJ, Ballard JR, Morris SE, et al. Reduction of the incidence of amputation in frostbite injury with thrombolytic therapy. Arch Surg.2007;142:546–51; discussion 551–3.

2. Jurkovich GJ. Environmental cold-induced injury. Surg Clin North Am.2007;87:247–67, viii.

3. Imray C, Grieve A, Dhillon S, Caudwell Xtreme Everest Research Group et al. Cold damage to the extremities: frostbite and non-freezing cold injuries.Postgrad Med J. 2009;85:481–8.

4. State of Alaska Cold Injury Guideline: Alaska Multi-level 2003 Version. http://www.chems.alaska.gov/EMS/documents/AKColdInj2005.pdf.

5. Biem J, Koehncke N, Classen D, et al. Out of the cold: management of hypothermia and frostbite. CMAJ. 2003;168:305–11.

Additional Reading

Cappaert TA, Stone JA, Castellani JW, et al. National Athletic Trainers’ Association position statement: environmental cold injuries. J Athl Train.2008;43:640–58.

Murphy JV, Banwell PE, Roberts AH, et al. Frostbite: pathogenesis and treatment. J Trauma. 2000;48:171–8.

Reamy BV. Frostbite: review and current concepts. J Am Board Fam Pract.1998;11:34–40.

Twomey JA, Peltier GL, Zera RT. An open-label study to evaluate the safety and efficacy of tissue plasminogen activator in treatment of severe frostbite.J Trauma. 2005;59:1350–4; discussion 1354–5.

See Also (Topic, Algorithm, Electronic Media Element)

Hypothermia

Algorithm: Hypothermia

Codes

ICD9

  • 991.0 Frostbite of face
  • 991.1 Frostbite of hand
  • 991.2 Frostbite of foot
  • 991.3 Frostbite of other and unspecified sites

Snomed

  • 370977006 Frostbite (disorder)
  • 86018005 Frostbite of face (disorder)
  • 4763005 Frostbite of hand (disorder)
  • 35195001 Frostbite of foot (disorder)

Clinical Pearls

  • Frostbite is considered a tetanus-prone injury. Treat as any injury involving tissue destruction.
  • Avoid rewarming en route to the hospital if there is a chance of refreezing. Avoid burns to affected areas, which may be numb and insensitive to heat.

Jean-Paul Marat

Many tips are based on recent research, while others were known in ancient times. But they have all been proven to be effective. So keep this website close at hand and make the advice it offers a part of your daily life.

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