Frostbite: Difference between revisions

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==Background==
==Background==
[[File:Windchill21.gif|thumb|Whid chill chart]]
*Results from the freezing of tissue
*Results from the freezing of tissue
*It is a disease of morbidity, not mortality
*It is a disease of morbidity, not mortality
*Risk correlated with temperature and wind speed
*Risk correlated with temperature and wind speed
**Risk is <5% when ambient temperature (includes wind chill) is > –15C (5F)
**Risk is <5% when ambient temperature (includes wind chill) is > –15°C (5°F)
**Most often occurs at ambient temp < –20C (–4F)
**Most often occurs at ambient temperature < –20°C (–4°F)
*Can develop w/in 2-3sec when metal surfaces that are at or below –15C (5F) are touched
*Wetness and humidity increase the risk (water has 25x thermal conductivity of air)
*Can develop within 2-3sec when metal surfaces that are at or below –15°C (5°F) are touched
*Most commonly affects distal part of extremities, face, nose, and ears
*Most commonly affects distal part of extremities, face, nose, and ears
*High-risk groups: outdoor workers, elderly, homeless, drug or alcohol abusers, psychiatric disease
*High-risk groups: outdoor workers, elderly, homeless, drug or alcohol abusers, psychiatric disease, high-altitude or cold-weather athletes, military personnel
*"Hunter's response" - prolonged repeated exposure to cold is protective


===Pathophysiology===
===Pathophysiology===
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#*Most severe and usually most distal
#*Most severe and usually most distal
#*Damage is irreversible
#*Damage is irreversible
#Zone of Hyperemia
#*Least severe and usually most proximal
#*Generally recovers w/o treatment in <10d
#Zone of Stasis
#Zone of Stasis
#*Middle zone characterized by severe, but possibly reversible, cell damage
#*Middle zone characterized by severe, but possibly reversible, cell damage
#*It is this zone for which treatment may have benefit
#*It is this zone for which treatment may have benefit
#Zone of Hyperemia
#*Least severe and usually most proximal
#*Generally recovers without treatment in <10d


==Clinical Features==
==Clinical Features==
===Classification===
===Classification===
*Visual determination of tissue viability is difficult in first few weeks
''Visual determination of tissue viability is difficult in first few weeks; classify early injuries as '''superficial''' or '''deep''' ''
*Classify early injuries as ''superficial'' or ''deep''
{| {{table}}
*'''First degree (frostnip)'''
| align="center" style="background:#f0f0f0;"|'''Degree'''
**Partial-skin freezing
| align="center" style="background:#f0f0f0;"|'''First (frostnip)'''
**Stinging and burning, followed by throbbing
| align="center" style="background:#f0f0f0;"|'''Second'''
**Numbness, erythema, swelling, dysesthesia, desquamation (days later)
| align="center" style="background:#f0f0f0;"|'''Third'''
**Minimal pain with rewarming
| align="center" style="background:#f0f0f0;"|'''Fourth'''
**Prognosis excellent
|-
*'''Second degree'''
| '''Pathophys'''||Partial-skin freezing||Full-thickness skin freezing||Tissue loss involving entire thickness of skin||Extension into subcutaneous tissues, muscle, bone, and tendon; little edema
**Full-thickness skin freezing
|-
**Numbness followed by aching and throbbing
| '''Symptoms'''||Stinging and burning, followed by throbbing||Numbness followed by aching and throbbing||Extremity feels like a "block of wood" followed by burning, throbbing, shooting pains||Deep, aching joint pain
**Substantial edema over 4-6 hours
|-
**Skin blisters form w/in 6-24 hours
| '''Course''' ||Numbness, erythema, swelling, dysesthesia, desquamation (days later)||
***Desquamate and form hard black eschars over several days
Substantial edema over 4-6 hours; skin blisters form within 6-24 hours; Desquamate and form hard black eschars over several days
**Mild to Moderate pain with rewarming
||Hemorrhagic blisters form and are associated with skin necrosis and blue-gray discoloration||Skin is mottled with nonblanching cyanosis and formation of deep, dry, black eschar
**Prognosis is good
|-
*'''Third degree'''
| '''Pain with rewarming'''||Minimal||Mild to moderate||Severe||None
**Tissue loss involving entire thickness of skin
|-
**Extremity feels like a "block of wood" followed by burning, throbbing, shooting pains
| '''Prognosis'''||Excellent||Good||Often poor||Extremely poor
**Hemorrhagic blisters form and are associated with skin necrosis and blue-gray discoloration
|-
**Severe pain with rewarming
| '''Image'''||[[File:PMC2873703 eplasty10e35 fig1.png|center|200px]]||[[File:PMC3785582 aps-40-510-g001.png|center|200px]]||[[File:PMC5286755 IJD-62-59-g009.png|center|200px]]||[[File:PMC4106255 eplasty14ic20 fig1.png|center|175px]]
**Prognosis is often poor
|}
*'''Fourth degree'''
**Extension into subcutaneous tissues, muscle, bone, and tendon; little edema
**Deep, aching joint pain
**Skin is mottled w/ nonblanching cyanosis and formation of deep, dry, black eschar
**Painless during rewarming
**Prognosis is extremely poor


==Differential Diagnosis==
==Differential Diagnosis==
{{Cold injuries DDX}}
{{Cold injuries DDX}}


==Diagnosis==
==Evaluation==
[[File:PMC4789935 10.1177 1941738116630542-fig2.png|thumb|Second degree frostbite progression.]]
*Usually clinical
*Usually clinical


==Management==
==Management==
*If hypothermia present, must rewarm to a core temperature of at least 35°C before treating frostbite<ref>Handford C, Thomas O, Imray CHE. Frostbite. Emerg Med Clin N Am. 2017;35(2):281–299.</ref>
*Remove all wet or constrictive clothing
*Thawing
*Thawing
**Do NOT attempt until the risk of refreezing is eliminated
**Do NOT attempt until the risk of refreezing is eliminated
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**Rapid rewarming is the core of therapy and should be initiated as soon as possible
**Rapid rewarming is the core of therapy and should be initiated as soon as possible
***Extremities
***Extremities
****Place in water with temperature of 40-42C (104-107.6)
****Place in water with temperature of 37 to 39°C (98.6 to 102.2°F)
****Approximately 20-30min, until extremity is pliable and erythematous
****Approximately 20-30min, until extremity is pliable and erythematous
****OR consider 38-40°C in whirlpool bath with antibacterial soap<ref>Crawford-Mechem C et al. Frostbite Treatment & Management. Aug 25, 2015. http://emedicine.medscape.com/article/926249-treatment#showall</ref>
****'''OR''' consider 38-40°C in whirlpool bath with antibacterial soap<ref>Crawford-Mechem C et al. Frostbite Treatment & Management. Aug 25, 2015. http://emedicine.medscape.com/article/926249-treatment#showall</ref>
***Face
***Face
****Apply moistened compresses soaked in warm water
****Apply moistened compresses soaked in warm water
*Analgesia
*[[Analgesia]]
**Rewarming is very painful
**Rewarming is very painful
**Provide parenteral opiates
**Provide parenteral [[opioids]]
*Local wound care
*Local wound care
**Apply topical aloe vera cream q6hr (interrupts arachidonic acid cascade)
**Apply topical aloe vera cream q6hr (interrupts arachidonic acid cascade)
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***Consider drainage of nonhemorrhagic bullae that interfere with movement
***Consider drainage of nonhemorrhagic bullae that interfere with movement
***Never debride hemorrhagic bullae  
***Never debride hemorrhagic bullae  
**[[Compartment Syndrome]] is a known complication; maintain a high suspicion
*Systemic care
*Systemic care
**Ibuprofen may be helpful in interrupting arachidonic cascade  
**[[Ibuprofen]] may be helpful in interrupting arachidonic cascade  
**Heparin and hyperbaric oxygen of little value
**[[tPA]] or IV Iloprost (not available in US), followed by several days of heparin, reduces digit amputation rate for 3rd and 4th degree frostbite<ref>Bruen KJ et al. Reduction of the incidence of amputation in frostbite injury with thrombolytic therapy. Arch Surg. 2007;142(6):546</ref>
**IV tPA reduces digit amputation rate
**Hyperbaric oxygen therapy is of theoretical benefit but no randomized trials have been performed
*Tetanus
*[[Tetanus]]
**Reported complication of frostbite; provide prophylaxis
**Reported complication of frostbite; provide prophylaxis
*Antibiotics
*Antibiotics
**Controversial
**Controversial
**Penicillin G 500,000 units IV Q6 hours for 48-72 hours
**[[Penicillin G]] 500,000 units IV Q6 hours for 48-72 hours
**Topical bacitracin may be as good or better than IV penicillin
**Topical [[bacitracin]] may be as good or better than IV penicillin
**Silver sulfadiazine cream not consistently beneficial
**Silver [[sulfadiazine]] cream not consistently beneficial
***May interact with aloe vera cream
***May interact with aloe vera cream
*Surgery
*Surgery
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==Disposition==
==Disposition==
*Patients with superficial local frostbite may be discharged home if social circumstances allow
*Patients with superficial local frostbite may be discharged home if social circumstances allow
*Significant injuries will require ICU admission


==Complications==
==Complications==
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==See Also==
==See Also==
*[[Cold injuries]]
*[[Cold injuries]]
==External Links==
*[http://www.emdocs.net/brrr-ed-presentation-evaluation-and-management-of-cold-related-injuries/ emDOCs: Brrr! ED Presentation, Evaluation, and Management of Cold Related Injuries]


==Video==
==Video==

Latest revision as of 13:44, 6 March 2022

Background

Whid chill chart
  • Results from the freezing of tissue
  • It is a disease of morbidity, not mortality
  • Risk correlated with temperature and wind speed
    • Risk is <5% when ambient temperature (includes wind chill) is > –15°C (5°F)
    • Most often occurs at ambient temperature < –20°C (–4°F)
  • Wetness and humidity increase the risk (water has 25x thermal conductivity of air)
  • Can develop within 2-3sec when metal surfaces that are at or below –15°C (5°F) are touched
  • Most commonly affects distal part of extremities, face, nose, and ears
  • High-risk groups: outdoor workers, elderly, homeless, drug or alcohol abusers, psychiatric disease, high-altitude or cold-weather athletes, military personnel
  • "Hunter's response" - prolonged repeated exposure to cold is protective

Pathophysiology

  • Freezing alone is usually not sufficient to cause tissue death
    • Thawing contributes markedly to the degree of injury
    • Endothelial damage, beginning at the point of thaw, is the critical event in frostbite
      • Resulting damage results in swelling, platelet aggregation, vessel thrombosis

Zones of Injury

  1. Zone of Coagulation
    • Most severe and usually most distal
    • Damage is irreversible
  2. Zone of Stasis
    • Middle zone characterized by severe, but possibly reversible, cell damage
    • It is this zone for which treatment may have benefit
  3. Zone of Hyperemia
    • Least severe and usually most proximal
    • Generally recovers without treatment in <10d

Clinical Features

Classification

Visual determination of tissue viability is difficult in first few weeks; classify early injuries as superficial or deep

Degree First (frostnip) Second Third Fourth
Pathophys Partial-skin freezing Full-thickness skin freezing Tissue loss involving entire thickness of skin Extension into subcutaneous tissues, muscle, bone, and tendon; little edema
Symptoms Stinging and burning, followed by throbbing Numbness followed by aching and throbbing Extremity feels like a "block of wood" followed by burning, throbbing, shooting pains Deep, aching joint pain
Course Numbness, erythema, swelling, dysesthesia, desquamation (days later)

Substantial edema over 4-6 hours; skin blisters form within 6-24 hours; Desquamate and form hard black eschars over several days

Hemorrhagic blisters form and are associated with skin necrosis and blue-gray discoloration Skin is mottled with nonblanching cyanosis and formation of deep, dry, black eschar
Pain with rewarming Minimal Mild to moderate Severe None
Prognosis Excellent Good Often poor Extremely poor
Image
PMC2873703 eplasty10e35 fig1.png
PMC3785582 aps-40-510-g001.png
PMC5286755 IJD-62-59-g009.png
PMC4106255 eplasty14ic20 fig1.png

Differential Diagnosis

Cold injuries

Evaluation

Second degree frostbite progression.
  • Usually clinical

Management

  • If hypothermia present, must rewarm to a core temperature of at least 35°C before treating frostbite[1]
  • Remove all wet or constrictive clothing
  • Thawing
    • Do NOT attempt until the risk of refreezing is eliminated
      • Refreezing will cause even more severe damage
    • Rapid rewarming is the core of therapy and should be initiated as soon as possible
      • Extremities
        • Place in water with temperature of 37 to 39°C (98.6 to 102.2°F)
        • Approximately 20-30min, until extremity is pliable and erythematous
        • OR consider 38-40°C in whirlpool bath with antibacterial soap[2]
      • Face
        • Apply moistened compresses soaked in warm water
  • Analgesia
    • Rewarming is very painful
    • Provide parenteral opioids
  • Local wound care
    • Apply topical aloe vera cream q6hr (interrupts arachidonic acid cascade)
    • Affected digits should be separated with cotton and wrapped with sterile, dry gauze
    • Elevate involved extremities
    • Blister removal is controversial
      • Consider drainage of nonhemorrhagic bullae that interfere with movement
      • Never debride hemorrhagic bullae
    • Compartment Syndrome is a known complication; maintain a high suspicion
  • Systemic care
    • Ibuprofen may be helpful in interrupting arachidonic cascade
    • tPA or IV Iloprost (not available in US), followed by several days of heparin, reduces digit amputation rate for 3rd and 4th degree frostbite[3]
    • Hyperbaric oxygen therapy is of theoretical benefit but no randomized trials have been performed
  • Tetanus
    • Reported complication of frostbite; provide prophylaxis
  • Antibiotics
    • Controversial
    • Penicillin G 500,000 units IV Q6 hours for 48-72 hours
    • Topical bacitracin may be as good or better than IV penicillin
    • Silver sulfadiazine cream not consistently beneficial
      • May interact with aloe vera cream
  • Surgery
    • May be required if wet gangrene or infection occurs
    • Usually not performed until full demarcation occurs (3-4wk)

Disposition

  • Patients with superficial local frostbite may be discharged home if social circumstances allow
  • Significant injuries will require ICU admission

Complications

  • Up to 65% of patients with frostbite experience sequelae from their injuries
    • Hypersensitivity to cold, pain, ongoing numbness
    • Arthritis, bone deformities, scars, and skin and nail dystrophia

See Also

External Links

Video

{{#widget:YouTube|id=P3RDlV76d4c}}

References

  1. Handford C, Thomas O, Imray CHE. Frostbite. Emerg Med Clin N Am. 2017;35(2):281–299.
  2. Crawford-Mechem C et al. Frostbite Treatment & Management. Aug 25, 2015. http://emedicine.medscape.com/article/926249-treatment#showall
  3. Bruen KJ et al. Reduction of the incidence of amputation in frostbite injury with thrombolytic therapy. Arch Surg. 2007;142(6):546