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 > | **Risk is <5% when ambient temperature (includes wind chill) is > –15°C (5°F) | ||
**Most often occurs at ambient | **Most often occurs at ambient temperature < –20°C (–4°F) | ||
*Can develop | *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 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; classify early injuries as '''superficial''' or '''deep''' '' | |||
{| {{table}} | |||
| align="center" style="background:#f0f0f0;"|'''Degree''' | |||
| align="center" style="background:#f0f0f0;"|'''First (frostnip)''' | |||
| align="center" style="background:#f0f0f0;"|'''Second''' | |||
| align="center" style="background:#f0f0f0;"|'''Third''' | |||
| align="center" style="background:#f0f0f0;"|'''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'''||[[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]] | |||
|} | |||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
{{Cold injuries DDX}} | {{Cold injuries DDX}} | ||
== | ==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 | ****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 | **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 | ||
** | **[[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> | ||
** | **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
- 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
- Zone of Coagulation
- Most severe and usually most distal
- Damage is irreversible
- Zone of Stasis
- Middle zone characterized by severe, but possibly reversible, cell damage
- 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
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 |
Differential Diagnosis
Cold injuries
- Generalized
- Freezing
- Non-freezing
Evaluation
- 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
- Extremities
- Do NOT attempt until the risk of refreezing is eliminated
- 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
- ↑ Handford C, Thomas O, Imray CHE. Frostbite. Emerg Med Clin N Am. 2017;35(2):281–299.
- ↑ Crawford-Mechem C et al. Frostbite Treatment & Management. Aug 25, 2015. http://emedicine.medscape.com/article/926249-treatment#showall
- ↑ Bruen KJ et al. Reduction of the incidence of amputation in frostbite injury with thrombolytic therapy. Arch Surg. 2007;142(6):546