Frostbite
Other Names
- Frostbite
- Frostnip
Background
- This page refers to Frostbite, a freezing cold thermal injury that occurs when tissues are exposed to temperatures below their freezing point
- Frostnip is a reversible cold injury that can progress to frostbite
History
- The first physical evidence of frostbite injury is in a 5000-year-old pre-Columbian mummy discovered in the Andes[1]
- Well documented history of afflicting armies including
Epidemiology
- Incidence
- Among mountaineers, one study found a mean incidence of 366 per 1000 population per year[4]
- The incidence for cold injury of 65.6 per 1000 per year in the British Antarctic Survey; 95%of this was for frostbite[5]
- At the Mount Everest Emergency Room, cold exposure accounts for 18.4% of visits, of which 83.7% are attributable to frostbite[6]
Pathophysiology

- General
- Definition: cold thermal injury which occurs when tissues are exposed to temperatures below their freezing point
- Can result in debilitating long-term irreversible morbidity.
- Prevention is the key in preventing morbidity
- 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)
Etiology
- Direct cellular injury and death occurs due to a variety of mechanisms including:[8]
- Ice crystal formation (intracellular and extracellular)
- Cell dehydration and shrinkage
- Electrolyte disturbances
- Denaturation of lipid-protein complexes,
- Thermal shock
- Indirect cellular injury (progressive dermal ischemia)
- Occurs secondary to progressive microvascular insult; more severe than the direct cellular effect
- Following thawing, microvascular thrombosis occurs, resulting in continued cell injury and death
- The following play a role in the progressive ischemia: endothelial damage, intravascular sludging, increased levels of inflammatory mediators and free radicals, reperfusion injury, and thrombosis
Zones
- 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 <10 d
Risk Factors

- Sports
- Mountaineering
- Occupational
- Working with equipment that uses NO2 or CO[10]
- Behavioral/ Socioeconomic[11]
- Alcohol consumption
- Tobacco Use
- Vagrancy
- Unplanned exposure to cold with inadequate protection
- Previous cold injury
- Medical
- Psychiatric illness
- Several medications (eg, b-blockers)
Differential Diagnosis
- General
- Freezing
- Non-Freezing
- Chilblains (Pernio)
- Cold Induced Urticaria
- Trench Foot
- Cold Injury Mimics
- Pressure Necrosis including Acute Compartment Syndrome
- Cellulitis
Clinical Features
- History
- Early recognition is key
- Paresthesias may be the first symptom
- Patients will also report feeling cold, numb and/or clumsy
- Physical Exam
- Appearance is variable and can be misleading
- Color may be yellow-white or mottled blue
- The affected area is insensate and often obviously frozen
- Edema and blistering does not occur until after rewarming
- Special Tests
Evaluation
- Imaging and laboratory evaluation not needed to make diagnosis
- Useful if other pathology is considered
Classification
Visual determination of tissue viability is difficult in first few weeks; classify early injuries as superficial or deep
Management
Prevention
- Equipment
- Appropriate clothing for environment, using a layering system
- Avoid constricting items
- Mittens are preferable to finger gloves and should be attached to the person; spares should be carried
- Appropriate boots for environment/task that fit correctly
- Be careful when removing gloves to perform tasks; never directly touch metal in extreme cold or in moderate cold if wet
- Activity/ Difficulty
- Avoid sweating by reducing exercise intensity if necessary
- Avoid prolonged immobility
- Avoid fatigue
- Weather/ Environment
- Do not climb in adverse weather conditions
- Be aware of the risks associated with increased altitude
- Be aware wind-chill effect
- Planning
- Leaders/commanders must ensure all are fit, trained, and capable of operating in proposed location/climate; this should take into account co morbidities and current medications
- A thorough evacuation and medical plan must be in place before departure; this must include communications
- Other/ Hygiene
- Adequate calorie and fluid intake
- Daily foot care
- Buddy-buddy check system
- Avoid alcohol and smoking
Prehospital
Nonpharmacological
- Return to safety
- Consider turning back, and seek shelter from the elements
- If one party member has a cold injury, others in the party at risk and all should be assessed and removed from the elements
- Removal of clothing and jewelry
- Socks and gloves should be replaced for dry pair
- When removed, swelling may make redonning of boots problematic so only perform in a stable, sheltered location
- Rings or similar items should be removed; subsequent swelling may make this impossible
- Rehydration
- Adequate hydration with oral (ideally warmed) fluids, consider IV if necessary
- Rewarming (prehospital)
- Place affected extremity in another person/s armpit or groin can be attempted for up to 10 minutes
- The person can continue with additional improved protective measures if improved sensation (diagnosis is frostnip)[12]
- If no improvement, the patient should get to the nearest warm shelter, seek medical attention (diagnosis is frostbite)
- Avoid direct content with dry heat, can cause tissue damage via burning or mechanical disruption
- Avoid walking on frostbitten feet if possible. Use splints and pads to minimize movement if walking is required[13]
- Protect individuals from partial rewarming and refreezing during transport
- If transport time <2 hours, “the risks posed by improper rewarming or refreezing outweigh the risks of delaying treatment for deep frostbite.”[14]
- If transport time >2 hours, treatment for hypothermia is prioritized
- Must protect the limb from refreezing
- Prehospital medical facility (base camp medical center)
- Immerse affected body parts in 37 to 39 °C water
- If thermometer is not available, immerse unaffected limb first to ensure water is not too hot
- Once rewarmed, critical not to let the limb refreeze
- Place affected extremity in another person/s armpit or groin can be attempted for up to 10 minutes
- Dressing and blisters
- Allow the limb to air dry following rewarming, do not rub
- Apply allow vera or petroleum jelly to affected area, cover with dressing
- Dressing should not be circumferential or too tight to allow for swelling. Dress between digits if possible.
- Leave blisters intact; they indicate thawing.
- Elevation of limbs can reduce blister size, minimize swelling.
- Antibacterial baths 1-2x daily are recommended, dressings should be applied afterwards
- Portable recompression bag (Gamow bag)
- Hyperbaric pressure bags are widely available, provide simulated reduction at altitude
- May provide two theoretical benefits[15]
- Increased SpO2 (peripheral capillary oxygen saturation)
- Reduction in altitude may minimize cold induced vasoconstriction, combat hypothermia
- Not practical to directly rewarm; may be useful as in field adjunct
- Other
- Avoid tobacco use, smoking
Pharmacological
- Analgesia
- Rewarming is often a painful process
- Enteral and parenteral analgesia should be administered, including opioids
- NSAIDS
- All patients should be started on Ibuprofen for its anti-inflammatory affects in addition to analgesic
- 400 mg two or three times a day is a practical dose
- Oxygen
- Supplemental oxygen in theory increases tissue oxygenation
- Oxygen supplementation at lower altitudes is debated
- Maintain at least 90% saturations
- Tetanus
- Follow standard tetanus guidelines
- Antibiotics
- Controversial; prophylaxis has not been show to reduce amputation[16]
- Administration is based on clinical judgement
- Prehospital thrombolysis
- In hospital tissue plasminogen activator [rTPA]) has resulted in reduced amputation rates
- Effectiveness and use appears to be time dependent, similar to other vascular lesions in which thrombolysis is indicated[17]
- Two case studies describe successful use of thrombolysis at K2 basecamp (need citations)
- Currently there are no clear guidelines to recommend prehospital thrombolysis
- Iloprost
- Has been used in community hospitals in Canada[18]
- Role in prehospital treatment has not been delineated
- Sympathetic blockade/ Regional anesthesia
- A single case report describes prehospital wrist block with good effect[19]
- Can not currently be recommended based on the available evidence.
- Telemedicine
- Facilitates expert opinion in austere locations or with prolonged evacuation times
Hospital
- General Approach
- Follow standard ATLS/ ACLS guidelines as needed based on clinical picture
- Moderate or severe Hypothermia should be addressed first
- This approach may mean initially ignoring a frostbitten limb
- Clinical photography
- Photography should be performed at admission and throughout treatment
- Documents appearance, prevents need for repeated dressing removal
- Imaging
- Multiple imaging modalities can provide important prognostic information
- Technecium99 (99Tc) triple-phase bone scanning accurately predicts amputation risk at 48 hours in 84% of cases[20]
- MRA (magnetic resonance angiography) has been show to estimate level of tissue loss
- Potential advantage over 99Tc scan because it allows direct visualization of occluded vessels, clearer demarcation of ischemia[21]
- Fluoroscopic angioraphy shows vessel patency, should be considered in all patients in which thrombolysis is being considered
- The role of CT angiography is not yet known.
Nonpharmacologic Treatment
- Clothing/ Prevent constriction
- Remove constricting items such as jewelry and rings because swelling will occur with thawing
- Hydration
- Patients are often clinically dehydrated due to cold diuresis, altitude, extreme activity
- Oral vs intravenous fluids should be used based on clinical picture
- Rewarming
- Fully or partially frozen tissue should be rapidly and actively rewarmed
- This should occur in a bath if possible, target temperature 37 to 39 °C
- Povidone iodine or chlorhexidine should be added to prevent infection
- End point of warming is red/purple appearance, tissue becomes pliable
- Often takes 30 minutes, may take longer[22]
- Rewarming may be painful, parenteral analgesia is often required
- Return of sensation is a favorable prognostic sign
- Blister management
- Hemorrhagic blisters indicate injury into the reticular dermis
- Clear blisters suggest a more superficial injury pattern
- The wilderness medical society advises draining clear blisters, leaving hemorrhagic blisters intact[23]
- This process should be performed sterile, may require local anesthetic
- Hypothetically aids in wound care, tissue healing
- Dressings/ Wound care
- Goal: protect and prevent further tissue insult
- Affected limbs should be splinted, elevated, dressed in a loose dressing
- Padding between fingers/ toes is ideal
- Topical aloe vera cream/gel should be applied under the dressing
- Later, protective footwear should be used
- Nutrition
- Recovery requires a high-protein, high-calorie, individually tailored diets[24]
Pharmacologic Treatment

- Analgesia
- Rewarming is painful, pain should be addressed
- NSAIDS
- All patients should be started on Ibuprofen for its anti-inflammatory affects in addition to analgesic
- 400 mg two or three times a day is a practical dose
- This can be increased up to 2400 mg/day
- Aspirin should be avoided due to theoretical blockade of some prostaglandins which promote wound healing
- Antibiotics
- Should be given if suspected or proven infection
- Prophylaxis is controversial; no evidence based guidelines or society recommendations are available
- Consider in high risk patients such as malnutrition, immunosuppression, large total surface area of frostbite, etc
- Tetanus toxoid
- Standard tetanus booster can be administered
- Thrombolytic therapy
- Goal: reverse microvascular thrombosis, restore blood flow
- Medications: TPA most commonly used
- Delivery: targeted endovascular therapy is optimal
- Literature
- Twomey et al: in cases with no freese-thaw cycles, exposure < 24 hours or warm ischemia time of more than 6 hours, TPA resulsted in reduction in expected amputations[25]
- Bruen et al: TPA within 24 hours reduced amputation rate from 41% to 10%[26]
- Gonzaga et al: following thrombolysis, amputation rate was 31.4% for 472 at risk digits[27]
- Cauchy et al: TPA reduced amputation rates (3.1%) compared to buflomedil (39.6%), but was inferior to iloprost (0%)[28]
- Decision to administer
- Injury must be severe with potential tissue loss, ocurred within the last 24 hours without freeze-thaw cycles
- There must be no contraindications (i.e. recent trauma or surgery, bleeding diathesis, neurological impairment, etc)
- Access to a critical care unit
- Intra-arterial administeration is preferred
- Co-administeration of papaverine may be needed to reduce vasospasm
- Heparin should be used as an adjunctive treatment to minimize new clot formation
- Iloprost
- Prostacyclin analogue with vasodilatory properties, reduces capillary permability, supresses platelet aggregation, promotes fibrinolysis[29]
- Note that it is not available in the US
- Research
- Cauch et al: reduced amputation among 407 patients that were at risk[30]
- Case reports have also suggested benefit
- Administered as an IV infusion
- Advantages over TPA
- Does not require radiological intervention, can be administered on a monitored ward, used more than 24 hours after injury, not contraindicated after trauma
Surgical Treatment Options
- Fasciotomy
- Acute Compartment Syndrome can develop with rewarming and the subsequent edema
- Important to monitor for signs and symptoms
- Note that this can be challenging in the context of frosbite
- Amputation
- Ideally, surgical amputation should be avoided until autoamputation/demarcation awaited.
- Indications for early amputation include
- Wet gangrene
- Liquefaction
- Overwhelming infection
- Spreading sepsis
- Imaging can help determine when this is necessary
- Tissue care
- Goal is to maintain and restore good quality tissue after healing
- Attention should be paid to loadbearing and functionally significant areas
- There are no evidence based guidelines for management
- Secondary intention is likely the best course of action
- Topical negative pressure facilitates wound healing[31]
- Surgical flap is an alternative to secondary intention
- Especially in areas significant areas (hands, feet, poor vascular bed)
Potential Adjunctive Therapies
- Hyperbaric oxygen therapy
- Sympathectomy
- Sympathectomy blocks the nerve, resulting in reflex vasodilation and increased blood flow[34]
- This can be surgical or chemical
- It is not currently recommended in acute frostbite management due to mixed results
- However, in chronic complications including vasopspasm, hyperhidrosis, it may have benefit
- Topical agents
- Aloe vera is accepted as the best practices baesd on the available evidence
- Further investigation into the following should be considered
- Poly-l-arginine contained in lotion
- Ganoderma triterpenids
- Nanogel delivery method
Rehab and Return to Play
Rehabilitation
- Variable, depends on affected area(s)
- Goal: return the individual to the optimal function and independence.
- Patients will require a multidisciplinary team:
- Physicians
- Occupational therapists
- Specialist nurses
- Physiotherapist
- Prosthetist/ orthotist (if needed)
- Mental health (if needed)
Return to Play/ Work
- Can take several weeks or months depending on the severity of the injury
- A player should not return to play the same day after thawing
Complications and Prognosis
Prognosis
- Generally drive by severity
- Frostnip: excellent
- Frostbite grade 2: good
- Frostbite grade 3: poor
- Frostbite grade 4: extremally poor
Complications
- Functional Loss
- Cold sensitivity
- Taylor et al in patients with significant frostbite injury[34]
- 53% showed subsequent cold hypersensitivity
- 40% numbness of the digits
- 33% had reduced sensitivity to touch
- Taylor et al in patients with significant frostbite injury[34]
- Chronic pain
- Common and troublesome for physicians
- Early involvement with pain management specialist is recommended
- Potential medications include Amitriptyline, Gabapentinoids
- Early introduction of neuropathic analgesics may reduce the risk of developing chronic pain[35][36]
- Chronic ulceration
- Increased risk of chronic ulceration in patients with
- Areas of poor tissue quality
- Altered biomechanics and pressure areas
- Increased risk of chronic ulceration in patients with
- Must be monitored for malignant transformation[37]
- Arthritis
- Arthritis following frostbite is well reported[38]
- Can also see
- Localized osteoporosis
- Subchondral bone loss
- Epiphyseal injuries in the skeletally immature
See Also
References
- ↑ Post PW, Donner DD. Frostbite in a pre-Columbian mummy. Am J Phys Anthropol 1972;37(2):187–91.
- ↑ Golden FS, Francis TJ, Gallimore D, et al. Lessons from history: morbidity of cold injury in the Royal Marines during the Falklands Conflict of 1982. Extrem Physiol Med 2013;2(1):23.
- ↑ Larrey DJ, Hall RW. Memoirs of military surgery. 1st American from the 2d Paris ed, vol. 6. Baltimore (MD): Joseph Cushing; 1814.
- ↑ Harirchi I, Arvin A, Vash JH, et al. Frostbite: incidence and predisposing factors in mountaineers. Br J Sports Med 2005;39(12):898–901 [discussion: 901].
- ↑ Cattermole TJ. The epidemiology of cold injury in Antarctica. Aviat Space Environ Med 1999;70(2):135–40.
- ↑ Nemethy M, Pressman AB, Freer L, et al. Mt Everest Base Camp Medical Clinic “Everest ER”: epidemiology of medical events during the first 10 years of operation. Wilderness Environ Med 2015;26(1):4–10.
- ↑ Handford, Charles, Owen Thomas, and Christopher HE Imray. "Frostbite." Emergency Medicine Clinics 35.2 (2017): 281-299.
- ↑ Auerbach PS. Wilderness medicine. 6th edition. Philadelphia: Elsevier/Mosby; 2012.
- ↑ Image courtesy of weather.gov, "Wind Chill Chart"
- ↑ Sever C, Kulahci Y, Acar A, et al. Unusual hand frostbite caused by refrigerant liquids and gases. Ulus Travma Acil Cerrahi Derg 2010;16(5):433–8.
- ↑ Makinen TM, Jokelainen J, Nayha S, et al. Occurrence of frostbite in the general population–work-related and individual factors. Scand J Work Environ Health 2009;35(5):384–93.
- ↑ Syme D, Commission IM. Position paper: on-site treatment of frostbite for mountaineers. High Alt Med Biol 2002;3(3):297–8.
- ↑ McIntosh SE, Hamonko M, Freer L, et al. Wilderness Medical Society practice guidelines for the prevention and treatment of frostbite. Wilderness Environ Med 2011;22(2):156–66.
- ↑ Zafren K, Giesbrecht G. State of Alaska: cold injuries guidelines. Juneau (Alaska): Department of Health and Social Services, Division of Public Health; 2014.
- ↑ Cauchy E, Leal S, Magnan MA, et al. Portable hyperbaric chamber and management of hypothermia and frostbite: an evident utilization. High Alt Med Biol 2014; 15(1):95–6.
- ↑ Malhotra MS, Mathew L. Effect of rewarming at various water bath temperatures in experimental frostbite. Aviat Space Environ Med 1978;49(7):874–6.
- ↑ 17.0 17.1 Handford C, Buxton P, Russell K, et al. Frostbite: a practical approach to hospital management. Extrem Physiol Med 2014;3:7.
- ↑ Poole A, Gauthier J. Treatment of severe frostbite with iloprost in northern Canada. CMAJ 2016;188(17–18):1255–8.
- ↑ Pasquier M, Ruffinen GZ, Brugger H, et al. Pre-hospital wrist block for digital frostbite injuries. High Alt Med Biol 2012;13(1):65–6.
- ↑ Cauchy E, Marsigny B, Allamel G, et al. The value of technetium 99 scintigraphy in the prognosis of amputation in severe frostbite injuries of the extremities: a retrospective study of 92 severe frostbite injuries. J Hand Surg Am 2000;25(5): 969–78
- ↑ Raman SR, Jamil Z, Cosgrove J. Magnetic resonance angiography unmasks frostbite injury. Emerg Med J 2011;28(5):450.
- ↑ McCauley RL, Hing DN, Robson MC, et al. Frostbite injuries: a rational approach based on the pathophysiology. J Trauma 1983;23(2):143–7.
- ↑ McIntosh SE, Opacic M, Freer L, et al. Wilderness Medical Society practice guidelines for the prevention and treatment of frostbite: 2014 update. Wilderness Environ Med 2014;25(4 Suppl):S43–54.
- ↑ Kiss TL. Critical care for frostbite. Crit Care Nurs Clin North Am 2012;24(4): 581–91.
- ↑ 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(6):1350–4
- ↑ 17. Bruen KJ, Ballard JR, Morris SE, et al. Reduction of the incidence of amputation in frostbite injury with thrombolytic therapy. Arch Surg 2007;142(6):546–51.
- ↑ Gonzaga T, Jenabzadeh K, Anderson CP, et al. Use of intraarterial thrombolytic therapy for acute treatment of frostbite in 62 patients with review of thrombolytic therapy in frostbite. J Burn Care Res 2015;37(4):e323–34.
- ↑ Cauchy E, Cheguillaume B, Chetaille E. A controlled trial of a prostacyclin and rt- PA in the treatment of severe frostbite. N Engl J Med 2011;364(2):189–90.
- ↑ Auerbach PS. Wilderness medicine. 6th edition. Philadelphia: Elsevier/Mosby; 2012.
- ↑ Cauchy E, Cheguillaume B, Chetaille E. A controlled trial of a prostacyclin and rt-PA in the treatment of severe frostbite. N Engl J Med 2011;364(2):189–90.
- ↑ Orgill DP, Bayer LR. Negative pressure wound therapy: past, present and future.Int Wound J 2013;10(Suppl 1):15–9.
- ↑ Kemper TC, de Jong VM, Anema HA, et al. Frostbite of both first digits of the foot treated with delayed hyperbaric oxygen: a case report and review of literature. Undersea Hyperb Med 2014;41(1):65–70.
- ↑ Dwivedi DA, Alasinga S, Singhal S, et al. Successful treatment of frostbite with hyperbaric oxygen treatment. Indian J Occup Environ Med 2015;19(2):121–2.
- ↑ 34.0 34.1 Taylor MS. Lumbar epidural sympathectomy for frostbite injuries of the feet. Mil Med 1999;164(8):566–7.
- ↑ Aldington DJ, McQuay HJ, Moore RA. End-to-end military pain management. Philos Trans R Soc Lond B Biol Sci 2011;366(1562):268–75.
- ↑ McGreevy K, Bottros MM, Raja SN. Preventing chronic pain following acute pain: risk factors, preventive strategies, and their efficacy. Eur J Pain Suppl 2011;5(2):365–72.
- ↑ Rossis CG, Yiacoumettis AM, Elemenoglou J. Squamous cell carcinoma of the heel developing at site of previous frostbite. J R Soc Med 1982;75(9):715–8.
- ↑ Kahn JE, Lidove O, Laredo JD, et al. Frostbite arthritis. Ann Rheum Dis 2005; 64(6):966–7
Created by:
John Kiel on 30 June 2019 22:54:19
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