Guideline sources The following summarized guidelines for the evaluation and management of frostbite are prepared by our editorial team based on guidelines from the Wilderness Medical Society (WMS 2019; 2012) and the American College of Chest Physicians (ACCP 2014). 1 2 3 Guidelines 1. Diagnostic investigations Diagnostic imaging: As per WMS 2019 guidelines: Obtain noninvasive imaging with technetium pyrophosphate or MRA, if available, at an early stage in patients with delayed presentation of frostbite (4-24 hours from the time of the frostbite thawing) to assess tissue viability and guide timing and extent of amputation. B Consider obtaining angiography, technetium-99 bone scan and/or MRI, in conjunction with clinical findings, to assist in determining surgical margins. B As per ACCP 2014 guidelines: https://web.pathway.md/diseases/recMAJ6C5n4kFGgpd 1/8 6/29/23, 4:07 AM Frostbite Pathway Obtain angiography and/or technecium-99 triple-phase bone scan in patients with deep injuries to assist in directing therapy and for prognostic purposes. B Obtain repeated angiography every 12-24 hours to evaluate the response to therapy. B 2. Respiratory support Suplemental oxygen: Do not administer routine supplemental oxygen in non-hypoxic patients. D Consider administering supplemental oxygen in the field delivered by face mask or nasal cannula in patients with hypoxia (oxygen saturation < 88%) or at high altitude (> 4,000 m). C Hyperbaric oxygen therapy: As per WMS 2019 guidelines, insufficient evidence to recommend hyperbaric oxygen therapy for the treatment of patients with frostbite. I As per ACCP 2014 guidelines, insufficient evidence to recommend the routine use of hyperbaric oxygen therapy for the treatment of patients with frostbite. I 3. Medical management Setting of care: As per WMS 2019 guidelines, decide on hospital admission and discharge on an individual basis, including factors such as severity of the injury, coexisting injuries, comorbidities, and need for hospital-based interventions (tPA, vasodilators, surgery) or supportive therapy, as well as ease of access to appropriate community medical and nursing support. B Show 3 more As per ACCP 2014 guidelines, obtain full reassessment of patients on arrival to a hospital setting. Assess and manage underlying unstable comorbidities, trauma or hypothermia before initiating treatment for frostbitten extremities. B Hydration: As per WMS 2019 guidelines, administer fluids both in hospital and field clinic to prevent clinical dehydration. B Show 4 more As per ACCP 2014 guidelines: Administer oral or IV rehydration depending on the severity and ability of the patient to tolerate oral fluids. B Administer warmed IV fluids in patients with hypothermia, as dehydration may be compounded by cold diuresis due to suppression of ADH. B Analgesics: As per WMS 2019 guidelines, administer ibuprofen in the field at a dose of 12 mg/kg/day divided BID to a maximum of 2,400 mg/day divided QID. B Show 2 more https://web.pathway.md/diseases/recMAJ6C5n4kFGgpd 2/8 6/29/23, 4:07 AM Frostbite Pathway As per ACCP 2014 guidelines, consider administering aspirin 75 mg for its rheologic effect. C Show 3 more Thrombolytic therapy: As per WMS 2019 guidelines, obtain a risk(cid:0)/benefit analysis when considering thrombolytic therapy. Consider administering thrombolytic therapy only in patients with deep injuries with potential for significant morbidity (such as extending into the proximal interphalangeal joints of digits). Show 4 more As per ACCP 2014 guidelines: Recognize that recombinant tPA is contraindicated in trauma and its efficacy is reduced if used beyond 24 hours. B Discontinue recombinant tPA when perfusion is restored to distal vessels or at 48 hours if no improvement is observed. B Heparin: Insufficient evidence to support the use of LMWH or UFH for initial management of patients with frostbite in the field or hospital/field clinic. I Consider administering heparin 500 units/hours as adjunctive therapy in tPA protocols. B Low molecular weight dextran: consider administering warmed IV low molecular weight dextran both in the field and hospital/field clinic to decrease blood viscosity by preventing RBC aggregation and formation of microthrombi. C Show 2 more Vasodilators: As per WMS 2019 guidelines, consider administering IV iloprost as first-line therapy in patients with grade 3-4 frostbite within < 72 hours after injury, if tPA is contraindicated, and in austere environments where tPA infusion is considered risky or evacuation to a treatment facility will be delayed. B Show 3 more As per ACCP 2014 guidelines, consider administering iloprost if there is a history of trauma or if the exposure occurred over 24 hours ago. B Antibiotics: As per WMS 2019 guidelines, administer systemic antibiotics, either oral or parenteral, in the hospital/field clinic in patients with significant trauma, other potential infectious sources, or signs and symptoms of cellulitis or sepsis. B As per ACCP 2014 guidelines: Consider administering prophylactic antibiotics in patients with severe injuries (grades 3-4), particularly if associated with significant edema or malnutrition (homeless, chronic alcohol abuse or return from extreme altitude). B Administer systemic antibiotics in patients with proven infection, trauma and cellulitis. B Management of hypothermia: As per WMS 2019 guidelines, treat moderate and severe hypothermia before initiating treatment for frostbite injury, both in the field and hospital/field clinic. Consider treating mild https://web.pathway.md/diseases/recMAJ6C5n4kFGgpd 3/8 6/29/23, 4:07 AM Frostbite Pathway hypothermia concurrently with the frostbite injury, both in the field and hospital/field clinic. B As per ACCP 2014 guidelines, treat moderate or severe hypothermia to > 35 C before initiating frostbite warming. B Management of corneal frostbite: offer artificial tears, topical antibiotics, topical NSAIDs, and cycloplegics in patients with corneal frostbite. B 4. Nonpharmacologic interventions Protection: As per WMS 2019 guidelines, protect the frozen tissue from further damage if a body part is frozen in the field. Remove jewelry or other constrictive extraneous material from the body part. Do not rub or apply ice or snow to the affected area. Show 7 more As per ACCP 2014 guidelines, move patients with frostbite out of the wind, provide shelter and give warm fluids. B Show 4 more Passive thawing: As per WMS 2019 guidelines, allow frozen tissue to thaw if environmental and situational conditions allow for spontaneous or slow thawing. B Show 4 more As per ACCP 2014 guidelines, recognize that the decision to thaw the frostbitten tissue in the field commits to a course of action, including pain control, maintaining warm water baths at a constant temperature, protecting tissue from further injury during rewarming and eventual transport. Consider letting patients to walk on a frozen limb to safety rather than risk refreezing in extreme circumstances. B Active rewarming: As per WMS 2019 guidelines, initiate field rewarming as follows only if the frozen part can be kept thawed and warm until the patient arrives at definitive care: perform field rewarming by warm water bath immersion if the proper resources are available and definitive care is > 2 hours distant; avoid using other heat sources (such as fire, space heater, oven, heated rocks) because of the risk of thermal burn injury heat the water to 37-39 C (98.6-102.2 F), using a thermometer to maintain this range; determine a safe water temperature by placing a caregiver's uninjured hand in the water for at least 30 seconds to confirm that the water temperature is tolerable and will not cause burn injury, if a thermometer is not available consider circulating water around the frozen tissue to help maintain correct temperature warm the water continuously and carefully to the target temperature, as the water may cool quickly after the rewarming process is started avoid pressing skin press against the bottom or sides of the pot if the frozen part is being rewarmed in a pot complete rewarming when the involved part takes on a red or purple appearance and becomes soft and pliable to the touch, a process usually accomplished in approximately 30 minutes, but varying depending on the extent and depth of injury https://web.pathway.md/diseases/recMAJ6C5n4kFGgpd 4/8 6/29/23, 4:07 AM Frostbite Pathway allow the affected tissues to air dry or gently dry with a blotting technique (not rubbing) to minimize further damage. B Show 4 more As per ACCP 2014 guidelines, initiate field rewarming only if there is no further risk of refreezing. Recognize that tissue that thaws then refreezes results in more extensive injury. B Show 3 more Aloe vera: As per WMS 2019 guidelines: Consider applying topical aloe vera to thawed tissue in the field before application of dressings. C Apply topical aloe vera cream or gel to the thawed tissue in the hospital/field clinic before applying dressings. Reapply topical aloe vera cream or gel at each dressing change, or every 6 hours. B As per ACCP 2014 guidelines, apply topical aloe vera cream or gel (a potent antiprostaglandin agent) to thawed tissue before applying dressings. B Hydrotherapy: insufficient evidence to recommend specific temperature, timing, or duration of hydrotherapy for the treatment of patients with forstbite after thawing. I 5. Surgical interventions Dressing: As per WMS 2019 guidelines, insufficient evidence to support applying a dressing to a frostbitten part intended to remain frozen until rewarming can safely be achieved. I Show 2 more As per ACCP 2014 guidelines: Obtain detailed assessment of severe injuries. Consider appraising and debriding blisters under general anesthesia. B Splint, elevate and wrap the affected part in a loose, protective dressing with padding between affected digits. B Debridement: As per WMS 2019 guidelines: Do not perform routine debridement of blisters in the field. Perform aspiration of blisters and apply dry gauze dressing in the field to minimize infection risk if a clear, fluid-filled blister is tense and at high risk for rupture during evacuation. Do not aspirate or debride hemorrhagic bullae in the field. D Consider debriding or aspirating clear, cloudy, or tense blisters in the hospital/field clinic at the discretion of the treating provider, with consideration of patient circumstances. C As per ACCP 2014 guidelines, do not perform debridement in patients with deep injuries until imaging is performed. D Fasciotomy: https://web.pathway.md/diseases/recMAJ6C5n4kFGgpd 5/8 6/29/23, 4:07 AM Frostbite Pathway As per WMS 2019 guidelines, perform prompt surgical decompression for limb salvage in patients elevated compartment pressures. B As per ACCP 2014 guidelines, perform post-thaw fasciotomy if reperfusion is compromised by compartment syndrome. B Sympathectomy: As per WMS 2019 guidelines, insufficient evidence to recommend surgical sympathectomy for the treatment of patients with frostbite. I As per ACCP 2014 guidelines, consider performing sympathectomy with a great caution for the management of long-term sequelae of frostbite, such as pain (often due to vasospasm), paresthesias and hyperhidrosis, recognizing that it is irreversible and the availability of alternative IV vasodilators. Amputation: As per WMS 2019 guidelines: Perform expeditious amputation if the patient develops signs and symptoms of sepsis attributed to infected frostbitten tissue. Delay amputation if otherwise until definitive demarcation occurs, a process that may take weeks to months. B Assess the need for and the timing of any amputations by a surgeon with experience evaluating and treating frostbite. Consider obtaining a telemedicine or electronic consultation with a surgical frostbite expert to guide local surgeons with amputation when no local expert is available. B As per ACCP 2014 guidelines, avoid performing immediate amputation unless there is wet gangrene, liquefaction, overwhelming infection or spreading sepsis, recognizing that premature amputation increases morbidity and is likely to lead to poor subsequent function. D 6. Preventative measures Protection from cold: Advise the following measures to minimize the exposure of tissue to cold to prevent frostbite: avoiding environmental conditions predisposing to frostbite, specifically < -15 C or 5 F, even with low wind speeds protecting skin from moisture, wind, and cold avoiding perspiration or wet extremities increasing insulation and skin protection (such as adding clothing layers, changing from gloves to mitts) ensuring beneficial behavioral responses to changing environmental conditions (such as not being under the influence of illicit drugs, alcohol, or extreme hypoxemia) using chemical hand and foot warmers and electric foot warmers to maintain peripheral warmth (warmers should be close to body temperature before being activated and must not be placed directly against skin or constrict flow if used within a boot) regularly checking oneself and the group for extremity numbness or pain and warming the digits and/or extremities as soon as possible if there is concern that frostbite may be developing https://web.pathway.md/diseases/recMAJ6C5n4kFGgpd 6/8 6/29/23, 4:07 AM Frostbite Pathway recognizing frostnip or superficial frostbite before it becomes more serious minimizing duration of cold exposure. B Show 2 more Maintaining peripheral perfusion: Advise the following preventative measures to ensure local tissue perfusion: maintaining adequate core temperature and body hydration minimizing the effects of known diseases and medications, and substances (including awareness and symptoms of alcohol and drug use) that might decrease perfusion covering all skin and the scalp to insulate from the cold minimizing blood flow restriction, such as occurs with constrictive clothing, footwear, or immobility ensuring adequate nutrition using supplemental oxygen in severely hypoxic conditions (such as > 7,500 m). B Advise exercising to increase the core and peripheral temperatures to prevent frostbite. B Tetanus prophylaxis: As per WMS 2019 guidelines, administer tetanus prophylaxis according to standard guidelines. B As per ACCP 2014 guidelines, follow standard guidelines to determine the need for the tetanus toxoid administration, as frostbite injuries are not inherently tetanus-prone wounds. B 7. Follow-up and surveillance Recovery: Offer appropriate footwear and orthotics to provide optimal function in patients with insensate affected limb. B Offer early multidisciplinary rehabilitation produces for better long-term functional results. B Clinical findings Symptoms Past medical history Clumsiness AUD Edema Integument exam Numbness Pain Bruises Paresthesia Cyanosis Digital necrosis Social history Gangrene Illicit drug use Pallor Skin blisters Skin erythema https://web.pathway.md/diseases/recMAJ6C5n4kFGgpd 7/8 6/29/23, 4:07 AM Frostbite Pathway References 1. Scott E McIntosh, Luanne Freer, Colin K Grissom et al. Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Frostbite: 2019 Update. Wilderness Environ Med. 2019 Dec;30 4S S19 S32. Open 2. Charles Handford, Pauline Buxton, Katie Russell et al. Frostbite: a practical approach to hospital management. Extrem Physiol Med. 2014; 3 7. Open 3. Brandy Drake, Ryan Paterson, Geoffrey Tabin et al. Wilderness Medical Society practice guidelines for treatment of eye injuries and illnesses in the wilderness. Wilderness Environ Med. 2012 Dec;23 4 325 36. Open 4. Scott E McIntosh, Matthew Hamonko, Luanne Freer et al. Wilderness Medical Society practice guidelines for the prevention and treatment of frostbite. Wilderness Environ Med. 2011 Jun;22 2 156 66. Open https://web.pathway.md/diseases/recMAJ6C5n4kFGgpd 8/8