Handford et al. Extreme Physiology & Medicine 2014, 3:7 http://www.extremephysiolmed.com/content/3/1/7 REVIEW Open Access Frostbite: a practical approach to hospital management Charles Handford1, Pauline Buxton2, Katie Russell3, Caitlin EA Imray4, Scott E McIntosh5, Luanne Freer6,7, Amalia Cochran8 and Christopher HE Imray9,10* Abstract Frostbite presentation to hospital is relatively infrequent, and the optimal management of the more severely injured patient requires a multidisciplinary integration of specialist care. Clinicians with an interest in wilderness medicine/ freezing cold injury have the awareness of specific potential interventions but may lack the skill or experience to implement the knowledge. The on-call specialist clinician (vascular, general surgery, orthopaedic, plastic surgeon or interventional radiologist), who is likely to receive these patients, may have the skill and knowledge to administer potentially limb-saving intervention but may be unaware of the available treatment options for frostbite. Over the last 10 years, frostbite management has improved with clear guidelines and management protocols available for both the medically trained and winter sports enthusiasts. Many specialist surgeons are unaware that patients with severe frostbite injuries presenting within 24 h of the injury may be good candidates for treatment with either TPA or iloprost. In this review, we aim to give a brief overview of field frostbite care and a practical guide to the hospital management of frostbite with a stepwise approach to thrombolysis and prostacyclin administration for clinicians. Keywords: Frostbite, Hypothermia, Rewarming, Thrombolysis, Heparin, TPA, Iloprost Review physiologic response to cold injuries was similar to that of Introduction burn injuries and recognized that warming frozen tissue Frostbite is a freezing, cold thermal injury, which occurs was advantageous for recovery. when tissues are exposed to temperatures below their Today, the presentation of frostbite is increasing freezing point (typically −0.55°C, but can occur as high as within the civilian population, in particular those who 2°C) for a sustained period of time [1]. It is a condition partake in winter sports such as skiing, hiking, mountain that has far-reaching consequences in terms of functional and ice climbing [4]. The outdoors is more accessible, morbidity to a population that are often young, fit and and individuals with limited experience/inadequate prep- healthy prior to the thermal injury. Many frostbite patients aration and protection find themselves at risk of cold in urban areas are homeless and/or suffer from mental thermal injury [5]. Vagrancy, homelessness, industrial in- health issues. Frostbite is well documented in the military jury and malfunctioning or misuse of equipment using and in countries with extreme temperatures for centuries. NO or CO2 have also been described [6,7]. The earliest documented evidence of frostbite may be a Severity of injury depends on factors such as absolute 5,000-year-old pre-Columbian mummy discovered in the temperature, wind chill, duration of exposure, wet/dry Andes [2]. The first report of mass cold injuries was cold, immersion, clothing quality and patient comorbidi- by Baron Larrey, Surgeon-in-Chief to Napoleon's Army ties such as smoking, peripheral vascular disease, neuropa- throughout the invasion of Russia during the winter of thies, Raynaud's disease, mental health issues, substance 1812–1813 [3]. Larrey introduced the concept that the abuse and dementia [1,4,8,9]. Alcohol consumption is po- tentially particularly devastating as it causes heat loss through peripheral vasodilatation and also impairs judge- * Correspondence: [email protected] 9Warwick Medical School, The University of Warwick, Coventry CV4 7AL, UK ment. This may affect the individual's ability to seek ad- 10University Hospital Coventry and Warwickshire NHS Trust, Coventry CV2 equate shelter, compounding the injury. Amputation of 2DX, UK injured parts has been shown to correlate more closely Full list of author information is available at the end of the article ©2014 Handford et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Handford et al. Extreme Physiology & Medicine 2014, 3:7 Page 2 of 10 http://www.extremephysiolmed.com/content/3/1/7 with the duration of cold exposure rather than temperature Remove boots (but consider problems of replacement if [9]. Anatomically, the hands and feet account for 90% of re- swelling occurs), and replace wet gloves and socks with ported injuries [10,11]. Frostbite can also affect the face dry ones. Warm the cold extremity by placing it in a com- (nose, chin, earlobes, cheeks and lips), buttocks/perineum panion's armpit or groin for 10 min and then replace the (from sitting on metal seats) and penis (joggers and Nordic boots/gloves. Rubbing the affected part is not recom- skiers). Patients at the extremes of age (elderly and infants/ mended because of the potential for worsening direct tis- young children) are at greater risk because of immobility sue injury (recommendation grade 1C). and higher surface area-to-mass ratio (children); however, If sensation returns, the patient may mitigate risks (e.g. studies show that frostbite is uncommon in these age add a layer and change to warmer or dryer socks or boots) groups and instead is seen more commonly in adults be- and continue to walk. If there is no return of sensation, tween the ages of 30 and 49 years, most likely due to in- the injured should go to the nearest warm shelter (hut or creased exposure to cold or risk-taking behaviour [10,11]. base camp) and seek medical treatment. If at high altitude Frostbite can result in a wide spectrum of injury, ranging (>4,000 m), supplementary oxygen should be considered from complete resolution without significant sequelae to [11] (recommendation grade 2C). major limb amputation and its functional consequences. Aspirin 75 mg can be given for its rheologic effect. Once in the hospital setting, the best outcomes will be Ibuprofen 12 mg/kg/day divided into two daily doses achieved for the patient when a multidisciplinary approach (maximum of 2,400 mg/day) should be given for its is utilized [11]. In this practical guide, we review key prostaglandin effect (recommendation grade 2C). current frostbite literature, classification strategies and Field rewarming should only be attempted if there is recommendations for management of frostbite in the hos- no further risk of refreezing [14,15]. Tissue that thaws pital setting. then refreezes results in more extensive injury (recom- mendation grade 1B). Literature search The decision to thaw the frostbitten tissue in the field A systematic literature search of the related articles pub- commits to a course of action that may involve pain lished between January 1969 and July 2013 was performed control, maintaining warm water baths at a constant using PubMed (restricted to the English language) with temperature, protecting tissue from further injury dur- keywords ‘frostbite,’ ‘frostbite management’ and ‘freezing ing rewarming and eventual transport. In extreme cir- cold injury’. The search included both human and animal cumstances, it may be better to let a casualty walk on a studies, original research, case series/reports, review arti- frozen limb to safety rather than risk refreezing [16] cles and guidelines. Priority was given to human studies (recommendation grade 1C). and more recent publications since 2005. The studies were identified by title and abstract and screened by the au- Hospital management thors; relevant cross-references were added. Immediate and general care for those admitted with frostbite Recommendation grade On arrival to a hospital setting, it is vitally important to Using the criteria defined by the American College of Chest fully reassess the patient. Underlying unstable comorbid- Physicians (ACCP), each form of intervention was attrib- ities, trauma or hypothermia must be assessed and man- uted a recommendation grade where appropriate. For fur- aged before frostbitten extremities are treated. Moderate ther details on the criteria, please refer to Table 1 [12]. or severe hypothermia should be corrected to bring core temperature above 35°C before initiating frostbite warm- ing [14,17] (recommendation grade 1C). Pre-hospital care and prevention A detailed history should include time the injury oc- Prevention is always preferable, and education of those curred, either early (<24 h) or late (>24 h) as this will dic- working or recreating in cold environments should focus tate some treatment options. History of the conditions on modification of risk factors, selection and use of proper surrounding the injury (i.e. temperature, wind chill, wet/ clothing, optimal nutrition and hydration [4]. Those work- dry exposure, duration and use or not use of thermal pro- ing with equipment that uses coolant such as liquid nitro- tection) can also be helpful. Any pre-hospital treatment genorcarbondioxideshouldalsohaveadequateeducation and time of rewarming, if applicable, should be noted [14]. in safe handling of