Climate, diseases and medicine: the welfare of soldiers during the East Asian War of 1592-1598

This article examines the care provided for the welfare of soldiers by the three combatant countries - China, Korea and Japan - during the East Asian War of 1592-8. Also known as the Imjin War, this large-scale military conflict can also be understood as an encounter between different state cultures and strategies of military medicine. This study focuses on cold-induced injuries, epidemic outbreaks and external wounds suffered during the war. I illuminate provision of prophylactic measures against cold by the Ming state, as well as attempts by the Sino-Chosŏn medical alliance to manage epidemics and treat wounded soldiers. I contrast these measures with the lack of similar centralised support for the Japanese forces, and examine the effect these differences had upon on military outcomes during the war. The difference in the amount of time, efforts and resources that the three combatant states devoted to sick and injured soldiers has implications not only for our understanding of the war but also for illuminating the early modern history of military medicine in East Asia. By exploring East Asian military medicine during and after the Imjin War, this article responds to recent calls for more detailed examination of histories of military medicine in premodern periods and non-European regions.

Update on Cold-Induced Injuries

Cold-induced injuries are a major challenge for burn surgeons, leading to significant sequelae for the patients including amputations, long-term disability, and death. Rapid assessment and diagnosis are essential for optimal outcomes. Various therapies have emerged to improve outcomes. Topical, oral, and intravenous agents have shown to minimize the impact of cold-induced injuries. Thrombolytics have shown the greatest promise in improving tissue perfusion outcomes in cold-induced injuries. This article provides an update on the evidence-based assessment and management of cold-induced injuries, as well as reviews outcomes and future directions of this challenging pathology.

A 15-year review of characteristics and outcomes of patients leaving against medical advice

PURPOSE

Discharging against medical advice can have significant, detrimental effects on burn patient outcomes as well as higher hospital readmission rates and healthcare expenditures. The goal of this study is to identify characteristics of patients who left against medical advice and suggest solutions to mitigate these factors. Data were collected at our American Burn Association verified Burn Unit over a 15-year period.

RESULTS

Between 2007 and 2022, 37 patients were identified as having left against medical advice from the burn unit. The average patient age was 37 years old with 64.9% being male, and 70.2% were identified as having a substance abuse history. The majority (51.4%) had Medicaid or State health insurance, 29.7% had no insurance, and 18.9% had private insurance. The mechanism of injury was most commonly frostbite (43.2%). The majority sustained < 1% total body surface area injuries. Most (83.7%) had social work and/or case management involved during their admission, and all (100%) had their involvement if the length of admission was greater than one day. Over half (59.5%) returned to the ED within 2 weeks with complications.

CONCLUSIONS

This study found that patients discharging against medical advice from the burn unit suffered from smaller injuries, often due to cold related injuries. These patients had comorbid substance abuse or psychiatric histories, and the majority had Medicaid or state health insurance. Recruiting interdisciplinary care members, including social work, psychiatry, and addiction medicine, early may help these patients by encouraging completion of their hospital care and setting up crucial follow-up care.

Surgery under siege: A case study of leg amputation in 18th century Louisbourg, Nova Scotia, Canada

OBJECTIVE

Paleopathological analysis of a below-knee amputation was conducted to explore the sociocultural reasons why the amputation took place.

MATERIALS

Older adolescent male (18-21 years) from the New Englander mass burial at the 18th century Fortress of Louisbourg.

METHODS

Macroscopic assessment and archival data.

RESULTS

A surgical amputation of the right tibia and fibula, distal to the knee was identified. The cross-sectional diaphysis of the leg has kerf marks and a splinter (breakaway point) at the posterior-lateral border of the tibia suggesting the leg gave way from its own weight or was manually removed once most of the sawing was complete.

CONCLUSIONS

Archival records suggest frostbite from prolonged exposure to freezing temperatures and trauma from unsafe working conditions at the Fortress were the main causes that led to amputation.

SIGNIFICANCE

This case study highlights the importance of contextualizing cases of amputation to understand factors leading to the amputation procedure and techniques used in the past, and the social and living conditions of the individual.

LIMITATIONS

Observations were restricted to skeletal material as soft tissue decomposed and there was no material evidence suggestive of amputation associated with this individual in their grave.

SUGGESTIONS FOR FUTURE RESEARCH

Full trauma assessment of the Fortress of Louisbourg skeletal collection to provide additional insight into injury sustained at Louisbourg and 18th century surgical practices.

Prolonged critical avalanche burial for nearly 23 h with severe hypothermia and severe frostbite with good recovery: a case report

BACKGROUND

Accidental hypothermia with severe frostbite is a rare combination of injuries with a high risk for long-term sequelae. There are widely accepted recommendations for the management of avalanche victims and for frostbite treatment, but no recommendation exists for the treatment of frostbite in severe hypothermic patients, specifically for the management of hypothermic avalanche victims presenting with frostbite.

CASE PRESENTATION

We present a case of a previously healthy, 53-year-old male skier who was critically buried by an avalanche at 2300 m of altitude at an ambient temperature of - 8 °C for nearly 23 h. The victim was found with the right hand out of the snow and an air connection to outside. He was somnolent with Glasgow Coma Scale 11 (Eye 4, Verbal 2, Motor 5) and spontaneously breathing, in a severely hypothermic state with an initial core temperature of 23.1 °C and signs of cold injuries in all four extremities. After rescue and active external forced air rewarming in the intensive care unit, the clinical signs of first-degree frostbite on both feet and the left hand vanished, while third- to fourth-degree frostbite injuries became apparent on all fingers of the right hand. After reaching a core body temperature of approximately 36 °C, aggressive frostbite treatment was started with peripheral arterial catheter-directed thrombolysis with alteplase, intravenous iloprost, ibuprofen, dexamethasone and regional sympathicolysis with a right-sided continuous axillary block. After ten months, the patient had no tissue loss but needed neuropathic pain treatment with pregabalin.

CONCLUSION

The combination of severe accidental hypothermia and severe frostbite is rare and challenging, as drug metabolism is unpredictable in a hypothermic patient and no recommendations for combined treatment exist. There is general agreement to give hypothermia treatment the priority and to begin frostbite treatment as early as possible after full rewarming of the patient. More evidence is needed to identify the optimal dosage and time point to initiate treatment of frostbite in severely hypothermic patients. This should be taken into consideration by future treatment recommendations.

Dermorphin [D-Arg2, Lys4] (1-4) Amide Alleviates Frostbite-Induced Pain by Regulating TRP Channel-Mediated Microglial Activation and Neuroinflammation

Cold injury or frostbite is a common medical condition that causes serious clinical complications including sensory abnormalities and chronic pain ultimately affecting overall well-being. Opioids are the first-choice drug for the treatment of frostbite-induced chronic pain; however, their notable side effects, including sedation, motor incoordination, respiratory depression, and drug addiction, present substantial obstacle to their clinical utility. To address this challenge, we have exploited peripheral mu-opioid receptors as potential target for the treatment of frostbite-induced chronic pain. In this study, we investigated the effect of dermorphin [D-Arg2, Lys4] (1-4) amide (DALDA), a peripheral mu-opioid receptor agonist, on frostbite injury and hypersensitivity induced by deep freeze magnet exposure in rats. Animals with frostbite injury displayed significant hypersensitivity to mechanical, thermal, and cold stimuli which was significant ameliorated on treatment with different doses of DALDA (1, 3, and 10 mg/kg) and ibuprofen (100 mg/kg). Further, molecular biology investigations unveiled heightened oxido-nitrosative stress, coupled with a notable upregulation in the expression of TRP channels (TRPA1, TRPV1, and TRPM8), glial cell activation, and neuroinflammation (TNF-α, IL-1β) in the sciatic nerve, dorsal root ganglion (DRG), and spinal cord of frostbite-injured rats. Treatment with DALDA leads to substantial reduction in TRP channels, microglial activation, and suppression of the inflammatory cascade in the ipsilateral L4-L5 DRG and spinal cord of rats. Overall, findings from the present study suggest that activation of peripheral mu-opioid receptors mitigates chronic pain in rats by modulating the expression of TRP channels and suppressing glial cell activation and neuroinflammation.

Acupuncture and herbal medicine in preventing amputation and promoting tissue regeneration in severe frostbite: A case series

BACKGROUND

Frostbite is a medically significant form of tissue injury that can lead to the potential need for amputation or necessitate tissue regeneration. It occurs most frequently at cryogenic temperatures in extreme altitude climbing, winter sports, and military activities. While acupuncture and herbal medicine have been reported to possess tissue regeneration effectiveness, there is currently no clinical evidence supporting their use in treating grade 3 frostbite cases at risk of amputation.

CASE PRESENTATION

Three patients were diagnosed with grade 3 frostbite based on the extent and severity of tissue damage after alpine climbing in the Himalayas. After an urgent treatment, partial body amputation was advised. In order to seek any complementary treatment options and avoid amputation, they were referred to a frostbite expert in traditional Korean medicine. They received a comprehensive treatment consisting of acupuncture, bloodletting, direct moxibustion, and herbal medicine. All the patients showed notable healing of the damaged tissue, which prevented the need for amputation. No adverse effects or other sequelae were observed.

CONCLUSION

This case series suggests that complementary medicine, primarily acupuncture and herbal medicine, could be effective for severe frostbite. Further studies with larger sample sizes and control groups are needed to determine the efficacy and safety of this treatment modality for frostbite management.

Frostbite treatment: a systematic review with meta-analyses

INTRODUCTION

Our objective was to perform a systematic review of the outcomes of various frostbite treatments to determine which treatments are effective. We also planned to perform meta-analyses of the outcomes of individual treatments for which suitable data were available.

MAIN BODY

We performed a systematic review and meta-analyses in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We searched PubMed, Cochrane Trials, and EMBase to identify primary references from January 1, 1900, to June 18, 2022. After eliminating duplicates, we screened abstracts to identify eligible studies containing information on treatment and outcomes of Grade 2 to 4 frostbite. We performed meta-analyses of groups of articles that provided sufficient data. We registered our review in the prospective registry of systematic reviews PROSPERO (Nr. 293,693). We identified 4,835 potentially relevant studies. We excluded 4,610 studies after abstract screening. We evaluated the full text of the remaining 225 studies, excluding 154. Ultimately, we included 71 articles with 978 cases of frostbite originating from 1 randomized controlled trial, 20 cohort studies and 51 case reports. We found wide variations in classifications of treatments and outcomes. The two meta-analyses we performed both found that patients treated with thrombolytics within 24 h had better outcomes than patients treated with other modalities. The one randomized controlled trial found that the prostacyclin analog iloprost was beneficial in severe frostbite if administered within 48 h.

CONCLUSIONS

Iloprost and thrombolysis may be beneficial for treating frostbite. The effectiveness of other commonly used treatments has not been validated. More prospective data from clinical trials or an international registry may help to inform optimal treatment.

Comprehensive treatment of deep frostbite of multiple fingers after trauma: A case report

BACKGROUND

Frostbite is becoming increasingly common in urban environments, and severe cases can lead to tissue loss. The treatment goal is to preserve tissue and function; the sooner appropriate treatment is administered, the more tissue can be saved. However, not every patient with deep frostbite seeks medical care promptly.

CASE SUMMARY

We report the case of a 73-year-old male patient who was lost in the wilderness for 2 d due to trauma and confusion. He experienced deep frostbite on multiple fingers. Treatment should not be discontinued for patients with deep frostbite who present after the optimum treatment timing. Bullae that no longer form (bloody) blisters within 24 h of aspiration should be removed. Mucopolysaccharide polysulfate cream has clinical value in frostbite treatment. The patient was transferred to Chinese Academy of Medical Sciences and Peking Union Medical College Hospital 12 h after being rescued. The patient had contraindications for thrombolysis, the most effective treatment, due to intracranial hemorrhage and presenting past the optimum treatment timing. We devised a comprehensive treatment plan, which involved delayed use vasodilators and high-pressure oxygen therapy at day 49 post-injury. We experimented with mucopolysaccharide polysulfate cream to treat the frostbite. The aim of the treatment was to safeguard as much tissue as possible. In the end, the fingers that suffered from frostbite were able to be partially preserved.

CONCLUSION

The case indicated that patients with severe frostbite who missed the optimal treatment time and had contraindications for thrombolysis could still partially preserve the affected limbs through comprehensive treatment.

Botulinum Toxin A in the treatment of frostbite sequelae - results from a blinded, early-phase, comparative trial

INTRODUCTION

Freezing Cold Injuries (FCI) have been associated with long-term sequelae including vasospasm. The aims of the pilot study are to explore the research methodology and investigate the tolerability and safety of treatment with Botulinum Toxin-A (BTX-A) in FCI Sequelae.

METHODOLOGY

This pilot study tests the logistics, the treatment setting and the follow-up procedure in an early-phase, double-blinded, randomized, controlled trial study-design. The variables in the study were subjective symptoms, peripheral micro-vascularization/rewarming, somatosensory responsiveness, and generic measure of health status.

RESULTS

No major challenges or difficulties were noticed according to the protocol or the study methodology. The monitoring of tolerability and safety of treatment with BTX-A did not reveal any major unwanted and/or adverse reactions among the patients in the pilot study and no challenges occurred during data collection of endpoints. The study revealed an inaccuracy of the 2nd degree FCI diagnosis and uncover a need for relevant and sufficient clinical information for FCI classification.

CONCLUSIONS

This pilot study showed the study methodology with minor adjustments is feasible in a future full-scale clinical trial. The recruitment process needs to be more refined to ensure that the eligible study participants are a homogenous group of FCI patients.

Can iloprost be used for treatment of cold weather injury at the point of wounding in a forward operating environment? A literature review

INTRODUCTION

Cold Weather Injury (CWI) represents a spectrum of pathology, the two main divisions being Freezing Cold Injury (FCI) and Non-Freezing Cold Injury (NFCI). Both are disabling conditions associated with microvascular and nerve injury often treated hours after initial insult when presenting to a healthcarestablishment. Given that iloprost is used for the treatment of FCI, could it be used in a forward operating environment to mitigate treatment delay? Is there a role for its use in the forward treatment of NFCI? This review sought to evaluate the strength of evidence for the potential use of iloprost in a forward operating environment.

METHODS

Literature searches were undertaken using the following question for both FCI and NFCI: in [patients with FCI/NFCI] does [the use of iloprost] compared to [standard care] reduce the incidence of [long-term complications]. Medline, CINAHL and EMBASE databases were searched using the above question and relevant alternative terminology. Abstracts were reviewed before full articles were requested.

RESULTS

The FCI search yielded 17 articles that were found to refer to the use of iloprost and FCI. Of the 17, one referred to pre-hospital treatment of frostbite at K2 base camp; however, this was utilising tPA. No articles referred to pre-hospital use in either FCI or NFCI.

DISCUSSION

Although evidence exists to support the use of iloprost in the treatment of FCI, its use to date has been in hospital. A common theme is delayed treatment due to the challenges of evacuating casualties from a remote location. There may be a role for iloprost in the treatment of FCI; however, further study is required to better understand the risk of its use.

The classification of freezing cold injuries - a NATO research task group position paper

INTRODUCTION

Freezing cold injuries (FCI) are a common risk in extreme cold weather operations. Although the risks have long been recognised, injury occurrences tend to be sparse and geographically distributed, with relatively few cases to study in a systematic way. The first challenge to improve FCI medical management is to develop a common nomenclature for FCI classification. This is critical for the development of meaningful epidemiological reports on the magnitude and severity of FCI, for the standardisation of patient inclusion criteria for treatment studies, and for the development of clinical diagnosis and treatment algorithms.

METHODOLOGY

A scoping review of the literature using PubMed and cross-checked with Google Scholar, using search terms related to freezing cold injury and frostbite, highlighted a paucity of published clinical papers and little agreement on classification schemes.

RESULTS

A total of 74 papers were identified, and 28 were included in the review. Published reports and studies can be generally grouped into four different classification schemes that are based on (1) injury morphology; (2) signs and symptoms; (3) pathophysiology; and (4) clinical outcome. The nomenclature in the different classification systems is not coherent and the discrete classification limits are not evidence based.

CONCLUSIONS

All the classification systems are necessary and relevant to FCI medical management for sustainment of soldier health and performance in cold weather operations and winter warfare. Future FCI reports should clearly characterise the nature of the FCI into existing classification schemes for surveillance (morphology, symptoms, and appearance), identifying risk-factors, clinical guidelines, and agreed inclusion/exclusion criteria for a future treatment trial.

Training videos to prevent cold weather injuries

Cold weather injuries (CWIs) are a challenge during military training, exercises and operations in Arctic conditions. Soldier performance in these challenging conditions depends on protective equipment, knowledge, personal experience, routines, and leadership. Despite the Norwegian Armed Forces' goal of zero freezing cold injuries (FCIs), there has been a persistently high incidence of FCIs among the younger soldiers with an average of 120-150 new FCIs recorded each year. Therefore, an expert working group with representatives from medical, defence and research background was established in 2020. Their task was to develop a communication package to help prevent CWIs among military personnel. Training videos and an updated and improved official website were created with a focus on practical recommendations and advice to prevent CWIs and especially FCIs. Risks, prevention and symptoms of FCIs were emphasised. The main goal of the training videos was to supplement current teaching on guidance for CWI prevention in CWOs to prevent FCIs, but following the advice may prevent non-freezing cold injuries (NFCIs) and hypothermia. This informative paper describes the background, working methods and possible implications of the training videos, which may be a potential way forward to improve cold weather training and operations.

Management of multiple frostbite casualties at a burn center: San Antonio, Texas, 12-20 February 2021

BACKGROUND

Frostbite is an insidious disease that normally affects people of cold climates. Winter Storm Uri, which occurred from February 12-20, 2021, created unique metrological conditions for Texas. It caused prolonged sub-freezing temperatures and led to rolling blackouts, affecting 2.8 million Texans including 300,000 people in San Antonio. We report 13 frostbite patients admitted to one burn center during this event.

OBJECTIVE

We aimed to determine the at-risk population for frostbite, to categorize their injury severity, and to describe their treatment. A secondary aim was to describe the rehabilitation management of these patients.

METHODS

This is a single-center retrospective study. Each patient's injuries were assessed by a topographical grading system. Comparisons were made among those who were admitted to the intensive care unit (ICU), admitted to the progressive care unit (PCU), and treated as outpatients.

RESULTS

Thirteen patients were identified. Ten (76.9 %) considered themselves homeless, and 9 (69.2 %) were directly exposed to the elements. The median delay between time of injury and presentation to a medical facility was 3 days (IQR 1-6). Only 3 patients presented to a medical facility within 24 h. Six (46 %) sustained grade 2 injuries, 2 (15 %) sustained grade 3 injuries, and 5 (38%) sustained grade 4 injuries. Only one patient met criteria to receive tissue plasminogen activator (tPA), which was discontinued due to hematochezia. Patients admitted to the ICU, when compared to patients admitted to the ward, had a longer length of stay (median 73 days v. 12 days, p = 0.0215), and required more amputations at below-the-knee or higher levels (3 v. 0, p-value 0.0442).

CONCLUSION

In a region unaccustomed and perhaps unprepared to deal with winter storms, the population is particularly vulnerable to frostbite. Lack of awareness of frostbite injuries likely led to the delay in the presentation of patients, which prevented the timely use of tPA. Increasing public awareness may increase readiness.

Heat, Cold, and Environmental Emergencies in Athletes

With the increase in outdoor events, there is an inevitable rise in climate-related environmental emergencies. Heat exposure can place athletes at risk for life-threatening heatstroke which requires emergent diagnosis and rapid in-field management. Cold exposure can lead to hypothermia, frostbite, and other nonfreezing injuries that require prompt evaluation and management to minimize morbidity and mortality. Altitude exposure can lead to acute mountain sickness or other serious neurologic or pulmonary emergencies. Finally, harsh climate exposure can be life-threatening and require appropriate prevention and event planning.

Thermal Injuries Occurring to the Foot: A Review

Thermal injuries are one of the most common injuries in both civilian and combat scenarios. The importance of clinical determination of burn and frostbite injuries and treatment involves understanding the pathophysiology and mechanisms of these injuries while continually reviewing literature and studying new treatment modalities. This present review examines the (1) epidemiology, (2) etiology, (3) pathophysiology and classification, and (4) treatment of thermal injuries occurring to the foot. In addition to the paucity of new literature and studies on thermal injury, this is the first review, to the best of our knowledge, to examine the management of thermal injuries occurring to the foot.

The effect of stromal vascular fraction in an experimental frostbite injury model

BACKGROUND

Despite current treatment modalities, frostbite remains an injury with a poor prognosis which may cause functional morbidities. Several experimental and clinical studies have demonstrated that stromal vascular fraction is an autologous mixture, which can improve wound healing and vasculogenesis. The aim of this study was to show the beneficial effects of stromal vascular fraction on experimental frostbite healing.

MATERIAL AND METHODS

Stromal vascular fraction (SVF) was harvested from 5 rats after excision of the inguinal fat pads. Another 20 rats were separated into 2 groups of 10 as the SVF group and the control group. A frostbite injury was created on each rat using a cryoprobe frozen with liquid nitrogen (-196 °C). SVF was applied to the SVF group and phosphate-buffered saline to the control group. All injections were performed subcutaneously within the frostbite injury area. Biopsies were performed on days 5 and 14 for histopathological and immunochemical evaluations. The tissue perfusion rates of both groups were assessed on day 14 using indocyanine green angiography (SPY system).

RESULTS

The increase in mean tissue perfusion was 373.3% ( ± 32.1) in the SVF group and 123.8% ( ± 16.3) in the control group (p < 0.001). The macroscopic wound reduction rates of the SVF and control groups were 25.5% ( ± 19.1) and 18.0% ( ± 5.9), respectively on day 5%, and 78.2% ( ± 9.2) and 57.3% ( ± 16.7) on day 14 (p = 0.007; p = 0.003). Acute inflammation and the fibrosis gradient were significantly decreased in the SVF group compared to the control group (p = 0.004, p = 0.054 respectively on day 14). Granulation tissue amount, re-epithelialization score and neovascularization were significantly increased in the SVF group (p = 0.006, p = 0.010 and p = 0.021, respectively on day 14).

CONCLUSIONS

The study results demonstrated that SVF increases frostbite wound healing by increasing tissue perfusion rate, neovascularization and re-epithelialization, and modulating acute inflammation and fibrosis.

Frostbite of The Extremities - Recognition, Evaluation and Treatment

OBJECTIVES

Frostbite refers to the freezing of body tissue which is caused by prolonged exposure to cold temperatures and results in tissue destruction. Tissue damage is due to both immediate cold-induced cell death and the more gradual development of localized inflammatory processes and tissue ischemia. A detailed treatment plan based on the current UpToDate literature is needed to decrease morbidity and mortality rates.

METHODS

The United States National Library of Medicine (PubMed/Medline), EMBASE, Web of Science, and the Cochrane Database of Systematic Reviews were systematically searched to identify publications relevant to this review.

CONCLUSION

In this review, we present the current knowledge on the diagnosis and treatment of frostbite injuries. We then provide an extended and detailed treatment plan, from first aid in the field to treatment of short and long-term complications .

Frostbite in hot climates of Central Asia: retrospective analysis of the microflora of wound and antibiotic therapy

The problem of deep frostbites belongs to one of the most complex in surgery. Treatment of such victims is very prolonged, expensive, requiring crippling operations resulting in disability. The purpose of this present study is of etiological structure of the wound microflora and its tolerance to antibacterial preparations in patients with cold injury in the regions with warm climate of severe degree. 57 microbiological investigations of wound secretions in 38 patients with severe cold injury treated in our Burn Department of RSCUMA, Samarkand, Uzbekistan had been carried out. Microflora of wounds in patients who suffered from cold injury is characterized by polyetiology and is presented by gramnegative (49.5%) and grampositive (50.5%) microorganisms. There are Pseudomonas aeruginosa (17.9%). Among gramnegative microorganisms. In this context sensitivity to preparations owing activity to Pseudomonas aeruginosa-Ceftazidim, Ceferin and Amycacin makes 48.8%, 54.5% and 81.3% accordingly. Prevailing flora of grampositive is Staphylococcus aureus (26.3% of agents), of which 60% makes MRSA. High resistance to Ciprofloxacin (66.6%), Erythromycin (52.5%) and Lincomycin (44.4%) is noted. The investigations give evidence that ABT in patient with severe frostbites is a serious problem and needs well-ground approach in prescribing antibacterial preparations.

A Tibetan adolescent girl suffered frostbite on the journey of pilgrimage: A case report

Frostbite in Southwestern China has been overlooked due to its low incidence, relatively mild temperature and lack of literature published before. However, it needs to be further studied for religious diversity and distinct geomorphology. In this article, we reported an 18-year-old Tibetan girl who suffered from blizzard attack during pilgrimage. Her feet and several fingers showed mummified gangrene upon physical examination with poor movement. She was diagnosed with 3rd to 4th degree of frostbite. The girl was given oral ibuprofen, debridement and other regular treatment daily, but she was eventually amputated due to insufficient thrombolytic management in primary hospital, delayed informing consent in the referral hospital and ethnic conflict between religion and guidelines. This case enriched the experience of managing complex frostbite in Tibetan population and alarms that efforts should be integrated to protect pilgrims and mountaineers in the Tibetan region.

Frostbite injury: an unknown risk when using nitrous oxide as a party drug

In recent years nitrous oxide has become a popular party drug. Large cylinders filled with nitrous oxide are used to fill balloons for recreational use. We present two patients with severe third-degree cold burns on their thighs after clamping a large cylinder between their legs while filling balloons. During filling, large amounts of nitrous oxide are inhaled, which causes the pain to be numbed. As nitrous oxide is discharged from the cylinder, the cylinder becomes ice cold. Due to direct contact with the icecold cylinder and numbness, third-degree frostbite wounds occur. In both cases presented, the burn wounds had to be debrided and treated with split-thickness skin transplants. Awareness is needed as at first presentation as the burns look superficial, but can rapidly develop into third-degree burn wounds. Close follow-up and aggressive treatment is necessary to prevent infections and to regain a good functional outcome of the affected limb.

Clinical utilization of a sous vide device in the acute rewarming of frostbitten extremities

The current standard of care for acute frostbite rewarming is the use of a circulating warm water bath at a temperature of 37 °C to 39 °C. There is no standardized method to achieve this. Manual management of a warm water bath can be inefficient and time consuming. This case describes the clinical use of a sous vide cooking device to create and maintain a circulating warm water bath to rewarm acute frostbite. A 34 year-old male presented to the emergency department with acute frostbite. Each of the patient's feet were placed in a water bath with a sous vide device attached to the side of the basin and set to 38 °C. Temperatures were recorded every 2 m from 2 thermometers. Once target temperature was achieved, the extremities were rewarmed for 30 m. The water baths required an average of 25 m to reach target temperature and maintained the target temperature within ±1 °C for the duration of the rewarming. The extremities were clinically thawed in one session and there were no adverse events. The patient was seen by plastic and vascular surgery and admitted to the hospital for conservative management. He was discharged on hospital day 3 and did not require any amputations. A sous vide device can be used clinically to heat and maintain a water bath and successfully rewarm frostbitten extremities in one 30 m cycle. No adverse events were reported and providers rated this as a convenient method of water bath management.

Extracellular vesicles from human hepatic progenitor cells accelerate deep frostbite wound healing by promoting fibroblasts proliferation and inhibiting apoptosis

Frostbites are cold tissue damages frequently observed at high altitudes and under extremely cold conditions. Though their incidence rate is low, the resulting impact in affected patients can be very serious, often leading to amputations. Clinical management and the prediction of outcome can be of utmost importance to frostbite patients. A possible use of stem cell-derived extracellular vesicles (EVs) has been suggested for cutaneous wound healing and we, therefore, tested their use for the treatment of deep frostbite wound. To this end, the impacts of hHPC-derived EVs were evaluated in an in vivo animal model comprising of Kunming female mice as well as studied in vitro for the mechanism. We first characterized the EVs and these hHPC-derived EVs, when applied to treat frostbite wounds, accelerated wound healing in the in vivo animal model, as assessed by wound closure, re-epithelization thickness, collagen density and the expression of Collagen I and α-SMA. The proliferation and migration of human skin fibroblasts was also found to be increased by EVs in the in vitro experiments. The H₂O₂-induced apoptosis cell model, established to simulate the post-frostbite injury, was inhibited by EVs, with concomitant increase in the expression of Bcl-2 and decreased expression of Bax, further confirming the findings. Our novel results indicate that the application of EVs might be a promising strategy for deep frostbite wound healing.

A digital tool for prevention and management of cold weather injuries-Cold Weather Ensemble Decision Aid (CoWEDA)

This paper describes a Cold Weather Ensemble Decision Aid (CoWEDA) that provides guidance for cold weather injury prevention, mission planning, and clothing selection. CoWEDA incorporates current science from the disciplines of physiology, meteorology, clothing, and computer modeling. The thermal performance of a cold weather ensemble is defined by endurance times, which are the time intervals from initial exposure until the safety limits are reached. These safety limits correspond to conservative temperature thresholds that provide a warning of the approaching onset of frostbite and/or hypothermia. A validated six-cylinder thermoregulatory model is used to predict human thermal responses to cold while wearing different ensembles. The performance metrics, model, and a database of clothing properties were integrated into a user-friendly software application. CoWEDA is the first tool that allows users to build their own ensembles from the clothing menu (i.e., jackets, footwear, and accessories) for each body region (i.e., head, torso, lower body, hands, feet) and view their selections in the context of physiological strain and the operational consequences. Comparison of predicted values to skin and core temperatures, measured during 17 cold exposures ranging from 0 to -40°C, indicated that the accuracy of CoWEDA prediction is acceptable, and most predictions are within measured mean ± SD. CoWEDA predicts the risk of frostbite and hypothermia and ensures that a selected clothing ensemble is appropriate for expected weather conditions and activities. CoWEDA represents a significant enhancement of required clothing insulation (IREQ, ISO 11079) and wind chill index-based guidance for cold weather safety and survival.

Frostbite: Current status and advancements in therapeutics

Frostbite is a severe ischemic injury which occurs due to the tissue vascular damage after sub-zero temperature tissue exposure. Deep frostbite can result in necrosis and may need amputation of affected tissue. Though a serious injury, it is not very well understood, and further scientific exploration is needed. This work explores the current understanding of the pathophysiology of frostbite. We reviewed the current status of the diagnostics, the drugs, the therapies and the surgical practices for prevention and management of frostbite. Advances in nanotechnology and drug delivery had improved the therapeutic outcomes significantly. This review also explored the latest advancements and researches done for development of newer therapeutics and diagnostics for frostbite care.

[Interpretation of 2019 edition of Wilderness Medical Society practice guidelines for prevention and treatment of frostbite]

The Wilderness Medical Society updated and published the Wilderness Medical Society practice guidelines for the prevention and treatment of frostbite in July 2019. The guidelines provide evidence-based recommendations for the prevention and treatment of frostbite, mainly including pathophysiology, classification, prevention, and treatment of frostbite. This paper focuses on the interpretation of the guidelines, aiming at making clinical medical staff understand the new progress of frostbite treatment and providing reference for clinical practice.

Severe frostbite complication after cryolipolysis: A case report

This case report describes a full-thickness frostbite complication following cryolipolysis for subcutaneous fat reduction performed in a non-medical esthetic clinic. The deep and large abdominal wound (15 × 12 cm) required hospitalization and multiple surgical debridement before a two-step direct closure. Even though cryolipolysis is considered as a non-invasive and safe technique to reduce local adiposity, it could present some side-effects and complications. Health-care professionals should be aware of these risks and inform their patients about its potential sequelae.

Frostbite injuries: independent predictors of outcomes

Objectives

Frostbite injuries are important causes of morbidity and mortality after trauma. Epidemiology, injury patterns, and outcomes after frostbite among patients presenting to trauma centers are incompletely defined. The purpose of this study was to delineate patient demographics, clinical characteristics, and independent predictors of outcomes after frostbite.

Material and Methods

Patients with frostbite injury were identified from the National Trauma Data Bank (NTDB) (2007-2014). Demographics, clinical/injury data, and outcomes were collected. Patients were dichotomized into study groups based on intensive care unit (ICU) admission. Univariate analysis was performed with the Mann-Whitney U, Fisher's exact, or Chi-Square test as appropriate. Multivariate analysis using logistic regression determined independent predictors of outcomes.

Results

Over the study period, 241 patients were identified. Median body temperature on admission was 36.3⁰C (IQR 33.4-36.7). Mortality was 3% (n= 7). ICU admission was required in 101 (42%) patients and 48 (20%) underwent surgical intervention. On multivariate analyses, mortality was predicted by lower admission GCS (p= 0.027) and amputation by higher HR (p= 0.013). Need for ICU admission was predicted by older age (p= 0.010), male gender (p= 0.040), higher HR (p= 0.031) and ISS (p <0.001), and lower GCS (p= 0.001). Prolonged hospital LOS was predicted by higher heart rate (p <0.001) and ISS (p <0.001).

Conclusion

Frostbite injuries are uncommon but can necessitate surgical intervention and cause mortality. Lower GCS and higher heart rate, but not body temperature, portend poor outcomes. These findings can be used to triage patients appropriately upon admission and to better inform prognosis after frostbite injuries.

Protocoled thrombolytic therapy for frostbite improves phalangeal salvage rates

Background

Frostbite is a cold injury that has the potential to cause considerable morbidity and long-term disability. Despite the complexity of these patients, diagnostic and treatment practices lack standardization. Thrombolytic therapy has emerged as a promising treatment modality, demonstrating impressive digit salvage rates. We review our experience with thrombolytic therapy for severe upper extremity frostbite.

Methods

Retrospective data on all frostbite patients evaluated at our institution from December 2017 to March 2018 was collected. A subgroup of patients with severe frostbite treated with intra-arterial thrombolytic therapy (IATT) were analysed.

Results

Of the 17 frostbite patients treated at our institution, 14 (82%) were male and the median age was 31 (range: 19–73). Substance misuse was involved in a majority of the cases (58.8%). Five (29.4%) patients with severe frostbite met inclusion criteria for IATT and the remaining patients were treated conservatively. Angiography demonstrated a 74.5% improvement in perfusion after tissue plasminogen activator thrombolysis. When comparing phalanges at risk on initial angiography to phalanges undergoing amputation, the phalangeal salvage rate was 83.3% and the digit salvage rate was 80%. Complications associated with IATT included groin hematoma, pseudoaneurysm and retroperitoneal hematoma.

Conclusions

Thrombolytic therapy has the potential to greatly improve limb salvage and functional recovery after severe frostbite when treated at an institution that can offer comprehensive, protocoled thrombolytic therapy. A multi-center prospective study is warranted to elucidate the optimal treatment strategy in severe frostbite.

[Effects of recombinant human granulocyte macrophage colony stimulating factor gel on treatment of full-thickness frostbite wounds on foot and hand]

Objective: To explore the effects of recombinant human granulocyte macrophage colony stimulating factor (rhGM-CSF) gel on treatment of thefull-thickness frostbite wounds on foot and hand. Methods: From November 2013 to April 2017, a total of 45 patients of 71 full-thickness frostbite wounds on foot and hand meeting the inclusion criteria were admitted to the First Hospital of Jilin University and the prospective randomized controlled study was done. The patients were divided into rhGM-CSF group of 24 patients with 35 wounds and control group of 21 patients with 36 wounds according to the random number table. There were 20 males and 4 females, aged (38±13) years among patients in rhGM-CSF group, and there were 19 males and 2 females, aged (36±14) years among patients in control group. Patients in 2 groups were performed with the same systemic treatment of rewarming, anti-inflammation, pain relief, anti-infection, anti-coagulation, and thrombolysis. Wounds of patients in rhGM-CSF group and control group were respectively treated with rhGM-CSF gel and aloe vera gel for external usage with 10 mg for every square centimeter and dressing change once every 24 hours, until wounds healed completely. The wound inflammatory response was scored on treatment day (TD) 1, 3, 7, 14, wound secretion was collected for bacteria culture and positive bacteria detection rate was calculated before treatment and on TD 6 and 12, adverse drug reaction after drug use was observed, and the complete wound healing time was recorded. Data were processed with Fisher's exact probability test, analysis of variance for repeated measurement, t test, and Bonferroni correction. Results: The scores of wound inflammatory response of patients in 2 groups on TD 1 and 3 were close (t=0.37, 2.93, P>0.05). The scores of wound inflammatory response of patients on TD 7 and 14 in rhGM-CSF group were significantly higher than those in control group (t=5.77, 5.83, P<0.01). The results of bacteria culture of wound secretion of patients in 2 groups before treatment were negative. The positive bacteria detection rates of wound secretion of patients in rhGM-CSF group on TD 6 and 12 were 5.71% (2/35) and 22.86% (8/35), which were slightly lower than 13.89% (5/36) and 30.56%(11/36) in control group respectively, but there was no significantly statistical difference (P>0.05). No adverse drug response occurred in patients in rhGM-CSF group, while 1 patient in control group had adverse drug response, with symptoms of redness and swelling of wounds and patchy erythema on skin around wounds, which were alleviated by irrigating with normal saline. The complete wound healing time of patients in rhGM-CSF was (12.3±0.5) d, which was significantly shorter than (16.5±0.8) d in control group (t=24.89, P<0.05). Conclusions: The topical rhGM-CSF gel has effects of shortening time of wound healing and reducing inflammatory response of wound on treatment of full-thickness frostbite wounds on foot and hand, which is safe in clinical application.

[Minor similarities and major differences between cold injury and burn injury]

Cold injury is very damaging. This article summarizes the mechanism, types, and rehabilitation of cold injury, focusing on the degree and clinical treatment of frostbite. Frostbite can mainly cause damage of microcirculation and capillary structure, while burn injury can mainly cause damage of cutaneous tissues. Based on this, the key point of management of frostbite is to improve microcirculation and appropriate rewarming, while that of burn injury is wound repair. Up to date, the rate of amputation caused by frostbite is still high, and the rehabilitation for sequela caused by frostbite remains a big challenge in modern medicine. It is worth paying more attention to.

Finger- and toe-temperature responses to local cooling and rewarming have limited predictive value identifying susceptibility to local cold injury-a cohort study in military cadets

The purpose was to evaluate whether a cold-water immersion test could be used to identify individuals susceptible to local cold injuries (LCI). Sixty-five healthy non-injured (N-I) subjects, and fifteen subjects, who were tested either prior to or after a LCI, sequentially immersed one hand and one foot, in 8 °C water for 30 min (CWI phase); this was followed by 15 min of spontaneous rewarming (RW phase). The LCI group showed a lower toe temperature during the CWI phase, and a lower maximum RW temperature of the fingers than the N-I group. However, digit temperatures during the CWI and RW phases exhibited low predictive values for LCI, e.g. results implied that to identify 80% of the LCI subjects, 34-78% of the N-I subjects would also be excluded. Thus, the results suggest that, in practice, hand or foot cold-water immersion tests cannot be used to identify individuals at high risk of LCI.

Barriers to frostbite treatment at an academic medical center

The treatment of frostbite injuries has undergone a radical change over the past decade with a shift from supportive therapy and observation towards early and aggressive medical intervention with thrombolytics and vasodilators. Institutions that have implemented evidence-based protocols have significantly decreased their amputation rates (Bruen et al., 2007; Lindford et al., 2017a; Twomey et al., 2005). We present the case of a middle-aged male treated for frostbite of multiple fingers on both hands. Because there was no treatment protocol at our institution, there were multiple delays in the patient's care including imaging and initiation of intravenous (IV) prostanoids. This case illustrates the deleterious effects of delays in treatment and strongly suggests that all facilities located in areas of cold exposure should have protocols in place for such an occurrence.

A novel approach to rapid rewarming of a frostbitten extremity: The sous vide method

BACKGROUND

Rapid rewarming of an acutely frostbitten extremity has been the standard treatment for nearly 60 years, however, there are no existing practical recommendations to create a warm water bath. Our study describes a novel approach to rapid rewarming using a sous vide cooking device to create and maintain a circulating warm water bath at a desired set temperature.

METHODS

A series of in vitro experiments were performed to assess the efficacy of different methods of maintaining constant water temperature while rapidly rewarming a simulated frostbitten extremity (frozen pig's foot). An Anova Sous Vide Precision Cooker® was attached to a 5 gallon bucket and used to circulate and maintain the water at 104 °F while rewarming a frozen pig's foot. This method was compared to manual exchange of water to maintain the temperature at 104 °F and to a control with no water exchanged. During each experiment, the temperature of the water was recorded every 2 min and the pliability of the pig's foot was assessed after 30 min.

RESULTS

The sous vide method maintained circulating water at a constant temperature of 104 °F for 30 min. At 30 min the frozen pig's foot was warm, soft, and pliable. The manual method resulted in temperature fluctuations requiring frequent large volume water exchanges. When no water was exchanged, the water cooled quickly and the pig's foot remained partially frozen.

CONCLUSION

Sous vide rewarming is a novel method that easily creates and maintains a warm water bath ideal for rapid rewarming of a frostbitten extremity.

[Advances in the research of transcatheter arterial thrombolysis for severe frostbite therapy]

Severe frostbite (grade Ⅲ to Ⅳ) is a common disease accompanied with high disability rate in cold regions, especially for military training and disaster events in cold regions. The treatment of severe frostbite mainly includes rapid rewarming in the early stage and amputation in the later stage; while the damage of vascular endothelial cells, microvascular thrombosis, and decreased tissue perfusion secondary to severe frostbite are important factors affecting prognosis. Transcatheter arterial thrombolysis is a new technique for the treatment of severe frostbite. It has the advantages of minimally invasive, high safety, and significantly reduced amputation rate. We reviewed the advances in the research of transcatheter arterial thrombolysis for the treatment of severe frostbite.

Raynaud's phenomenon in Northern Sweden: a population-based nested case-control study

The aim of this study was to determine the association between individual and external exposure factors, and the reporting of Raynaud's phenomenon, with or without concomitant cold sensitivity. In a population-based nested case-control study, cases with Raynaud's phenomenon (N = 578), and matched controls (N = 1156), were asked to respond to a questionnaire focusing on different risk factors. Univariate and multiple conditional logistic regression were performed. Analyses were stratified according to whether the cases reported cold sensitivity or not. In total, 1400 out of 1734 study subjects answered the questionnaire (response rate 80.7%). In the final multiple model, the factor with the strongest association to Raynaud's phenomenon, with and without cold sensitivity, was previous frostbite affecting the hands (OR 12.44; 95% CI 5.84-26.52 and OR 4.01; 95% CI 1.78-9.01, respectively). Upper extremity nerve injury was associated to reporting Raynaud's phenomenon and cold sensitivity (OR 2.23; 95% CI 1.29-3.85), but not Raynaud's phenomenon alone. Reporting any exposure to hand-arm vibration or cumulative cold exposure was significant in univariate analyses for cases with both Raynaud's phenomenon and cold sensitivity, but not in the multiple model. Raynaud's phenomenon is strongly associated to previous cold injury, with a larger effect size among those who also report cold sensitivity. The fact that only upper extremity nerve injury differed significantly between case groups in our multiple model offers additional support to the neural basis for cold sensitivity.

Pediatric frostbite: A 10-year single-center retrospective study

OBJECTIVE

To describe frostbite (freezing cold injured tissue) in children and intrinsic (psychological and behavioral) and extrinsic (meteorological and safety hazard) factors related to the injury.

METHODS

Retrospective chart review of children <18 years old referred to a regional pediatric hospital for frostbite, to determine the demographics, environment, and risk factors related to injuries.

RESULTS

47 patients met the inclusion criteria. Median age was 15 years (IQR 12-16). All injuries occurred between November and March. 49% were admitted to the hospital and frostbite was associated with use of alcohol (53%), cigarettes (34%), marijuana (23%), and symptoms of depression (with and without suicidal ideation) (32%). Frostbite injury treated with conservative wound management presented at <-6°C and injury that underwent surgical procedures occurred at temperatures ≤-23°C (p=0.001). Longer exposure duration also significantly increased the likelihood of a surgical procedure (p<0.001). Intoxication and lack of supervision were two common factors, with lack of supervision at time of injury most common among patients 0-12 years (64%), and intoxication most common among patients ages 13-17 (61%).

CONCLUSION

Frostbite injuries in children begins at temperatures <-6°C; with risk of tissue loss increasing at temperatures below -23°C. Lack of supervision and intoxication are major risk factors for frostbite in children. Two-thirds of younger children were unsupervised, whereas intoxication was frequently related to frostbite in adolescents. Both of these factors can be addressed through an education-based prevention program.

Blizzards and Range Cattle: Management Before, During, and After the Storm

Numerous factors contribute to the outcome and recovery for range cattle affected by blizzard. Consequences and impact on the producer depend on the timing of the storm relative to the herd's production cycle, access to shelter, duration and intensity of the storm, and post-storm emergency management. Critical planning efforts by the producer include clear animal identification methods, identification of sheltering options, and consideration of animal indemnity and insurance requirements. Including range animals in local and state disaster planning efforts facilitates response and recovery efforts. Response efforts must include understanding of postincident animal behavior concerns and producer and responder mental health.

Cold sensitivity and associated factors: a nested case-control study performed in Northern Sweden

Purpose

To identify factors associated with the reporting of cold sensitivity, by comparing cases to controls with regard to anthropometry, previous illnesses and injuries, as well as external exposures such as hand–arm vibration (HAV) and ambient cold.

Methods

Through a questionnaire responded to by the general population, ages 18–70, living in Northern Sweden (N = 12,627), cold sensitivity cases (N = 502) and matched controls (N = 1004) were identified, and asked to respond to a second questionnaire focusing on different aspects of cold sensitivity as well as individual and external exposure factors suggested to be related to the condition. Conditional logistic regression analyses were performed to determine statistical significance.

Results

In total, 997 out of 1506 study subjects answered the second questionnaire, yielding a response rate of 81.7%. In the multiple conditional logistic regression model, identified associated factors among cold sensitive cases were: frostbite affecting the hands (OR 10.3, 95% CI 5.5–19.3); rheumatic disease (OR 3.1, 95% CI 1.7–5.7); upper extremity nerve injury (OR 2.0, 95% CI 1.3–3.0); migraines (OR 2.4, 95% CI 1.3–4.3); and vascular disease (OR 1.9, 95% CI 1.2–2.9). A body mass index ≥ 25 was inversely related to reporting of cold sensitivity (0.4, 95% CI 0.3–0.6).

Conclusions

Cold sensitivity was associated with both individual and external exposure factors. Being overweight was associated with a lower occurrence of cold sensitivity; and among the acquired conditions, both cold injuries, rheumatic diseases, nerve injuries, migraines and vascular diseases were associated with the reporting of cold sensitivity.

A new treatment for frostbite sequelae; Botulinum toxin

Frostbite sequelae are a relevant occupational injury outcome for soldiers in arctic environments. A Caucasian male soldier suffered frostbite to both hands during a military winter exercise. He developed sensory-motor disturbances and cold hypersensitivity. Angiography and thermography revealed impaired blood flow while Quantitative Sensory Testing indicated impaired somato-sensory nerve function. Two years after the initial event, he received an off label treatment with Botulinum toxin distributed around the neurovascular bundles of each finger. After treatment, cold sensitivity was reduced while blood flow and somato-sensory nerve function improved. The successful treatment enabled the soldier to successfully pursue his career in the army.

[Physical and chemical emergencies in dermatology]

Physical and chemical emergencies are often caused by household or work accidents. Regardless of the medical field and outside specialized clinics, the physician may be confronted with the situation for first or secondary care. The identification of the causing agent and a rapid assessment of the extent and severity of the tissue damage are essential to initiate early transfer to a specialized burn clinic. Grade 2b tissue damage is usually surgically treated. Smaller and superficial injuries can often be conservatively treated. Even supposedly safe and over-the-counter medicines can also lead to serious tissue damage.

Non-Melanoma Skin Cancers at Sites of Previous Frostbite: Case Report and Review

The association between ultraviolet radiation exposure and skin cancer is well established. Limited studies have reported an association between frostbite and the development of non-melanoma skin cancer but evidence for a proven link is insufficient and possible carcinogenic mechanisms have not been fully explored. In this report, 3 cases of non-melanoma skin cancer (1 case of basal cell carcinoma and 2 cases of squamous cell carcinoma of the skin) which developed at a site of previous frostbite caused by exposure to extremely cold temperatures in Astana, the capital city of Kazakhstan, are described.

Analytical expressions for estimating endurance time and glove thermal resistance related to human finger in cold conditions

Frostbite is considered the severest form of cold injury and can lead to necrosis and loss of peripheral appendages. Therefore, prediction of endurance time of limb's tissue in cold condition is not only necessary but also crucial to estimate cold injury intensity and to choose appropriate clothing. According to the previous work which applied a 3-D thermal model for human finger to analyze cold stress, in this study, an expression is presented for endurance time in cold conditions to prevent cold injury. A formula is also recommended to select a proper glove with specific thermal resistance based on the ambient situation and cold exposure time. By employing linear extrapolation and real physical conditions, the proposed formulas were drawn out from numerical simulation. Analytical results show good agreement with numerical data. The used numerical data had been also validated with experimental data existed in the literature. Furthermore, the effect of different parameters such as glove thermal resistance and ambient temperature is investigated analytically.

Intra-arterial Thrombolysis for Extremity Frostbite Decreases Digital Amputation Rates and Hospital Length of Stay

PURPOSE

To report outcomes of intra-arterial thrombolysis versus non-thrombolytic management of severe frostbite with respect to digital amputation rates and hospital length of stay (LOS).

MATERIALS AND METHODS

Seventeen patients with severe frostbite were identified from 2000 to 2017. Eight (47%) patients with mean age of 40 years underwent intra-arterial thrombolysis and served as the treatment group. Nine (53%) patients with mean age of 53 years received non-thrombolytic management and served as the control group. 2/8 (25%) treatment and 3/9 (33%) control patients had underlying vascular comorbidities (p = 0.25). Number of digits at risk, duration of thrombolysis, thrombolytic agents used, digits amputated, hospital LOS, and complications were recorded.

RESULTS

Seven upper and nine lower extremities for a total of 80 digits were at risk in the treatment cohort. Eight upper and 12 lower extremities for a total of 100 digits were at risk in the control group. Mean duration of thrombolysis was 26 h. All treatment patients received tissue plasminogen activator in addition to systemic heparin. 4/16 (25%) limbs received intra-arterial alprostadil, 2/16 (13%) received nitroglycerin, and 2/16 (13%) received nicardipine. 12/80 (15%) treatment digits and 77/100 (77%) control digits required amputation (p = 0.003). Average hospital LOS was 14 days in the treatment group and 38 days in the control group (p = 0.011). No major complications occurred in the treatment group; however, 2/9 (22%) patients in the control group required extended hospitalizations secondary to amputation complications.

CONCLUSIONS

Intra-arterial thrombolysis reduces digital amputation rates and hospital LOS in the setting of severe frostbite.

Cold Injuries

New treatments of frostbite have led to unprecedented salvage of extremities including fingers and toes. Success is predicated on prompt institution of time-sensitive protocols initiated soon after rewarming, particularly the use of thombolytics. Unfortunately, in the urban setting, most patients are not candidates for these treatment modalities. Triple-phase bone scans have allowed for early determination of devitalized parts that need amputation. Reconstructive surgical techniques are typically used to salvage limb length in these devastating injuries.

Neurovascular hand symptoms in relation to cold exposure in northern Sweden: a population-based study

PURPOSE

To describe the self-reported ambient cold exposure in northern Sweden and to relate the level of cumulative cold exposure to the occurrence of sensory and vascular hand symptoms. We hypothesize that cold exposure is positively related to reporting such symptoms.

METHODS

A questionnaire about cold exposure and related symptoms was sent out to 35,144 subjects aged 18-70 years and living in northern Sweden.

RESULTS

A total of 12,627 out of 35,144 subjects returned the questionnaire (response rate 35.9%). Subjects living in the rural alpine areas reported more extensive cold exposure both during work and leisure time compared to the urbanized coastal regions. Frostbite in the hands was present in 11.4% of men and 7.1% of women, cold sensitivity was present in 9.7 and 14.4%, and Raynaud's phenomenon was present in 11.0% of men and 14.0% of women. There was a positive association between cumulative cold exposure and neurovascular hand symptoms.

CONCLUSION

The present study demonstrates that the cold environment in northern Sweden might be an underestimated health risk. Our hypothesis that cold exposure is positively related to reporting of neurovascular hand symptoms was supported by our findings. In addition, such symptoms were common not only in conjunction with an overt cold injury. Our results warrant further study on pathophysiological mechanisms and suggest the need for confirmatory prevalence studies to support national public health planning.

A 3D thermal model to analyze the temperature changes of digits during cold stress and predict the danger of frostbite in human fingers

The existing computational models of frostbite injury are limited to one and two dimensional schemes. In this study, a coupled thermo-fluid model is applied to simulate a finger exposed to cold weather. The spatial variability of finger-tip temperature is compared to experimental ones to validate the model. A semi-realistic 3D model for tissue and blood vessels is used to analyze the transient heat transfer through the finger. The effect of heat conduction, metabolic heat generation, heat transport by blood perfusion, heat exchange between tissues and large vessels are considered in energy balance equations. The current model was then tested in different temperatures and air speeds to predict the danger of frostbite in humans for different gloves. Two prevalent gloves which are commonly used in cold climate are considered for investigation. The endurance time and the fraction of necrotic tissues are two main factors suggested for obtaining the response of digit tissues to different environmental conditions.

The use of intravenous tPA for the treatment of severe frostbite

OBJECTIVE

tPA and anticoagulation for treatment of severe frostbite have been reported suggesting differences in imaging techniques, route of tPA administration and management of patients after tPA infusion. This is a report of our results following a protocol of Tc-99m scanning, intravenous tPA administration, followed by either systemic anticoagulation or antiplatelet therapy.

METHODS

Patients admitted to our burn center between February 13, 2015 and February 13, 2016 for frostbite who met inclusion criteria were treated with Tc-99m scan and intravenous tPA followed by systemic anticoagulation or antiplatelet therapy. Inclusion criteria included rewarming had not started more than 24h prior to the scan and no contraindications to the use of tPA.

RESULTS

Fifteen patients met inclusion criteria and 12 were treated according to the protocol. Nine received scans with 2 showing normal perfusion. Seven displayed perfusion defects and received intravenous tPA. Five recovered fully after tPA. Two who showed improved but abnormal scans after tPA experienced bleeding complications necessitating stopping heparin/Coumadin. Those two went on to partial amputation of digits.

CONCLUSION

The use of intra-arterial or intravenous tPA along with angiography or Tc-99m scanning followed by systemic anticoagulation or antiplatelet therapy may be beneficial to patients suffering frostbite.