The value of technetium 99 scintigraphy in the prognosis of amputation in severe frostbite injuries of the extremities: A retrospective study of 92 severe frostbite injuries

Patient and treatment characteristics that predict symptom resolution and limb amputation in patients with frostbite

PURPOSE

To describe imaging and treatment received by frostbite patients and determine characteristics that predict symptom resolution and limb amputation.

MATERIALS AND METHODS

This retrospective study included 174 adult patients with acute frostbite at a single institution from May 1, 2004, to August 31, 2019. Demographics, frostbite classification, symptoms present and imaging received at presentation, treatment received, and dates of symptom resolution, were collected.

RESULTS

Patients most commonly received no imaging (60.3 %), followed by x-ray (28.7 %). The most common treatments were debridement (53.4 %), none (24.1 %), other (15.5 %), antibiotics (12.6 %), and tPA (8.0 %). Of 17 who had a limb amputated, the number of affected extremities (p = 0.003), frostbite degree (p = 0.004), and baseline symptoms of abnormal skin color change (p = 0.028), absence of pulse (p = 0.021), swelling (p = 0.010), and necrosis/gangrene (p = 0.002) significantly increased the risk of limb amputation. tPA lowered the risk of limb amputation with an estimated hazard ratio of 0.193 (p = 0.003).

DISCUSSION

Patients received a variety of treatments and imaging for frostbite. tPA was not often used in this study but could play a larger role in the treatment of frostbite since it was shown to lower the risk of limb amputation.

Frostbite in the Pediatric Population: A Comprehensive Review and a Prospective Canadian Survey

INTRODUCTION

Frostbite in the pediatric population, where skeletal maturity has not been achieved, can have important repercussions on subsequent growth. Yet, the optimal management of frostbite injuries in children remains vague. This review aims to summarize the current evidence for frostbite management in children and understand Canadian practice trends on this topic.

METHODS

A review using Medline, Scopus, Web of Science, and gray literature was performed to identify relevant literature on the clinical manifestations, diagnostic methods, and treatment options in pediatric frostbite. An online survey was sent to plastic surgeons through the Canadian Society of Plastic Surgeons (CSPS) mailing list to further identify national practices and trends for pediatric frostbite management.

RESULTS

A total of 109 articles were reviewed. No article provided a specific algorithm for pediatric frostbite, with existing recommendations suggesting the use of adult guidelines for treating children. Our survey yielded 9 responses and highlighted the rarity of pediatric frostbite cases, with no responder treating more than 10 cases per year. Most (55.6%) do not use a pediatric-specific treatment algorithm, whereas 30% apply adult guidelines. A conservative approach focusing on rewarming (55.6%), limb elevation (50%), and tetanus status verification (66.7%) was predominant. Imaging and surgical interventions seem to be reserved for severe cases.

CONCLUSIONS

The current literature for pediatric frostbite management lacks specificity. Canadian practices vary, with a trend toward a conservative approach. The limited evidence and rarity of experience highlight the need for further research, ideally in a collaborative multicentric manner, to create a consensus for pediatric frostbite care.

Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Frostbite: 2024 Update

The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for the prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks or burdens for each modality according to methodology stipulated by the American College of Chest Physicians. This is an updated version of the guidelines published in 2019.

Applications of Vascular Imaging and Interventional Radiology Modalities in the Upper Extremity: A Review

Hand and upper extremity (HUE) vascular disorders are encountered frequently by hand surgeons in clinical practice. A wide array of imaging and vascular interventional radiology modalities exists for the diagnosis and treatment of HUE vascular disorders, some of which may not be familiar to the HUE surgeons. In this review article, we summarize the vascular imaging and vascular interventional radiology modalities and their relative advantages, disadvantages, and indications with respect to HUE pathology. We aim to familiarize HUE surgeons with the available types of diagnostic and therapeutic options for HUE vascular pathologies and aid interdisciplinary communication with vascular interventional radiology specialists during the clinical decision-making process.

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 .

The Effects Of Rapid Rewarming On Tissue Salvage In Severe Frostbite Injury

Frostbite is a high morbidity injury caused by soft tissue freezing, which can lead to digit necrosis requiring amputation. Rapid rewarming is a first line treatment method that involves placing affected digits into a warm water bath. This study aims to assess the clinical practices for frostbite at facilities outside of dedicated burn centers, and any impact these practices have on tissue salvage. Retrospective chart review at a single burn center identified frostbite patients admitted directly or as transfers over a seven-year period. Records were reviewed to identify initial treatment strategies. If given, time to thrombolytics from admit was noted. Tissue salvage rates were calculated from radiologically derived tissue at-risk scores and final amputation scores. One-hundred patients were transferred from outside facilities, and 108 were direct admissions (N=208). There was no significant difference in group demographics. Rapid rewarming was the initial treatment modality more commonly in direct admit patients (P=0.016). The use of rapid rewarming did not correlate with tissue salvage (P=0.112). Early use of thrombolytics had a positive impact on tissue salvage (P=0.003). Thrombolytics were given 1.2 hours earlier in direct admit patients (P=0.029), however there was no difference in tissue salvage rates between the groups (P=0.127). Efforts should focus on larger scale study to further assess the effectiveness of rapid rewarming. Although rapid rewarming did not significantly impact tissue salvage in this study, we continue to recommend its use over less studied treatment methods, and continue to view it as an important bridge to burn center transfer and administration of thrombolytic therapy.

Research progress in the pathogenic mechanisms and imaging of severe frostbite

PURPOSE

This article reviews the pathological mechanisms and progress of imaging of severe frostbite to assist in the search for targets for clinical diagnosis and treatment of severe frostbite. This review also aims to provide strong evidence for clinical diagnosis and treatment of deep frostbite.

METHODS

The review was based on the summary and analysis of the existing literature, and explored the pathological mechanism of deep frostbite and the advantages and disadvantages of imaging diagnostic methods.

RESULTS

According to the depth of tissue involvement, frostbite is divided into 4 levels. Severe frostbite includes Grade 3 and Grade 4 frostbite. Clinical performance evaluation and imaging diagnostic research have always been the mainstream of severe frostbite diagnosis. Imaging methods focus on vascular patency and tissue vitality. This article introduces angiography, SETCT/CT and MRA, and we summarize the advantages and disadvantages of these imaging methods. We recommend corresponding imaging modalities according to the state of frostbite patients.

CONCLUSIONS

Imaging examination, especially angiography and bone scans, provide useful information for determining the diagnosis and prognosis of severe frostbite. In order to obtain a good clinical prognosis, clinicians should first perform SPECT/CT. MRA does not burden the patient's body, but the balance between cost and benefit must be considered. Angiography provides a good feedback on the changes in blood vessel status before and after treatment, which is helpful for discovering the response of limbs to treatment.

Expert consensus on the prevention, diagnosis and treatment of cold injury in China, 2020

Cold injury refers to local or systemic injury caused by a rapid, massive loss of body heat in a cold environment. The incidence of cold injury is high. However, the current situation regarding the diagnosis and treatment of cold injury in our country is not ideal. To standardize and improve the level of clinical diagnosis and treatment of cold injury in China, it is necessary to make a consensus that is practical and adapted to the conditions in China. We used the latest population-level epidemiological and clinical research data, combined with relevant literature from China and foreign countries. The consensus was developed by a joint committee of multidisciplinary experts. This expert consensus addresses the epidemiology, diagnosis, on-site emergency procedures, in-hospital treatment, and prevention of cold injury.

Self-inflicted finger cold injury leading to amputation: Report of a case

A cold injury can result in devastating outcomes, leading to significant morbidity and loss of distal extremities. Amputations are common after severe frostbite injuries with delayed presentation, often mediated by post-injury arterial thrombosis. Ischemic injuries are managed according to the ischemia time. The most controversial aspect of treating a salvage injury is the time of surgical intervention, which used to be based on the previous management dogma freeze in January, amputate in July. Recently, the paradigm has shifted to early surgical management if the level of viability of the deep structure can be ascertained using 99mTc pertechnetate scintigraphy (99mTc bone scans). We present a case of a finger amputation resulting from a cold injury secondary to a crush injury.

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.

Guidelines for Thrombolytic Therapy for Frostbite

The data are insufficient to support standardized treatment of all patients with frostbite with thrombolytic therapy. The following guidelines, however, should be applied to all patients with cyanosis persisting proximal to the distal phalanx (Grade 3 or 4 frostbite injury) and demonstrated loss of perfusion at or proximal to the middle phalanx immediately after rewarming.

Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Frostbite: 2019 Update

The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks or burdens for each modality according to methodology stipulated by the American College of Chest Physicians. This is an updated version of the guidelines published in 2014.

Microangiography: An Alternative Tool for Assessing Severe Frostbite Injury

Assessment of frostbite injury typically relies on computed tomography, angiography, or nuclear medicine studies to detect perfusion deficits prior to thrombolytic therapy. The aim of this study was to evaluate the potential of a novel imaging method, microangiography, in the assessment of severe frostbite injury. Patients with severe frostbite were included if they received a post-thrombolytic Technetium 99 (Tc99) bone scan, a Tc99 bone scan without thrombolytic therapy, and/or post-thrombolytic microangiography (MA) study. We included all patients from the years 2006 to 2018 with severe frostbite injury who had received appropriate imaging for diagnosis: Tc99 scan alone (N = 82), microangiography alone (N = 22), and both Tc99 and microangiography (N = 26). The majority of patients received thrombolytic therapy (76.2%), and the average time to thrombolytics was 6.9 hours. Tc99 scans showed strong correlation with amputation level (r = .836, P < .001), and microangiography showed a slightly stronger positive correlation with amputation level (r = .870, P < .001). In the subset who received both Tc99 scan and microangiography (N = 26), we observed significant differences in the mean scores of perfusion deficit (z = 3.20, P < .001). In this subset, a moderate correlation was found between level of perfusion deficit on Tc99 bone scan and amputation level (r = .525, P = .006). A very strong positive correlation was found between the microangiography studies and the amputation level (r = .890, P < .001). These results demonstrate that microangiography is a reliable alternative method of assessing severe frostbite injury and predicting amputation level.

Thrombolytic Salvage of Threatened Frostbitten Extremities and Digits: A Systematic Review

Frostbite is a cold injury that results in soft tissue loss and can lead to amputation. Vascular thrombosis following injury causes ischemic tissue damage. Despite understanding the pathology, its treatment has remained largely unchanged for over 30 years. Threatened extremities may be salvaged with thrombolytics to restore perfusion. The authors performed a systematic review to determine whether thrombolytic therapy is effective and to identify patients who may benefit from this treatment. The Pubmed, EBSCO, and Google Scholar databases were queried using the key words “thrombolytics,” “frostbite,” “fibrinolytics,” and “tPA.” Studies written after 1990 in English met inclusion criteria. Exclusion criteria were failure to delineate anatomic parts injured, failure to report number of limbs salvaged, animal studies, and non-English language publications. Thrombolytic therapy was defined as administration of tPA, alteplase, urokinase, or streptokinase. Forty-two studies were identified and 17 included. Included were 1 randomized trial, 10 retrospective studies, 2 case series, and 4 case reports. One thousand eight hundred and forty-four limbs and digits in 325 patients were studied and 216 patients treated with thrombolytics and 346 amputations performed. The most common means of thrombolysis was intra-arterial tPA. The most common duration of therapy was 48 hours. Limb salvage rates ranged from 0% to 100% with a weighted average of 78.7%. Thrombolytics are a safe and effective treatment of severe frostbite. They represent the first significant advancement in frostbite treatment by preventing otherwise inevitable amputations warranting both greater utilization and further research to clarify the ideal thrombolytic protocol.

Urban Frostbite: Strategies for Limb Salvage

Under ideal circumstances, severely frostbitten extremities are rapidly rewarmed and treated with thrombolytic therapy within 6 to 24 hours. In an “inner city,” urban environment, most patients who suffer frostbite injuries present in a delayed fashion, sustain repeated injuries further complicated by psychological issues or intoxication, and are rarely ideal candidates for thrombolytic therapy within the prescribed timeframe. We describe our experience with the treatment of urban frostbite injuries. A retrospective review of patients with cold injuries sustained between November 2013 and March 2014 treated at a verified burn center in an urban setting was performed. Fifty-three patients were treated (42 males, 11 females). Average patient age was 41.8 years (range 2–84 years). No patients met criteria for thrombolytic therapy due to multiple freeze-thaw cycles or presentation greater than 24 hours after rewarming. Deep frostbite was seen in 10 patients. Of these patients, nine underwent debridement, resulting in partial limb amputations at levels guided by Tri-phasic technetium (Tc-99m) bone scans. Wound closure and limb-length salvage was then achieved by: free flap coverage (n = 2), local flaps (n = 8), split-thickness skin grafting (n = 22), and secondary intention healing (n = 6). While tissue plasminogen activator has been successful in reducing the need for digital amputation following frostbite injuries, in our experience, this treatment modality is not applicable to the urban patient population who often present late and after cycles of reinjury. Therefore, our approach focused on salvaging limb length with durable coverage, as the injuries were unable to be reversed.

Pedicled Abdominal Flaps for Enhanced Digital Salvage After Severe Frostbite Injury

Extremities are the area of the body most commonly affected by frostbite, which can also affect the face, ears, perineum, or genitals. Optimum management has moved away from early amputation and debridement toward maximizing tissue preservation and delaying surgical intervention. Increasing length of digit amputation increases morbidity, in terms of loss of hand function, experienced by patients. Reconstruction of affected digits is limited by bone necrosis, which often leads to shortened residual stumps and limited functional outcomes. This case describes the management of a severe frostbite injury affecting both hands and feet in a 39-y-old man, sustained during descent of Mount Everest. The use of a pedicled abdominal flap to provide soft-tissue cover permitted optimized digit length and function and sensate digits. The case highlights the benefits of early multidisciplinary team involvement in the management of severe frostbite to optimize functional outcome.

The utility of bone scintigraphy with SPECT/CT in the evaluation and management of frostbite injuries

OBJECTIVE:

Frostbite is a localized cold-thermal injury resulting from prolonged exposure of flesh to freezing and near freezing temperatures. The depth and extent of frostbite injuries are not easily assessed, from a clinical standpoint, at the time of injury making it challenging to plan appropriate management and treatment.

METHODS:

A review of the literature of management of cold-related injuries and retrospective case review of the imaging and clinical course of frostbite injury.

RESULTS:

Bone scintigraphy with single photon emission computed tomography (SPECT)/CT was performed in the acute and subacute course of frostbite injuries, subsequently leading to earlier definitive management and shorter hospital stay.

CONCLUSION:

Multiphase technetium-99m-methylenediphosphonate (⁹⁹mTc-MDP) bone scintigraphy with SPECT/CT can expedite clinical management of frostbite injuries by determining the extent of injury and can accurately predict the level of amputation if needed.

ADVANCES IN KNOWLEDGE:

 SPECT/CT is underutilized at many facilities but can have a profound and immediate impact on clinical management of patients with frostbite when used in combination with physiological bone scan imaging.

Use of Intra-arterial Thrombolytic Therapy for Acute Treatment of Frostbite in 62 Patients with Review of Thrombolytic Therapy in Frostbite

Amputations are common after severe frostbite injuries, often mediated by postinjury arterial thrombosis. Since 1994, the authors have performed angiography to identify perfusion deficits in severely frostbitten digits and treated these lesions with intraarterial infusion of thrombolytic agents, usually combined with papaverine to reduce vasospasm. A retrospective review was performed of patients admitted to the regional burn center with frostbite injury from 1994 to 2007. Patients with severe frostbite, without contraindications to thrombolytic therapy, underwent diagnostic angiography of the affected extremities. Limbs with perfusion defects received intraarterial thrombolytic therapy according to protocol and the response was documented. Delayed amputation was performed for mummified digits. Angiogram results and amputation rates were tabulated. In this 14-year review, 114 patients were admitted for frostbite injuries. There was a male predominance (84%) and the mean age was 40.4 years. Of this group, 69 patients with severe frostbite underwent angiography; 66 were treated with intraarterial thrombolytic therapy. Four treated were excluded due to incomplete data. In the remaining 62 patients, angiography identified 472 digits with frostbite injury and impaired arterial perfusion. At the termination of thrombolytic infusion, a completion angiogram was performed. Partial or complete amputations were performed on only four of 198 digits (2.0%) with distal vascular blush, and in 71 of 75 digits (94.7%) with no improvement. Amputations occurred in 73 of 199 digits (36.7%) with partially restored flow. Overall complete digit salvage rate was 68.6%. Angiography after severe frostbite is a sensitive method to detect impaired arterial blood flow and permits catheter-directed treatment with thrombolytic agents. Improved perfusion after such treatment decreases late amputations following frostbite injury.

The evolution of the Helsinki frostbite management protocol

BACKGROUND

Severe frostbite can result in devastating injuries leading to significant morbidity and loss of function from distal extremity amputation. The modern day management approach to frostbite injuries is evolving from a historically very conservative approach to the increasingly reported use of early interventional angiography and fibrinolysis with tPA. The aim of this study was to evaluate the results of our frostbite treatment protocol introduced 3 years ago.

METHODS

All frostbite patients underwent first clinical and then Doppler ultrasound examination. Angiography was conducted if certain clinical criteria indicated a severe frostbite injury and if there were no contraindications to fibrinolysis. Intra-arterial tissue plasminogen activator (tPA) was then administered at 0.5-1mg/h proximal to the antecubital fossa (brachial artery) or popliteal fossa (femoral artery) if angiography confirmed thrombosis, as well as unfractionated intravenous heparin at 500 units/h. The vasodilator iloprost was administered intravenously (0.5-2.0ng/kg/min) in selected cases.

RESULTS

20 patients with frostbite were diagnosed between 2013-2016. Fourteen patients had a severe injury and angiography was performed in 10 cases. The total number of digits at risk was 111. Nine patients underwent fibrinolytic treatment with tPA (including one patient who received iloprost after initial non response to tPA), 3 patients were treated with iloprost alone and 2 patients received neither treatment modality (due to contraindications). The overall digital salvage rate was 74.8% and the Hennepin tissue salvage rate was 81.1%. One patient developed a catheter-site pseudoaneurysm that resolved after conservative treatment.

CONCLUSIONS

Prompt referral to a facility where interventional radiology and 24/7 laboratory services are available, and the combined use of tPA and iloprost, may improve outcome after 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.

Cold burn injuries in the UK: the 11-year experience of a tertiary burns centre

Background

Guidance for the management of thermal injuries has evolved with improved understanding of burn pathophysiology. Guidance for the management of cold burn injuries is not widely available. The management of these burns differs from the standard management of thermal injuries. This study aimed to review the etiology and management of all cold burns presenting to a large regional burn centre in the UK and to provide a simplified management pathway for cold burns.

Methods

An 11-year retrospective  analysis (1 January 2003–31 December 2014)  of all cold injuries presenting to a regional burns centre in the UK was conducted. Patient case notes were reviewed for injury mechanism, first aid administered, treatment outcomes and time to healing. An anonymized nationwide survey on aspects of management of cold burns was disseminated between 13 July 2015–5 October 2015 to British Association of Plastic Reconstructive and Aesthetic Surgeons (BAPRAS) and Plastic Surgery Trainees Association (PLASTA) members in the UK. Electronic searches of MEDLINE, EMBASE and the Cochrane Library were performed to identify relevant literature to provide evidence for a management pathway for cold burn injuries.

Results

Twenty-three patients were identified. Age range was 8 months–69 years. Total body surface area (TBSA) burn ranged from 0.25 to 5 %. Twenty cases involved peripheral limbs. Seventeen (73.9 %)cases were accidental, with the remaining six (26.1 %) cases being deliberate self-inflicted injuries. Only eight patients received first aid. All except one patient were managed conservatively. One case required skin graft application due to delayed healing. We received 52 responses from a total of 200 questionaires. Ninety percent of responders think clearer guidelines should exist. We present a simplified management pathway based on evidence identified in our literature search. 

Conclusions

Cold burns are uncommon in comparison to other types of burn injuries. In the UK, a disproportionate number of cold burn injuries are deliberately self-inflicted, especially in the younger patient population. Our findings reflect a gap in clinical knowledge and experience. We proposed a simplified management pathway for managing cold burn injuries, consisting of adequate first aid using warm water, oral prostaglandin inhibitors, deroofing of blisters and topical antithromboxane therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s41038-016-0060-x) contains supplementary material, which is available to authorized users.

Frostbite: Spectrum of Imaging Findings and Guidelines for Management

Frostbite is a localized cold thermal injury that results from tissue freezing. Frostbite injuries can have a substantial effect on long-term limb function and mobility if not promptly evaluated and treated. Imaging plays a critical role in initial evaluation of frostbite injuries and in monitoring response to treatment. A multimodality approach involving radiography, digital subtraction angiography (DSA), and/or multiphase bone scintigraphy with hybrid single photon emission computed tomography (SPECT)/computed tomography (CT) is often necessary for optimal guidance of frostbite care. Radiographs serve as an initial survey of the affected limb and may demonstrate characteristic findings, depending on the time course and severity of injury. DSA is used to evaluate perfusion of affected soft tissues and identify potential targets for therapeutic intervention. Angiography-directed thrombolysis plays an essential role in tissue preservation and salvage in deep frostbite injuries. Multiphase bone scintigraphy with technetium 99m-labeled diphosphonate provides valuable information regarding the status of tissue viability after initial treatment. The addition of SPECT/CT to multiphase bone scintigraphy enables precise anatomic localization of the level and depth of tissue necrosis before its appearance at physical examination and can help uncover subtle findings that may remain occult at scintigraphy alone. Multiphase bone scintigraphy with SPECT/CT is the modality of choice for prognostication and planning of definitive surgical care of affected limbs. Appropriate use of imaging to direct frostbite care can help limit the effects that these injuries have on limb function and mobility. ©RSNA, 2016.

A retrospective cohort study examining treatments and operative interventions for frostbite in a tertiary care hospital

BACKGROUND

Frostbite is a common yet challenging injury to both diagnose and treat. McCauley's frostbite treatment protocol consists of 12 treatments that might well represent the standard of care. However, its effectiveness in preventing operative intervention has yet to be examined. Our objectives were to characterize frostbite injuries in Eastern Ontario, identify risk factors for deep injuries, and assess the protocol's efficacy in preventing operative outcomes.

METHODS

This cohort study examined patients with frostbite over ten years at a tertiary care hospital. Demographics and predisposing factors were recorded. Frostbite severity was categorized into superficial or deep. Treatments were recorded, including adherence to protocol and operative outcome.

RESULTS

Of the 265 frostbite patients identified, deep frostbite accounted for 56 (21.1%, 95% CI: 16.2-26.1%), of whom 20 (35.7%) had an operative outcome. Amputation occurred in 16 (28.6%) of deep injuries and debridement in 5 (8.9%). Risk factors for deep frostbite were older age (p =0.002), smoking (p <0.001), male sex (p =0.056) and alcohol abuse (p =0.056). None of the patients with deep frostbite had all 12 treatments performed. Adherence to protocol ranged from 0.0% to 48.2% per treatment. The rate of operative intervention was 7.7% in patients with deep frostbite who did not have any McCauley's frostbite treatments and ranged from 0.0% to 100.0% per treatment in those who did receive treatments.

CONCLUSIONS

The frostbite protocol was not regularly followed and therefore its efficacy in preventing operative intervention could not be determined. Further, none of the individual treatments in the protocol were associated with preventing operative intervention. We recommend that future research focus on identifying effective individual treatments.

Freezing and non-freezing cold weather injuries: a systematic review

INTRODUCTION

The debilitating impact of cold weather on the human body is one of the world's oldest recorded injuries. The severe and life-changing damage which can be caused is now more commonly seen recreationally in extreme outdoor sports rather than in occupational settings such as the military. The diagnosis and treatment of these injuries need to be completed carefully but quickly to reduce the risk of loss of limb and possibly life. Therefore, we have conducted a systematic review of the literature surrounding cold weather injuries (CWIs) to ascertain the epidemiology and current management strategies.

SOURCES OF DATA

Medline (PubMED), EMBASE, CINHAL, Cochrane Collaboration Database, Web of Science, Scopus and Google Scholar.

AREAS OF AGREEMENT IMMEDIATE FIELD TREATMENT

The risk of freeze thaw freeze injuries. Delayed surgical intervention when possible. Different epidemiology of freezing and non-freezing injuries.

AREAS OF CONTROVERSY

Prophylatic use of antibiotics; the use of vasodilators surgical and medical.

GROWING POINTS

The use of ilioprost and PFG2a for the treatment of deep frostbite.

AREAS TIMELY FOR DEVELOPING RESEARCH

The treatment of non-freezing CWIs with their long-term follow-up.

Wilderness Medical Society practice guidelines for the prevention and treatment of frostbite: 2014 update

The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for the prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks or burdens for each modality according to methodology stipulated by the American College of Chest Physicians. This is an updated version of the original guidelines published in Wilderness & Environmental Medicine 2011;22(2):156-166.

Frostbite of the hand

Frostbite is damage caused by the freezing of tissue owing to exposure to extreme cold. Clinically, it is often difficult to identify the severity of frostbite injury. There may be a wide discrepancy between the extent of damage to the skin versus that to the deeper structures. The initial clinical impression is usually worse than actual tissue damage. In addition to physical examination, diagnostic imaging, especially triple-phase bone scan, has been proposed to help differentiate between superficial and deep damage. Principles of treatment involve rapid rewarming to thaw the tissues and halt direct cellular damage, methods to minimize progressive dermal ischemia, and active wound care to promote timely healing. Pharmacological adjuncts, such as fibrinolytics, have been proposed to minimize tissue damage. Surgical therapy is postponed until there is clear demarcation between healthy and necrotic tissue.

Frostbite: a practical approach to hospital management

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.

Proposed treatment protocol for frostbite: a retrospective analysis of 17 cases based on a 3-year single-institution experience

BACKGROUND

This paper discusses the treatment protocol for patients with frostbite.

METHODS

We performed a retrospective analysis of a series of 17 patients with second- and higher-degree frostbite who had been treated at our medical institution between 2010 and 2012.

RESULTS

Our clinical series of patients (n=17) included 13 men and four women, whose mean age was 42.4±11.6 years (range, 22-67 years). The sites of injury include the foot in six patients (35.3%), the hand in six patients (35.3%) and the facial region in five patients (29.4%). Seven patients with second-degree frostbite were completely cured with only conservative treatment during a mean period of 12.7±3.3 days (range, 8-16 days). Of the five patients with third-degree frostbite, two underwent skin grafting following debridement, and the remaining three achieved a complete cure with conservative treatment during a mean period of 35±4.3 days (range, 29-39 days). Five patients with fourth-degree frostbite were treated with surgical procedures including amputation.

CONCLUSIONS

With the appropriate conservative management in the early stage of onset, surgeons should decide on surgery after waiting for a sufficient period of time until the demarcation of the wound. Continuous management of patients is also needed to achieve functional recovery after a complete cure has been achieved. This should also be accompanied by patient education for the avoidance of re-exposure to cold environments.

A clinical review of the management of frostbite

Frostbite is a thermal injury that can occur when temperatures drop low enough for tissue to freeze. On rewarming the tissues, an inflammatory process develops which is often associated with tissue loss. The extent of the tissue loss reflects the severity of the cold exposure and includes factors such as temperature, duration, wind chill, altitude, and systemic hypothermia. This review discusses the epidemiology, the pathophysiological processes involved, and the clinical management of frostbite injuries. Practical advice is given on both the field and hospital management and how to seek expert advice from remote situations. The review also discusses newer developments in frostbite treatment such as intra-vascular thrombolysis and adjunctive treatments such as the use of intravenous vasodilators.

Evolving techniques in foot and ankle amputation

Multiple clinical pathways lead to lower extremity amputation, including trauma, dysvascular disease, congenital defects, and malignancy. However, the principles of successful amputation-careful preoperative planning, coordination of a multidisciplinary team, and good surgical technique-remain the same. Organized rehabilitation and properly selected prostheses are integral components of amputee care. In the civilian setting, amputation is usually performed as a planned therapy for an unsalvageable extremity, not as an emergency procedure. The partial loss of a lower limb often represents a major change in a person's life, but patients should be encouraged to approach amputation as the beginning of a new phase of life and not as the culmination of previous treatment failures.

Cold injury

The pathophysiology of true frostbite reveals that the direct injury produced during the initial freeze process has a minor contribution to the global tissue damage. However, rapid rewarming to reverse the tissue crystallization has essentially been the lone frostbite intervention for almost half a century. The major pathologic process is the progressive microvascular thrombosis following reperfusion of the ischemic limb, with the cold-damaged endothelial cells playing a central role in the outcome of these frozen tissues. Newer interventions offer the opportunity to combat this process, and this article offers a scientific approach to frostbite injuries of the upper extremities.

Cold exposure injuries to the extremities

Cold exposure injuries comprise nonfreezing injuries that include chilblain (aka pernio) and trench, or immersion, foot, as well as freezing injuries that affect core body tissues resulting in hypothermia of peripheral tissues, causing frostnip or frostbite. Frostbite, the most serious peripheral injury, results in tissue necrosis from direct cellular damage and indirect damage secondary to vasospasm and arterial thromboses. The risk of frostbite is influenced by host factors, particularly alcohol use and smoking, and environmental factors, including ambient temperature, duration of exposure, altitude, and wind speed. Rewarming for frostbite should not begin until definitive medical care can be provided to avoid repeated freeze-thaw cycles, as these cause additional tissue necrosis. Rewarming should be rapid and for an affected limb should be performed by submersion in warm water at 104 degrees to 107.6 degrees F (40 degrees to 42 degrees C) for 15 to 30 minutes. Débridement of necrotic tissues is generally delayed until there is a clear demarcation from viable tissues, a process that usually takes from 1 to 3 months from the time of initial exposure. Immediate escharotomy and/or fasciotomy is necessary when circulation is compromised. In addition to the acute injury, frostbite is associated with late sequelae that include altered vasomotor function, neuropathies, joint articular cartilage changes, and, in children, growth defects caused by epiphyseal plate damage.

Environmental Cold-Induced Injury

More than 650 deaths from hypothermia occur each year in the United States. Even minor deviation from normal temperature leads to important symptoms and disability. The most significant risk factors are advanced age, mental impairment, substance abuse, and injury. This article examines the incidence of hypothermia, its detrimental effect on trauma patients, and methods of rewarming the hypothermic patient. It also looks at the controversial protective role hypothermia might play in shock, organ transplantation, cardiac arrest, and brain injury. Finally, it examines cold injuries, including frostbite, chilblain, and trench foot, and makes recommendations for their treatment.

Alpine climbing: injuries and illness

Alpine climbing is a sport whose participants are at risk for a variety of injuries and illnesses. Climbers are venturing into the mountains and attempting routes with ever-increasing difficulty, and it is important to understand the injury and illness concerns of alpine climbers better. Alpine climbers are prone to injuries common to traditional mountaineers and more specialized sport rock climbers. Falls while climbing represent one of the more common causes of serious injury, although acute and chronic musculoskeletal injuries of the hands and extremities are also frequent afflictions. Alpine climbers are at risk for injuries and illness because of the mountain environment where they participate in their sport. Proper preparation for the cold is imperative to prevent frostbite and hypothermia. Worsening symptoms of headache or respiratory symptoms should always alert the alpine climber to possible altitude illness. Understanding the injuries common to the sport can allow providers to deliver the best medical care.

Predictive value of 99mTc-sestamibi scintigraphy for healing of extremity amputation

PURPOSE

Although various non-invasive procedures have been proposed to determine the optimal level of amputation of limbs in patients who have vascular disease, currently there are no consistent criteria that can be applied before surgery. The purpose of this study was to determine whether (99m)Tc-sestamibi imaging can accurately predict the healing of amputation sites.

METHODS

In a prospective study in 26 patients (21 men, 5 women; age range 23-94 years) presenting with ulcers or gangrene of the foot and hand, (99m)Tc-sestamibi imaging was performed preoperatively. The indications for amputation included gangrene (23 patients), electrical injury (2 patients) and trauma (1 patient) of extremities. Although the amputation levels were chosen according to clinical criteria and scintigraphic results, the final amputation level was defined by scintigraphic results. Two below-knee, one above-knee, 12 toe, 11 transmetatarsal, two phalanx, one finger and one thumb amputations and one shoulder disarticulation were performed. In four cases, the amputation defect was not suitable for coverage using a local dermal flap; rather, it was covered with free tissue transfer. Patients had clinical follow-up for 6-36 months (mean 11.69 months) to assess healing of the stump. Scan results were compared with clinical outcome to assess prediction of healing.

RESULTS

There was healing in all amputations at the end of the follow-up period. When evaluated regarding preoperative (99m)Tc-sestamibi uptake pattern, there was no perfusion to the lesion site in 21 patients and perfusion to an area smaller than the extent of skin necrosis in four patients; thus, in these 25 patients, (99m)Tc-sestamibi scintigraphy suggested non-viable tissue in the extremities with clear-cut edges of perfused muscle tissue. Diffusely decreased uptake was seen below the left knee in one case. How scintigraphy changed management was analysed. The amputation levels proposed before scintigraphy were divided into two groups, "definite" (n=14) and "indefinite" (n=12), based on visual examination and Doppler findings. In nine patients in the definite group, the proposed amputation level before scintigraphy was not altered by the scintigraphic data. However, (99m)Tc-sestamibi scan enabled unnecessarily high amputation levels to be avoided in 12 patients in the indefinite group and in five patients in the definite group. Therefore, there was change in management of 65% of cases based on scintigraphic findings.

CONCLUSION

Since healing of the stump was seen in all cases, outcome was correctly predicted by scintigraphy. This preliminary study supports the use of (99m)Tc-sestamibi scan in selecting the optimal amputation level consistent with subsequent stump healing.

Imaging of frostbite injury by technetium-99m-sestamibi scintigraphy: a case report

The appearance of superficial tissue is often an unreliable indicator of deep-tissue viability in cases of frostbite. We present a 34-year-old black man who was brought to the emergency department at fourth post-injury day with frostbite injury involving both lower extremities after prolonged exposure to subzero temperatures. In our previous experimental study, 99mTc sestamibi scintigraphy has been employed for evaluating frostbite injuries in rabbit hindlegs. In the case presented, 99mTc sestamibi scintigraphy, as a new diagnostic tool, was performed for detection of skeletal muscle perfusion on the fourth post-injury day. The scintigraphic images show diffusely reduced uptake in soft tissues of both calves and feet. It was thought that this hypoperfusion was due to viable but ischemic tissue. Five days after medical therapy, 99mTc sestamibi scan showed prominently increased uptake in both calves and feet and skin necrosis was observed. Debridement of necrotic skin and subcutaneous tissue was performed, and split-thickness skin graft was applied for coverage of the skin defect. Healing was good 15 days after grafting. We think 99mTc sestamibi scan can be used for assessment of soft-tissue perfusion and evaluation of treatment in frostbite injury.

[Aseptic bone necrosis following reimplantation of a degloving finger]

We report a case of microsurgical replantation of a degloved finger in a manual worker. Four months following replantation, avascular necrosis of the middle and distal phalanges was apparent. Amputation at the level of the proximal phalanx was performed. Re-plantation is the solution of choice for such degloving injuries, but a different flap can be used if replantation is not possible. Avascular necrosis of bone is an unfrequent complication, but surgeons should be aware of it.