Nitrous oxide tank cold burn to the forearm: a case study and discussion of the literature.

Nitrous oxide (N 2 O) has become one of the most popular recreational drugs in Europe. While N 2 O is often used in medical settings as an analgesic and anaesthetic agent, its recreational use was documented many years before its introduction into clinical practice. The desired effects from inhaling N 2 O for recreational purposes include rapid feelings of relaxation, calmness and euphoria, which can be accompanied by giddiness and laughter. There are various adverse effects associated with N 2 O use, including headache, nausea, vomiting, drowsiness and the development of permanent neurological damage. Furthermore, its use is associated with cold burns and road accidents. This article details the case of a patient who sustained an N 2 O tank burn to his forearm from recreational use. It also discusses the prevalence, legal status and adverse effects of N 2 O use as well as the pathophysiology and management of cold burn injuries.

Nonfreezing Cold Injury and Cold Intolerance in Paddlesport.

INTRODUCTION: Nonfreezing cold injury (NFCI) occurs when tissues are subjected to prolonged cooling that causes tissue damage, but not freezing. Long-term effects include cold intolerance, with allodynia, pain, or numbness of the affected limb. Those who participate in outdoor paddlesports are at particular risk. METHODS: This is an epidemiological study that aimed to determine the risk factors for paddlesport athletes developing NFCI and chronic cold intolerance in their hands. Secondary outcomes were to correlate cumulative cold exposure with the development of cold intolerance and to identify risk factors for developing NFCI or cold intolerance. Six hundred nine athletes responded to a survey distributed by their national governing body obtaining demographic and activity details, symptoms of NFCI, and a cold intolerance severity score (CISS). RESULTS: Twenty-three percent reported symptoms consistent with acute NFCI. The median CISS was 31 y (interquartile range 25-43), and 15% had a pathological CISS defined as >50. Females and individuals with Raynaud's phenomenon or migraines had a significantly higher CISS (P<0.05). Regression analysis found that females, smokers, and those with Raynaud's phenomenon or a previous nerve injury had a significantly higher risk of developing pathological cold intolerance (CISS >50). There was no correlation between cumulative cold exposure and CISS. CONCLUSIONS: A large proportion of paddlesport athletes undertaking activity in cold conditions have a pathological CISS or episodes consistent with NFCI. Cumulative cold exposure was not associated with a pathologically high CISS. The risk factors were female sex, smokers, and those suffering from either Raynaud's phenomenon or nerve injury.

Cryogenic Refrigerant Burns: A Rare Occupational Hazard.

BACKGROUND: Cryogenic burns induced by coolant gases used in refrigerators and air conditioners are rarely encountered, despite the wide use of these gases. To date, only a few cases have been reported in the literature. This study examined the occupational circumstances leading to such injuries, relevant injury sites, types of chemicals involved, and treatment measures. METHODS: This study was conducted in a tertiary burn center in India between March 2015 and March 2019. The demographic details, chemicals involved, and burn regions and characteristics were analyzed. FINDINGS: There were 15 burn cases all involving injury to the hand. All injuries were managed initially with dressings and nonoperative management. One patient required anti-edema therapy with limb elevation and fingertip debridement, while another patient required skin grafting. All patients had satisfactory hand function after treatment. CONCLUSIONS/APPLICATION TO PRACTICE: Cryogenic burn injuries caused by refrigerants are rare, and their etiology varies considerably. Exposure time is the primary factor that determines burn depth and severity; hence, reducing exposure time is important in first aid. Our findings suggest that after exposure, the patient should be treated in a specialized burn center. Adequate knowledge regarding the pathophysiology of these types of burn injuries and their management is necessary; otherwise, misjudgments in the treatment plan can lead to adverse consequences.

Update: Cold Weather Injuries, Active and Reserve Components, U.S. Armed Forces, July 2015-June 2020.

From July 2019 through June 2020, a total of 415 members of the active (n=363) and reserve (n=52) components had at least 1 medical encounter with a primary diagnosis of cold injury. The crude overall incidence rate of cold injury for all active component service members in 2019-2020 (27.4 per 100,000 person-years [p-yrs]) was lower than the rate for the 2018-2019 cold season (35.1 per 100,000 p-yrs) and was the lowest rate during the 5-year surveillance period. In 2019-2020, frostbite was the most common type of cold injury among active component service members in all 4 services. Among active component members during the 2015-2020 cold seasons, overall rates of cold injuries were generally highest among males, non-Hispanic black service members, the youngest (less than 20 years old), and those who were enlisted. The number of cold injuries associated with overseas deployments during the 2019-2020 cold season (n=10) was the lowest count during the 5-year surveillance period. Frostbite accounted for three-fifths (n=6; 60.0%) of the cold weather injuries diagnosed and treated in service members deployed outside of the U.S during the 2019-2020 cold season.

20 Armoured Infantry Brigade downgrade study: epidemiology of principal conditions and plugging leaks in the rehabilitation pipeline.

INTRODUCTION: In April 2017, 22% of Army Full-time Trade Trained Strength was downgraded, reducing fully deployable strength to 60 546, against a target of 82 000. In June 2017, Commander 20 Armoured Infantry Brigade (20 AI Bde) initiated a study to look at the principal conditions causing medical downgrading, as a stepping stone to finding ways of reducing injury, enhancing rehabilitation and improving deployability. METHOD: The Defence Medical Information Capability Programme medical records for every downgraded soldier in 20 AI Bde and supporting units were scrutinised to identify their Medical Deployment Standard and the primary condition causing downgrading. RESULTS: A total of 842 downgraded soldiers were identified from a held strength of 3827 personnel. Sixty-five per cent of these downgrades were due to musculoskeletal injury (MSKI). Of this 65%, the majority were due to knee (31%), spine (28%) and foot/ankle (23%). Of the remaining 35%, the majority were due to noise-induced hearing loss (NIHL) (22%), adjustment disorders (19%) and non-freezing cold injury (NFCI) (13%).Several factors that slowed an individual's recovery pathway were identified. They mainly relate to soldiers being lost to follow-up through lack of active case management. CONCLUSIONS: MSKI is responsible for most downgraded personnel at Brigade level. The distribution of principal conditions is similar to previous studies looking at recruits and individual units.The creation of a rehabilitation troop, delivering active case management, can reduce the number of soldiers leaking out of the rehabilitation pipeline.

Relation between finger cold-induced vasodilation and rewarming speed after cold exposure.

PURPOSE: The risk for local cold injuries has been linked to poor cold-induced vasodilation (CIVD) during cold exposure and to poor rewarming after cold exposure. The purpose of this study is to establish the relation between CIVD and rewarming speed. METHODS: Twelve participants immersed one hand in ice water for 30 min to evoke CIVD and the other hand in ice water for 10 min to investigate the rewarming profile. The ring, middle and index fingertip temperatures were monitored during hand immersion and the resistance index of frostbite (RIF) was calculated. RIF depends on minimal (Tmin) and mean (Tmean) finger skin temperature and onset time. Rewarming was quantified using an infrared imaging system and the rewarming speed over 19 min was determined. RESULTS: Tmin (5.8 ± 3.0 °C) and Tmean (10.4 ± 3.0 °C) caused non-distinctive contributions to the total RIF-scores so that onset time (12.7 ± 3.1 min) became the dominant factor. A significant negative correlation between RIF and rewarming speed was found (rs = - 0.60, p = 0.041). CONCLUSIONS: The negative relation between RIF and rewarming speed may be explained by the common observation that onset time relates to the temperature of fingertip tissue, while Tmin, Tmean and rewarming speed relates to body thermal status. The rewarming test is to be preferred over the CIVD test in terms of ease of use, but the predictive value of the rewarming test for cold injuries is limited, cannot replace the RIF since onset time of finger vasodilation is not included and should be further investigated.

Intentional self-inflicted and peer-inflicted aerosol skin injuries called 'frosties': Cohort series and systematic literature review.

BACKGROUND AND OBJECTIVES: 'Frosties' are deliberate cold skin burns caused by an aerosol device. The aim of this article was to examine our own cohort, and those previously published, to identify the key features of patients presenting with frosties and inform appropriate early clinical interventions. METHOD: We compared cases in our dataset that occurred between 1 January 2013 and 30 June 2017 with those reported in the literature, focusing on seven domains: sex, age at injury, days to presentation, first aid, depth of injury and outcome. RESULTS: The median patient age was 13 years; 70.5% were female. Adequate first aid was not reported in any patient. Where recorded, the median time to presentation to a health service was six days. Where severity of injury was recorded, 13 of 37 cases (35.1%) were full thickness, and 10 patients received a split thickness skin graft. Two subgroups were identified: cluster injuries and psychological distress. DISCUSSION: Cluster injuries occur as the result of a mutual 'test of courage'. Solo injuries may point to underlying psychological distress. Frosties frequently result in significant burn injuries and often require skin grafting. The severity of frosties is underappreciated and, as a consequence, treatment, through first aid or presentation to a health service, is delayed or absent. General practitioners should be familiar with the appearance of frosties in order to identify them in unrelated consultations.

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.

Cold Susceptibility of Digit Stumps Resulting from Amputation After Freezing Cold Injury in Elite Alpinists.

Gorjanc, Jurij, Shawnda A. Morrison, Rok Blagus, and Igor B. Mekjavic. Cold susceptibility of digit stumps resulting from amputation after freezing cold injury in elite alpinists. High Alt Med Biol. 19:185-192, 2018. AIM: The aim of the study was to assess whether previous freezing cold injury in fingers and/or toes might predispose alpinists to greater risk of further freezing cold injury, primarily due to a greater vasoconstrictor response to cold, resulting in a lower perfusion, reflected in lower skin temperature. METHODS: Ten elite alpinists (N = 10; 8 male and 2 female) with amputations after freezing cold injury participated in a cold-water (8°C) immersion stress test of the hands and feet. Digit skin temperatures of amputated digits, their noninjured counterparts, noninjured digits of the affected side and noninjured digits of the corresponding side were measured. The skin temperatures were compared during three consecutive phases of the cold stress test: prewarming, cold water immersion, and passive heating. RESULTS: Amputated toes cooled much faster compared to their uninjured counterparts (n = 26, p < 0.001), and attained lower skin temperatures during the cold exposure test (n = 26, p < 0.001). Higher cooling rate was observed in all the toes on the injured limb compared with the toes on the uninjured limb (n = 40, p < 0.001). In contrast to the toes, the fingers on the injured limb after freezing cold injury were warmer during cooling phase compared to uninjured fingers (n = 15, p < 0.001). CONCLUSIONS: The lower digit temperatures observed in affected toe stumps during the cold stress test compared to the nonamputated toes may indicate a heightened risk of future freezing cold injury with subsequent cold exposures, as a consequence of less perfusion, reflected in the lower skin temperature. This relationship was not confirmed in the fingers.

Update: Cold weather injuries, active and reserve components, U.S. Armed Forces, July 2010-June 2015.

From July 2014 through June 2015, the number of active and reserve component service members treated for cold injuries (n=603) was much lower than the 719 cases diagnosed during the previous, unusually cold winter of 2013- 2014. Army personnel accounted for the majority (51%) of cold injuries. Frostbite was the most common type of cold injury in each of the services except the Marine Corps for which immersion foot was unusually common. Consistent with trends from previous cold seasons, service members who were female, younger than 20 years old, or of black, non-Hispanic race/ethnicity tended to have higher cold injury rates than their respective counterparts. Numbers of cases in the combat zone have decreased in the past 3 years, most likely the result of declining numbers of personnel exposed and the changing nature of operations. It is important that awareness, policies, and procedures continue to be emphasized to reduce the toll of cold injuries among U.S. service members.

Finger and Toe Temperature Responses to Cold After Freezing Cold Injury in Elite Alpinists.

OBJECTIVE: To assess whether previous freezing cold injuries (FCI) would affect digit skin temperatures and rewarming rates during a follow-up cold stress test protocol. DESIGN: Nonrandomized control trial. METHODS: Twenty elite alpinists participated; alpinists with previous FCI requiring digit amputations (injured, INJ: n = 10 total, n = 8 male) were compared with ability-matched, uninjured alpinists (control, CON: n = 10, all male). Digit skin temperature was measured using infrared thermography as an index of peripheral digit perfusion after a cold stress test, which consisted of 30 minutes of immersion in 8°C water. RESULTS: The INJ alpinists' injured toes were warmer (approximately 6%) than their uninjured toes immediately after cold immersion (95% CI, 0.01°C to 1.00°C; P = .05); there were no differences between the rates of rewarming of injured and uninjured toes (INJ, 0.5° ± 0.1°C/min; CON, 0.7° ± 0.3°C/min; P = .16). Although the INJ alpinists had colder injured fingers immediately after the 35°C warm bath compared with their own uninjured fingers (32.2° ± 2.0°C vs 34.5° ± 0.5°C; P = .02), there were no differences observed between the rates of rewarming of injured and uninjured fingers after cold exposure (INJ, 1.1° ± 0.2°C/min; CON, 1.3° ± 0.5°C/min; P = .22). CONCLUSIONS: Even after FCI that requires digit amputation, there is no evidence of different tissue rates of rewarming between the injured and uninjured fingers or toes of elite alpinists.