F rostbite can occur in cold climates, affecting a range of patients from those who are homeless or unwell, to athletes in extreme sports events. The impact of severe frostbite can be debilitating. Frostbite injuries are a result of an initial extracellular freezing injury followed by a reperfusion injury due to vasoconstriction and microthrombosis in affected tissues. 1 The severity of injuries can range from mild to severe. A grading system developed by Cauchy and colleagues 2,3 describes grade 1 to grade 4 frostbite. The higher the grade, the more proximal the cyanotic changes in the digits, and the higher the amputation rate.The foundations of frostbite treatment have included rapid rewarming 4 and antithromboxane agents such as aloe vera for topical use and ibuprofen. 5 More recently, vasodilators and thrombolytics have been promoted to address the reperfusion injury caused by vasoconstriction and thrombosis. Beginning in the 1990s, a growing body of evidence has popularized the use of iloprost in frostbite, first in Europe and now in Canada. 6,11,15,16,21,24,27 Iloprost, a synthetic prostacyclin analogue, is a potent vasodilator that inhibits platelet aggregation and enhances fibrinolytic activity by releasing endogenous tissue plasminogen activator. 29 To our knowledge, there is a single randomized controlled trial published to date showing the benefit of iloprost combined to alteplase and heparin. 11 We developed and implemented a frostbite treatment protocol and preprinted orders at our institution based on the best available evidence in February 2015. The aim of the present study was to describe the demographic characteristics, treatment course and clinical outcomes of patients treated as per our protocol.

A 46-year-old man was evacuated by air ambulance to Whitehorse General Hospital from the Yukon Arctic Ultra race, a 692-km running race. He had been running for 27 hours in temperatures ranging from -45°C to -50°C. Wearing only thin gloves, he had repeatedly exposed his hands to cold air and cold objects to drink, eat and adjust his gear. He had been running on snow, wearing cross-country running shoes. Feeling numbness in his hands and feet, he stopped running and passively rewarmed his hands in his sleeping bag while waiting for rescue. He presented to the emergency department with pain and discomfort in his hands and feet.On presentation, the patient's core temperature was 36.8°C. He had evidence of grade 3 frostbite to the right hand, with hemorrhagic blistering into the proximal phalanges of the fourth and fifth digits (Figure 1). His left hand showed evidence of frostbite on the volar aspect of the distal phalanges of the second and fourth digits. He also had frostbite to his left first and second toe, his right foot and his nose. He had no other injuries. He was healthy and athletic, with no contributing medical history. He was a nonsmoker and had not consumed alcohol recently.The patient's hands and feet were placed in a whirlpool bath of water mixed with chlorhexidine at 38°C until they were pink and warm. He was given ibuprofen 600 mg by mouth every six hours and fentanyl and morphine intravenously for pain. Once the patient's hands and feet were rewarmed, the clear blisters were aspirated, after which aloe vera ointment and porous lowadherent wound dressings were applied.The patient was given iloprost intravenously, titrated to the maximum dose of 2 ng/kg per min, for six hours daily for five days. The infusion rate was increased gradually to avoid adverse effects (e.g., headaches or hypotension). He tolerated the infusion well.On follow-up six months later, the patient's hands and feet showed complete healing. Amputation had not been required, but he reported hypersensitivity to touch and temperature. Case 2A 43-year-old man presented to the emergency department of Whitehorse General Hospital after completing the 100-mile (161-km) event of the Yukon Arctic Ultra race. He ran in temperatures ranging from -30°C to -50°C for 64 hours and then rewarmed his feet in a hot tub at his hotel. On presentation, he reported that his toes were numb and white. He was given oral cephalexin and discharged home. He returned to the emergency department 48 hours later concerned about a loss of sensation in his great toes. He recognized that he had frostbite and was seeking an alternative approach to watchful waiting.The patient had grade 3 frostbite to both great toes, with some mild erythematous extension into the metatarsophalangeal area of his right foot (Figure 2).The patient was a healthy and athletic orthopedic surgeon, with no contributing medical history. He was a nonsmoker and consumed alcohol occasionally. He was an experienced adventurer and had travelled to both poles in the past.The oral antibiotic was sto...

Guideline dissemination for the management of acute community-acquired pneumonia significantly increased prescriber compliance in the emergency department and on wards.

Contralateral torques exerted at the hip were measured in healthy subjects and subjects with hemiparesis performing unilateral static hip efforts in abduction, adduction, flexion and extension, in a sitting position, at two torque levels. In general, the ipsilateral hip efforts were accompanied by mirrored contralateral torques in both groups of subjects. The directionality of these contralateral torques indicates that their action at the pelvis is mechanically opposite to the ipsilateral efforts, suggesting that they ensure the stabilization of the pelvis. In healthy subjects, analyses of variance showed no difference in the magnitude of the contralateral torques with regard to which limb was used to perform the task. However, a significant increase in magnitude was demonstrated in the contralateral torques concurrent with the increasing level of effort requested ipsilaterally. In hemiparetic subjects, when performing the tasks with their paretic limb, the magnitude of the contralateral torques was significantly increased in the non-paretic limb when compared with those measured in the paretic limb during non-paretic limb efforts. Based on the present results, a model of postural control is presented to explain the relationship between the ipsilateral and contralateral torques. Using this model, it is hypothesized that the increased contralateral torques observed in hemiparetic subjects when performing the tasks with their paretic limb is related to the weakness of the paretic muscles. The clinical importance of exercises used for the re-education of the paretic lower limb in this population, which consist of resisting the non-paretic hip movements in order to strengthen the paretic hip muscles, is discussed in light of these results.

Some of the factors that influence the reduction of disulfide-containing peptides under fast-atom bombardment have been investigated using two neurohormonal peptides that include disulfide bridges in their structures. Deaminoarginine-vasopressin (DAVP) and arginine-vasopressin (AVP) have been analyzed as their acetate and trifluoroacetate salts. Results obtained in a thioglycerol matrix indicate that the peptides analyzed as their acetate salts are completely reduced under bombardment, whereas the trifluoroacetate salts show little evidence of reduction. Addition of trifluoroacetic acid to the acetate sample prior to bombardment inhibits reduction whereas addition after bombardment shows no effect on the reduction, thereby indicating the irreversibility of the process. Time-monitoring experiments conducted with the acetate salts of DAVP and AVP in common matrices such as thioglycerol, dithiothreitol + diethioerythritol, glycerol, hydroxyethyldisulfide and nitrobenzyl-alcohol demonstrate an important effect of the chemical nature of the matrix on reduction. In matrices containing thiol groups, the reduction is extensive, whereas it is almost suppressed in matrices such as hydroxyethyldisulfide and nitrobenzylalcohol. However, the addition of trifluoroacetic acid to all of these matrices essentially eliminates reduction and provides measured isotopic peak ratios that are in agreement with theoretically calculated values for these peptides.

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We performed a scoping review to identify the extent of the literature describing the use of iloprost in the treatment of frostbite. Iloprost is a stable synthetic analog of prostaglandin I 2 . As a potent inhibitor of platelet aggregation and vasodilator, it has been used to address the post-rewarming reperfusion injury in frostbite. The search using iloprost and frostbite as key words and MeSH terms yielded 200 articles. We included in our review the literature examining iloprost for the treatment of frostbite in humans in the form of primary research, conference proceedings and abstracts. Twenty studies published from 1994 to 2022 were selected for analysis. The majority were retrospective case series consisting of a homogeneous population of mountain sport enthusiasts. A total of 254 patients and over 1000 frostbitten digits were included among the 20 studies. The larger case series demonstrated a decrease in amputation rates relative to untreated patients. Primary gaps in the literature include a paucity of randomised trials and relatively limited study populations to date. While the case evidence is promising, a multi-centre collaboration would be crucial to adequately power prospective randomised studies to definitively determine if iloprost has a role in the treatment of frostbite.

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