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.

Editor's Choice - Acute Kidney Injury (AKI) in Aortic Intervention: Findings From the Midlands Aortic Renal Injury (MARI) Cohort Study.

Objectives: The incidence of acute kidney injury (AKI) after open (OAR) or endovascular (EVAR) aortic repair is unknown. This research assessed the proportion of patients who develop AKI after aortic intervention using validated criteria, and explored AKI risk factors.

Methods: This was a multicentre national prospective cohort study.

Purine nucleoside use as surrogate markers of cerebral ischaemia during local and general anaesthetic carotid endarterectomy.

Objectives: In periods of cerebral ischaemia, adenosine triphosphate is metabolised, leading to accumulation of adenosine inosine and hypoxanthine. These can be measured in real time using peripheral blood samples intraoperatively. The primary aim of this study was to describe changes in purine concentrations in a cohort of patients undergoing carotid endarterectomy under general anaesthetic, and to evaluate correlation between changes in values with major perioperative steps.

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.

The clinical application of purine nucleosides as biomarkers of tissue Ischemia and hypoxia in humans .

During periods of ischemia and hypoxia, intracellular adenosine triphosphate stores are rapidly depleted. Its metabolism results in release of purine nucleosides into the systemic circulation. While the potential of purine nucleosides as a biomarker of ischemia has long been recognized, this has been limited by their complex physiological role and inherent instability leading to problematic sampling and prolonged, complex analysis procedures.

HYDration and Bicarbonate to Prevent Acute Renal Injury After Endovascular Aneurysm Repair With Suprarenal Fixation: Pilot/Feasibility Randomised Controlled Study (HYDRA Pilot Trial).

Objective/background: Up to 25% of patients undergoing elective endovascular aneurysm repair (EVAR) develop acute kidney injury (AKI), which is associated with short and long-term morbidity and mortality. There is no high quality randomised evidence regarding prevention of EVAR related AKI.

Methods: A novel AKI prevention strategy for EVAR was devised, based on best evidence and an expert consensus group.

Magnetic Resonance investigation into the mechanisms involved in the development of high-altitude cerebral edema.

Rapid ascent to high altitude commonly results in acute mountain sickness, and on occasion potentially fatal high-altitude cerebral edema. The exact pathophysiological mechanisms behind these syndromes remain to be determined. We report a study in which 12 subjects were exposed to a FiO = 0.

Extreme, expedition, and wilderness medicine.

Extreme, expedition, and wilderness medicine are modern and rapidly evolving specialties that address the spirit of adventure and exploration. The relevance of and interest in these specialties are changing rapidly to match the underlying activities, which include global exploration, adventure travel, and military deployments. Extreme, expedition, and wilderness medicine share themes of providing best available medical care in the outdoors, especially in austere or remote settings.

Acute Mountain Sickness (AMS) Knowledge Among High Altitude Marathon Runners Competing in the Everest Marathon.

Objective: Although there are a number of studies on trekkers' knowledge of acute mountain sickness (AMS), there is little current literature on other groups at altitude, for example, marathon runners. Increased knowledge of AMS is associated with a lower incidence of AMS. The purpose of this study was to determine AMS knowledge of marathon runners with an aim to improve AMS information distribution.

The cerebral venous system and hypoxia.

Most hypobaric hypoxia studies have focused on oxygen delivery and therefore cerebral blood inflow. Few have studied venous outflow. However, the volume of blood entering and leaving the skull (∼700 ml/min) is considerably greater than cerebrospinal fluid production (0.

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.

The feasibility and applications of non-invasive cardiac output monitoring, thromboelastography and transit-time flow measurement in living-related renal transplantation surgery: results of a prospective pilot observational study.

Introduction: Delayed graft function (DGF) remains a significant and detrimental postoperative phenomenon following living-related renal allograft transplantation, with a published incidence of up to 15%. Early therapeutic vasodilatory interventions have been shown to improve DGF, and modifications to immunosuppressive regimens may subsequently lessen its impact. This pilot study assesses the potential applicability of perioperative non-invasive cardiac output monitoring (NICOM), transit-time flow monitoring (TTFM) of the transplant renal artery and pre-/perioperative thromboelastography (TEG) in the early prediction of DGF and perioperative complications.

Intracranial pressure at altitude.

Rapid ascent to high altitude can result in high altitude headache, acute mountain sickness, and less commonly, high altitude cerebral or pulmonary edema. The exact mechanisms by which these clinical syndromes develop remain to be fully elucidated. Direct and indirect measures of intracranial pressure (ICP) usually demonstrate a rise in pressure when human subjects and animals are exposed to acute hypoxia.

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.

Risk stratification by pre-operative cardiopulmonary exercise testing improves outcomes following elective abdominal aortic aneurysm surgery: a cohort study.

Background: In 2009, the NHS evidence adoption center and National Institute for Health and Care Excellence (NICE) published a review of the use of endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs). They recommended the development of a risk-assessment tool to help identify AAA patients with greater or lesser risk of operative mortality and to contribute to mortality prediction.A low anaerobic threshold (AT), which is a reliable, objective measure of pre-operative cardiorespiratory fitness, as determined by pre-operative cardiopulmonary exercise testing (CPET) is associated with poor surgical outcomes for major abdominal surgery.

The Young Everest Study: preliminary report of changes in sleep and cerebral blood flow velocity during slow ascent to altitude in unacclimatised children.

Background: Cerebral blood flow velocity (CBFV) and sleep physiology in healthy children exposed to hypoxia and hypocarbia are under-researched.

Aim: To investigate associations between sleep variables, daytime end-tidal carbon dioxide (EtCO2) and CBFV in children during high-altitude ascent.

Methods: Vital signs, overnight cardiorespiratory sleep studies and transcranial Doppler were undertaken in nine children (aged 6-13 years) at low altitude (130 m), and then at moderate (1300 m) and high (3500 m) altitude during a 5-day ascent.

Registry report on kinetics of rescue antiplatelet treatment to abolish cerebral microemboli after carotid endarterectomy.

Background And Purpose: Cerebral microemboli signals (MES) are associated with increased risk of acute stroke syndromes. We compared the effects on cerebral microemboli after carotid endarterectomy of tirofiban with dextran-40.

Methods: We used transcranial Doppler ultrasound to study transient MES acutely after carotid endarterectomy between August 2000 and December 2010 in 128 subjects refractory to preoperative antiplatelet treatment.

The role of feedback in improving the effectiveness of workplace based assessments: a systematic review.

Background: With recent emphasis placed on workplace based assessment (WBA) as a method of formative performance assessment, there is limited evidence in the current literature regarding the role of feedback in improving the effectiveness of WBA. The aim of this systematic review was to elucidate the impact of feedback on the effectiveness of WBA in postgraduate medical training.

Methods: Searches were conducted using the following bibliographic databases to identify original published studies related to WBA and the role of feedback: Medline (1950-December 2010), Embase (1980-December 2010) and Journals@Ovid (English language only, 1996-December 2010).

The headache of high altitude and microgravity--similarities with clinical syndromes of cerebral venous hypertension.

Syndromes thought to have cerebral venous hypertension as their core, such as idiopathic intracranial hypertension and jugular foramen outlet obstruction, classically result in headaches. Do they provide an insight into the cause of the headache that commonly occurs at altitude? The classic theory of the pathogenesis of high altitude headache has been that it results from increased intracranial pressure (ICP) secondary to hypoxemia in people who have less compliant intracranial volumes (Roach and Hackett, 2001). However, there does not appear to be a correlation between the headache of acute mountain sickness (AMS) and the presence of cerebral edema (Bailey et al, 2006; Wilson et al, 2009).

Wilderness Medical Society practice guidelines for the prevention and treatment of frostbite.

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.

Cerebral artery dilatation maintains cerebral oxygenation at extreme altitude and in acute hypoxia--an ultrasound and MRI study.

Transcranial Doppler is a widely used noninvasive technique for assessing cerebral artery blood flow. All previous high altitude studies assessing cerebral blood flow (CBF) in the field that have used Doppler to measure arterial blood velocity have assumed vessel diameter to not alter. Here, we report two studies that demonstrate this is not the case.

Perioperative transorbital Doppler flow imaging offers an alternative to transcranial Doppler monitoring in those patients without a temporal bone acoustic window.

Transcranial Doppler has been used to identify microembolic signals before, during and after carotid endarterectomy, but 10% to 15% of patients are reported not to have suitable temporal bone window. The aim of this study was to assess the feasibility of transorbital Doppler monitoring of patients with absent temporal bone acoustic window. Between 2005 and 2008, those patients with absent temporal bone acoustic window were assessed for a transorbital acoustic window.