Wilderness Medical Society Clinical Practice Guidelines for the Treatment of Acute Pain in Austere Environments: 2024 Update.

The Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the management of pain in austere environments. Recommendations are graded based on the quality of supporting evidence as defined by criteria put forth by the American College of Chest Physicians. This is an update of the 2014 version of the "WMS Practice Guidelines for the Treatment of Acute Pain in Remote Environments" published in Wilderness & Environmental Medicine 2014; 25:41-49.

Cardiovascular Disease and Triathlon-Related Deaths in the United Kingdom.

INTRODUCTION: Triathlon is one of the fastest growing sports in the United Kingdom. However, in recent years several deaths have occurred. The intention of this study is to identify these cases and examine the role cardiovascular disease played in these deaths. METHODS: An extensive online search was performed to identify triathlon-related deaths (TRDs) in the United Kingdom and UK citizens who died during or as a result of competing in triathlons abroad. British Triathlon provided the number of participants who took part in UK-based events. Coroners provided information on all those who died. RESULTS: Between 2009 and 2015, 991,186 participants took part in British Triathlon-sanctioned events. Five TRDs in the United Kingdom were identified. The mortality rate was 0.5 per 100,000 participants. Deaths occurred during or after the swim (3), cycle (1), and run (1) events. During the same period, 5 TRDs were identified among UK citizens competing abroad. These deaths occurred during or after the swim (2), cycle (1), and run (2) events. Cardiovascular pathology was cited as a cause or contributing factor in half of the fatalities. Four deaths were referred to a specialist cardiac pathology service for autopsy. CONCLUSIONS: Cardiovascular disease was found to be the most common cause of TRD. Further research is needed to determine the underlying cardiac pathology that triggers TRDs. With this information it may be possible to develop screening tools that can prevent similar fatalities from occurring in the future.

Wilderness Medical Society practice guidelines for the treatment of acute pain in remote environments: 2014 update.

The Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the management of pain in austere environments. Recommendations are graded on the basis of the quality of supporting evidence as defined by criteria put forth by the American College of Chest Physicians. This is an updated version of the original WMS Practice Guidelines for the Treatment of Acute Pain in Remote Environments published in Wilderness & Environmental Medicine 2014;25(1):41-49.

Wilderness Medical Society practice guidelines for the treatment of acute pain in remote environments.

The Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the management of pain in austere environments. Recommendations are graded based on the quality of supporting evidence as defined by criteria put forth by the American College of Chest Physicians.

Sleep disturbance at altitude.

PURPOSE OF REVIEW: The aim is to describe the impact of altitude upon sleep, the physiology that underpins these changes and the therapeutic solutions that are currently in place. RECENT FINDINGS: On ascending to altitude, lowland residents commonly experience some degree of sleep disturbance. Occasionally, this can prove very uncomfortable and impact upon daytime activities. Historically, the underlying cause of sleep disturbance was thought to be due to the effect of periodic breathing. However, recent research has shown that the link between periodic breathing, lighter stages of sleep and arousals is far from convincing. Instead, it appears that hypoxia has a far wider effect upon sleep at altitude than was previously thought. A number of new approaches to the treatment of sleep disturbance at altitude have recently been identified. Whereas some treat the underlying hypoxia through pharmacological or technological means, others seek to address the symptoms of sleep disturbance more directly. SUMMARY: Many of the current approaches to treating sleep disturbance at altitude have been shown to be well tolerated and successful, although few comparisons have been made. Future research is likely to focus upon matching the safest and most successful approach to the individual and their environment.

Do British commercial mountaineering expeditions carry drugs to treat high altitude illnesses?

High altitude commercial expeditions are increasingly popular. As high altitude illnesses are common on ascent to altitude, this study aimed to ascertain whether medications for these conditions were carried by commercial operators who run high altitude expeditions. Despite recommendations, it appears that drugs to treat high altitude illnesses are not routinely carried by commercial operators.

Improving sleep at altitude: a comparison of therapies.

OBJECTIVE: This study aimed to compare 3 treatment modalities during sleep at an altitude of 5300 m to identify strategies for reducing the incidence of periodic breathing at high altitude. METHODS: Fifteen trekkers, with identical ascent profiles and no signs or symptoms of altitude illness, served as subjects. All study participants arrived at 5300 m after a gradual ascent from 1300 m. On their second night at 5300 m, subjects were randomly assigned (with a computer-based random assignment procedure) to 1 of 4 different treatment groups: control (n = 4); 1 L/min O(2) via a demand system during sleep (n = 3); 1 L/min O(2)/CO(2) mix (1.5% CO(2)) via a demand system during sleep (n = 4); or 125 mg acetazolamide 30 minutes before bedtime (n = 4). Heart rate, respiration rate, blood oxygen saturation, tidal volume, minute volume, and apnea hypopnea index were measured. RESULTS: Upon comparing the 4 groups, there were no statistically significant differences between the variables. One-way analysis of variance indicated a trend toward statistical significance for SaO(2) between groups (F = 2.9, P = .08), and Tukey Honestly Significant Difference (HSD) post hoc tests indicated a trend in the SaO(2) difference between the 1 L/min oxygen and control groups (P = .07). While 1-way analysis of variance suggested no difference for respiratory rate between groups (F = 2.5, P = .1), Tukey HSD indicated a trend in statistical difference of the respiratory rate between 1 L/min O(2) and 1 L/min O(2)/CO(2) mixture (P = .08). CONCLUSIONS: These statistical trends found between control and treatment groups indicate that further study is warranted.

Raymond Greene: physician, mountaineer, and raconteur.

C. Raymond Greene (1901-1982) was a man of many talents. After graduating from medical school in 1927, he spent a decade in general practice. He subsequently became heavily involved in the emerging specialty of endocrinology and went on to gain considerable recognition in the treatment of thyroid disorders before eventually becoming involved in the world of medical publishing. Aside from Greene's mainstream vocational and intellectual pursuits, from boyhood he nurtured a passionate interest in mountaineering--first in his native Great Britain, and then the European Alps, and ultimately in the high Himalayas. His involvement in landmark climbs, such as the successful Kamet venture in 1931 and Everest attempt in 1933, earned him a place in the pantheon of Himalayan explorers and mountaineers and stimulated Green's interest in high altitude physiology and medicine. He made notable additions to the literature on this subject in publications such as Nature and Journal of Physiology. Apart from his remarkable life achievements in the areas of medicine, mountaineering, and publishing, Greene was perhaps best remembered by those close to him (and by contemporary readers who are devotees of his writing) as a peerless storyteller with a sardonic sense of irony.

Are UK commercial expeditions complying with wilderness medical society guidelines on ascent rates to altitude?

The incidence of acute mountain sickness can be reduced by ascending slowly to altitude. We compared a recommended ascent rate with those offered by commercial companies to three of the most popular high-altitude destinations in the world. While the majority complied with the recommended ascent rate, ascents on Kilimanjaro did not.

A review of electrocardiography in the high altitude environment.

An ascent to altitude places considerable demands on the cardiovascular system. Changes in the rate, rhythm, and morphology of the electrocardiogram reflect the fall in the partial pressure of inspired oxygen (PiO2) and the adaptive responses that the human body makes. The effect of hypoxia on the autonomic nervous system results in changes to the heart rate during rest and exercise. Although this is raised during rest and submaximal exercise, maximal heart rate at altitude is reduced as a result of changes in parasympathetic activity. Hypoxic pulmonary vasoconstriction leads to a rise in pulmonary artery pressure and morphological changes on the electrocardiogram. Right axis deviation, right bundle branch block, and changes to P and T wave amplitudes are commonly found on ascent and resolve only after a return to low altitude. Although atrial and ventricular ectopic activity is also common, tachyarrhythmias are rare in healthy individuals. However, in those with significant cardiac disease, the hypoxic environment can be hazardous, exposing individuals to ischemia and the risk of sudden cardiac death.

The Snow Snorkel: a proof of concept study.

OBJECTIVE: To demonstrate that the Snow Snorkel can be used safely by healthy volunteers buried in snow for up to 1 hour. METHODS: Nine healthy male volunteers were placed in a shoulder-width trench and buried with snow to a depth of 30 to 40 cm. The study was divided into 2 stages. The first stage (Stage 1) was performed with the Snow Snorkel in operation (60-minute duration) and was then followed by a second stage (Stage 2) (15-minute duration) when the device was removed. Arterial oxygen saturation (SaO2), heart rate (HR), respiratory rate (RR), axillary temperature (T), and 3-lead electrocardiography (ECG) were monitored throughout the study. RESULTS: Of the 9 volunteers who were enrolled, 7 were able to complete Stage 1, while only 3 were able to complete Stage 2. In those who completed Stage 1, the mean HR fell by 14.1 beats/min (P = .002), while RR (P = .5) and SaO2 (P = .7) remained unchanged compared to baseline measurements. There were no changes in T or ECG. CONCLUSIONS: Simple systems such as the Snow Snorkel are effective during snow burial and warrant further investigation.