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The meeting began with updates from major laboratory and expedition-based research groups from across the United Kingdom, including the BMRES, Xtreme Everest/CASE (Centre for Altitude, Space and Extreme environment medicine, University College London), Extremes Research Group (University of Bangor), APEX (Altitude Physiology Expeditions), and Medex. Professor Chris Imray (University Hospitals Coventry and Warwickshire NHS Trust) provided a brief overview of opportunities for further study, including the Diploma of Mountain Medicine, which has recently been adopted by the Faculty of Pre-Hospital Care, and emerging qualifications including the International Diploma in Expedition and Wilderness Medicine (Royal College of Physicians and Surgeons of Glasgow) and Masters in Extreme Medicine (University of Exeter).
“Breathing and the brain” was the theme of the next session. Dr. George Balanos (University of Birmingham) presented recent work demonstrating that a brief period of negative airway pressure may offer a potential treatment for sleep apnea. Dr. Matthew Rowland (University of Oxford) shared advances in hypoxic brain imaging and Dr. Olivia Faull (University of Oxford) described processing of breathing in athletes. During a hypercapnic ventilatory response test, athletes (who were operating closer to their maximal ventilatory capacity) showed greater breathlessness anxiety than matched sedentary controls. Professor Mark Wilson (Imperial College London) explained the influence of the venous system on intracranial pressure; limitations in venous drainage may play a particular role in the development of high-altitude headache.
Major David Holdsworth (Royal Army Medical Corps) concluded the morning with a report from the British Services Dhaulagiri Medical Research Expedition 2016. Implantable loop recorders in the 16 members of the climbing teams revealed arrhythmias in two-thirds of these otherwise fit individuals during their ascent to extreme high altitude, and an association between heart rate variability and acclimatization. The expedition also highlighted the importance of redundancy in the electrical power plan, refrigeration of samples, and communications systems. Backup solar panels and solar charged batteries proved invaluable adjuncts to generators and liquid nitrogen freezers.
The afternoon began with a tribute to Ron Fletcher, a much-respected member of BMRES. Ron was the Medical Officer on the first BMRES expedition to the Himalayas in 1977 and latterly the society's treasurer.
A spirited oral presentation session followed, with Susie Bradwell (University College London) awarded first prize for her presentation of data showing no effect of losartan on exercise proteinuria. Dr. Alex Clarke (Newcastle Hospitals NHS Foundation Trust) came runner up with his report that losartan may attenuate high-altitude sleep disturbance. Other notable presentations included preliminary findings suggesting that beetroot juice supplementation may have an adverse effect on exercise capacity in hypoxia, by Gabriella Rossetti (University of Bangor). Dr. Jeremy Windsor (Xtreme Everest) shared observations of prolonged ventricular repolarization in healthy adult males at high altitude and Professor John Coote (University of Birmingham) reported that salivary corticotrophin releasing hormone concentration may predict acute mountain sickness (AMS) susceptibility. Posters were presented on a range of subjects including evidence-based frostbite management, AMS prediction tools, point-of-care testing at 5000 m, and the effects of altitude on visual fields, respiratory rate, cognitive function, and risk-taking behavior.
In the final session of the day, adaptation in Sherpa was discussed by Dr. Ned Gilbert-Kawai (Xtreme Everest), who drew attention to some of the evolutionary advantages that this unique population group exhibits at high altitude. Distinction between Sherpa and highland Andean evolutionary strategies was explored, while acknowledging that highland Ethiopian populations are less well studied than the former two groups. Professor Jo Bradwell (BMRES) presented recent data suggesting that acetazolamide may inhibit exercise performance in older age, speculating that dosage may require adjustment in those with reduced renal function and that further research is required to deliver evidence-based guidelines.
Dr. Lucy Hawkes (University of Exeter) ended the day's formal proceedings with a fascinating and entertaining lecture on the Bar-headed Goose, whose performance in conditions of severe oxygen deprivation exceeds even the hardiest of human highlanders. Its unidirectional ventilatory system, unrivalled capillary density, and meteorological insight are just some of the advantages that permit the bird's legendary migration over the Tibetan Plateau, a supposed example of geologically driven evolutionary pressures.
Dr. Alex Wright and Amy Cogswell were thanked for their hard work in organizing the conference. The day concluded with a dinner in the sky room of the conference venue to celebrate 40 years of BMRES.