Medical Projects

In addition to the climbing, EVERESTMAX are involved with two medical projects while on the mountain. The studies are being carried out by two members of the team, Andrew Sutherland and Chris Owen. Andrew is investigating the connection between an individual's rate of acclimatisation and their intra-occular pressure while Chris is studying physical fitness and activity at altitude. Both are novel studies and add yet another aspect to the EVERESTMAX expedition. For more details about the studies please see below.

Andrew Sutherland

Andrew Sutherland graduated from medical school at Edinburgh University in 1999. Since then he has continued his surgical training in Edinburgh and Oxford. In 2003 he gained his membership of the Royal College of Surgeons of England and worked in South Africa, before starting a PhD in liver transplantation in 2004. He has always had an interest in high altitude medicine and physiology and has been the expedition doctor on two high altitude research expeditions in Bolivia (www.apex-altitude.com). On these expeditions he studied more than 100 volunteers as they ascended rapidly to 5200m (17 000 feet) and he has become experienced at monitoring and treating altitude related illnesses. On the Everestmax expediton he will be conducting a small research project to investigate why some people are affected by acute mountain sickness and others not.

Chris Owen

After clinical training in optometry, Chris became interested in medical research and subsequently studied epidemiology (the study of risk factors and causes of disease) at the London School of Hygiene and Tropical Medicine. After graduating in 2000, Chris began work as a medical researcher at St. George's , University of London. He is particularly interested in whether risk of adult heart disease begins in early life (i.e. in infancy and childhood). He is also interested in studying physical activity patterns in children and factors that effect physical activity in young people (especially between certain ethnic groups), with a view to understanding the rising levels of obesity currently being seen among young people. His experience in measuring physical activity will be uniquely used to measure the team while they climb Everest.

Intra-occular pressures project (Andrew Sutherland)

Acute Mountain Sickness (AMS) affects about 50% of people who rapidly ascend to altitudes greater than 3000m. It is characterised primarily by headaches, nausea, vomiting and fatigue. It is still not understood why some people are susceptible to this condition and others not but it has been hypothesised for more than 70 years that AMS may be due to increased pressure within the skull (raised intracranial pressure). Previously it has been very difficult to test this hypothesis because in order to measure this pressure it is necessary to drill a small hole in the skull. Recently, however a non-invasive ultrasound technique for measuring intracranial pressure has been developed. The optic nerve which supplies the eye has a lining around it called the optic nerve sheath (ONS). This lining is continuous with the lining of the brain so the fluid around the brain (cerebrospinal fluid) freely communicates with the space between the optic nerve and the optic nerve sheath. When the pressure around the brain increases the optic nerve sheath swells. It is possible to measure the optic nerve sheath diameter using ultrasound and this measurement has been shown to correlate well with intracranial pressure. This technique has been used for non-invasive intracranial pressure measurement in children with hydrocephalus (fluid on the brain), and for assessing patients with head injuries attending Accident & Emergency. The advent of highly portable ultrasound machines that can be taken into the field has made this current study possible.

The study will investigate volunteers from the Everestmax expedition who are climbing Mount Everest from the north (Tibetan) side. Serial measurements of optic nerve sheath diameter (ONSD) will be taken using a portable ultrasound at a number of altitudes during their ascent. This study will allow us for the first time to determine whether intracranial pressure is increased at high altitudes, and whether any increase correlates with symptoms of acute mountain sickness.

Physical activity and fitness in the Himalayas (Chris Owen)

Introduction
Little is known about the association between physical activity and measures of fitness at increasing levels of altitude, especially at Himalayan altitudes. Differences in the association of physical activity levels with measures of fitness at increased altitude between one person and another, may partly explain why some succeed in climbing Himalayan peaks while others fail. Unfortunately, the size and weight of established equipment needed to record these measures has been prohibitively too large and heavy to be transported to high altitude. However, technological advances now mean that these measures can be obtained using equipment that is both light and easy to wear. The Everestmax expedition offers a unique opportunity to utilise these technological advances by acquiring these measures in individuals attempting to climb to altitudes above 8000 metres.

Methods
Thirteen members of the Everestmax team will attempt to climb the North Ridge of Everest (8,850 metres). In addition to measures of body size and weight, heart rate, ventilation, breathing frequency, oxygen levels in the body and markers of Acute Mountain Sickness (AMS) measured at static locations, we will be assessing physical activity objectively during the climb (from Base Camp at 5200 metres to the North Col at 7000 metres, and during summit bids) using the ActiGraph activity monitor. This monitor (which is the size of a match box, and weighs 45 grams) will be worn around the waist under protective clothing. This will provide detailed information on the intensity and duration of exercise every 5 seconds (continuously for a period up to 14 days), providing estimates of physical activity levels during the monitoring period. In addition, climbers will wear the Suunto t6 wristwatch computer. This watch will log altitude and rate of ascent or descent whilst climbing. This watch (in conjunction with a small chest strap) will also record continual measures of heart rate, breathing parameters, providing estimates of oxygen and energy consumption. The watch will also uniquely provide a non-invasive estimation of the amount of extra oxygen needed to recover from strenuous activity (so called Excess Post-exercise Oxygen Consumption). The activity monitors and watches will be charged up and operated periodically using laptops at base camp.

Conclusions
This work offers a unique opportunity to measure physical performance in relation to energy expenditure while climbing Everest. We will be able to accurately describe the decline in physical activity and increased bodily stress that occurs when climbing at increasing levels of altitude, as well as obtaining an appreciation of factors that influence recovery from undertaking such a strenuous activity. We hope that the work will be published, acknowledging Actigraph (http://www.theactigraph.com) who have provided the monitors, and funding from St. George's, University of London.

Donations to Everestmax will help support this work. For further information contact Chris Owen by email at chris@everestmax.com.