Extrait

Background and study aims High altitude pulmonary edema (HAPE – fluid accumulation in the lungs) is an illness that can cause death and can be seen in climbers when hiking at elevation higher than 3000 m. HAPE happens when trekkers ascend too quickly without giving their bodies enough time to adjust to the decrease in oxygen. HAPE happens in around 5-15% of walkers and trekkers at elevation over 4000 m. Currently, the most commonly used drug to treat HAPE sometimes causes headache, which can worsen the problem rather than improve it. Acetazolamide is a drug used to fight similar sicknesses to HAPE like acute mountain sickness (AMS – flu or hangover signs caused by low oxygen levels) and high altitude cerebral edema (HACE – swelling of brain tissue from fluid leakage). Acetazolamide is not expensive and is commonly used. However, there have been no human studies to see if acetazolamide could be used to fight HAPE. The goal of this study is to see if acetazolamide can prevent HAPE in climbers at high elevation, to see if acetazolamide will reduce lung artery pressure, and to observe AMS, HAPE and HACE in climbers. Who can participate? The study aims to recruit 500 healthy adults between the ages of 18 and 65, male or female, non-Nepali, and without AMS already. Adults may not be already taking any drug for the prevention of altitude illness. Adults will be recruited while on their way to Everest Base Camp or Kala Patthar, between the villages of Pheriche/Dingboche and Lobuje. What does the study involve? Volunteers will be randomly allocated into one of two groups. One group will receive a four-day supply of 250 mg of acetazolamide to be taken twice per day, and the other group will receive a dummy drug (placebo). Volunteers will be recruited at Pheriche, at elevation of 4300 m, and basic vital signs will be measured at that time. Vital signs will be measured again between 36-96 hours after having taken acetazolamide in Lobuje, at elevation of 5000 m. A variety of other tests will be also be conducted before and after having taken the study drug: a questionnaire testing for signs of altitude sickness, amount of oxygen in the volunteer’s blood, blood pressure, heart rate, lung examination via stethoscope, and examination of heart vessels through sound waves. Data will also be collected on the kinds of people participating in the study at the enrolment site. Examples of body signs asked for on the questionnaire include chest tightness, coughing and tiredness. The tests conducted will show whether trekkers have AMS, HAPE or HACE and if so, the seriousness of the sickness. What are the possible benefits and risks of participating? Possible side effects of acetazolamide include tingling feeling of the skin, more urination than normal, and indigestion – allergic reactions are extremely rare. The study will give all participants access to medical care for at least 24 hours after taking the drug. This research team has a strong safety record working with trekkers in the Everest region, with three studies since 2002 using similar protocols. Only two people out of a total of 1065 trial participants in those three studies needed care due to mild rashes from acetazolamide. Where is the study run from? The study is run by researchers at the Oxford University Clinical Research Unit (Nepal), Himalayan Rescue Association/Nepal International Clinic (Nepal) and Stanford University (California, USA). When is study starting and how long is it expected to run for? The study ran from October to November 2006 for a total of 2 months. The study has been completed. Who is funding the study? The Wellcome Trust (UK). Who is the main contact? The Clinical Trials Unit at the Oxford University Clinical Research Unit – Viet Nam. +84839241983

Critère d'inclusion

• high altitude pulmonary edema

Liens

• isrctn
• ictrp