Optimization Strategy for the Prevention of AMS by RIPC Combined With Acetazolamide

The current measures to prevent acute mountain sickness (AMS) mainly include drug prevention and non-drug prevention. Acetazolamide is a drug approved by the U.S. FDA for the prevention and treatment of AMS. Remote limb ischemic preconditioning (RIPC) can also reduce the incidence of AMS as a non-durg method, with a strategy of 2 times/day training for 1 week reducing the incidence of AMS in 6 hours from 40% to 30%. The objective of this study is to determine whether rapid RIPC training combined with acetazolamide can further reduce the incidence of AMS. In this study, subjects will be divided into 5 groups: medicine group (acetazolamid 125mg bid, 2 days before entering the hypoxic room), RIPC group (RIPC training twice daily, 6 days before entering the hypoxic room), rapid RIPC group (RIPC training forth daily, 3 days before entering the hypoxic room), combined group (rapid RIPC training plus acetazolamide) and controlled group. RIPC training, completed by Renqiao Remote Ischemic Conditioning Device (Doctormate®), will be comprised of 5 cycles of bilateral upper limb ischemia and reperfusion, which will be induced by 2 cuffs placed around the upper arms respectively and inflated to 200mmHg for 5 minutes followed by 5 minutes of reperfusion by cuff deflation. After the intervention, subjects will be exposed to 4500m altitude in a normobaric hypoxic chamber for 6 hours. The incidence of AMS and other data will be compared between groups.

Inclusion criteria

• People who live in plain areas all year round and have not been to an altitude of 1500 meters or more in the past 30 days;
• Sign the informed consent form voluntarily.

Exclusion criteria

• Chronic physical or mental diseases, including hypertension, diabetes, coronary heart disease, cerebrovascular disease, chronic obstructive pulmonary disease, migraine, anxiety, depression, insomnia, etc.;
• The female is pregnant or in the period of preparing for pregnancy or breast-feeding;
• Have a history of smoking;
• Have a history of thrombosis in the upper limbs;
• Severe damage to local soft tissues of upper limbs, fractures, etc.;
• Allergic to sulfa;
• Are taking one or more drugs;
• Past laboratory tests suggest hypokalemia, hyponatremia, or liver and kidney damage;
• Patients unsuitable for enrollment in the clinical trial according to investigators decision making.