Anesthesiological Management in a Non-accessible Environment Preparation of Volunteers for Investigations with Controlled Hypoxemia in a 3 Tesla Magnetic Field for Assessing Cerebral Energy Metabolism

摘要

Several centres worldwide have established controlled hypoxemia studies (CHS) for testing and calibrating pulse oximeters. Since the brain is, compared to the rest of the body, a highly demanding organ that requires nearly 20 % of the body's total oxygen supply, a period of hypoxemia may reduce the content of high energy phosphates such as phospho-creatine (PCr) with constant levels of adenosine triphosphate (ATP). To prove this hypothesis a controlled 30 minute hy-poxemic state of 70 to75 % arterial oxygen saturation was induced in healthy subjects. "P magnetic resonance spectros-copy (3IP-MRS) performed in a 3Tesla (T)-MR-scanner was used for high energy phosphates measurement. The study protocol was based on a randomised trial including two groups of male volunteers, one with normal weight and one with a body mass index higher than 30 kg/m2 in such a way that each person served as his own control in one session with normoxe-mia and one with hypoxemia. The knowledge of physiological adjustment to a hypoxemia as well as the volunteer management is the basis for a safe procedure.