Work in Hypoxic Conditions-Consensus Statement of the Medical Commission of the Union Internationale des Associations d'Alpinisme (UIAA MedCom)

Abstract

Objectives: The Commission gives recommendations on how to provide health and safety for employees in different kinds of low oxygen atmospheres. So far, no recommendations exist that take into account the several factors we have outlined in this report.Methods: The health and safety recommendations of several countries were analysed for their strength and deficiencies. The scientific literature was checked (Medline, etc.) and evaluated for relevance of the topic. Typical situations of work in hypoxia were defined and their specific risks described. Specific recommendations are provided for any of these situations.Results: We defined four main groups with some subgroups (main risk in brackets): short exposure (pressure change), limited exposure (acute altitude disease), expatriates (chronic altitude disease), and high-altitude populations (re-entry pulmonary oedema). For healthy unacclimatized persons, an acute but limited exposure down to 13% O 2 does not cause a health risk. Employees should be advised to leave hypoxic areas for any break, if possible. Detailed advice is given for any other situation and pre-existing diseases.Conclusions: If the specific risk of the respective type of hypoxia is taken into account, a pragmatic approach to provide health and safety for employees is possible. In contrast to other occupational exposures, a repeated exposure as often as possible is of benefit as it causes partial acclimatization. The consensus statement was approved by written consent in lieu of a meeting in July 2009.

Advantages and challenges with using hypoxic air venting as fire protection

“…Health aspects with respect to a reduction in oxygen in the atmosphere are not the expertise of the authors, and the subject is just discussed briefly in terms of findings in the literature. Further information on the topic can be found in the literature [7,35,[44][45][46][47]. Table III summarizes different symptoms at different oxygen concentrations; it should be mentioned that depending on the reference, the symptoms at different oxygen concentrations varies a little.…”

“…However, the most important parameters are the oxygen concentration and duration of exposure but also disease, physical fitness, age, and sex are important parameters [35]. Küpper et al [46] stated that an acute but limited exposure down to 13% oxygen concentration does not cause a health risk if the persons are healthy; hence, this could be interpreted as a limit. Further, they pointed out that employees in a reduced oxygen atmosphere for fire prevention purposes can leave the room immediately if they do not feel well [46].…”

“…Küpper et al [46] stated that an acute but limited exposure down to 13% oxygen concentration does not cause a health risk if the persons are healthy; hence, this could be interpreted as a limit. Further, they pointed out that employees in a reduced oxygen atmosphere for fire prevention purposes can leave the room immediately if they do not feel well [46]. Burtscher et al [45] stated that people without severe illnesses, a health risk is unlikely at greater than 14.5% oxygen concentration.…”

Defining the critical hypoxic threshold that promotes vascular remodeling in the brain

“…This is an important issue because most animal studies to date have employed fairly severe levels of hypoxia, e.g. : 8% O 2 , which is equivalent to an altitude of 23,500 feet, conditions that are not practical or tolerable for most humans (Kupper et al 2011). So before considering the clinical potential of this approach in human patients, it is important to define the mildest level of hypoxia that promotes beneficial remodeling.…”