Abstract
To the Editor:
Dr. Hillebrandt has written a thoughtful letter to the editor in response to the recently released Wilderness Medical Society Guidelines for the Prevention and Treatment of Acute Altitude Illness. We appreciate his praise of the Guidelines and agree wholeheartedly that improved cooperation between the WMS, UIAA, ICAR, and International Society for Mountain Medicine (ISMM) is desirable.
Dr. Hillebrandt presented his opinion about several key differences between the approach taken by the WMS and that taken by the UIAA and ICAR. After careful consideration, we do not agree with some of his comments. We believe that grading the quality of evidence and publishing references is very important, because it allows improved substantiation of recommendations and claims. Readers should have the opportunity to understand the quality of the evidence underlying assertions, be in a position to assess the potential for bias, and be able to access supporting evidence if they so desire. Motivated learners will seek to understand where evidence is strong or weak in order to make informed decisions about the integrity of data and their application to behavior and therapeutic activities.
Dr. Hillebrandt's concern about hypoxia interfering with a physician or lay person's ability to make accurate diagnoses may apply at extreme altitudes, but is less applicable at lower elevations, such as those of ski resorts in Colorado or the Alps. The UIAA's recommendation referred to by Dr. Hillebrandt to routinely administer 3 drugs (acetazolamide, dexamethasone, and nifedipine) to ill patients at high altitude lacks supporting evidence. Such a recommendation is precisely why we made the effort to review the literature and provide a rationale for therapy based on a more tailored approach. We do not believe that guidelines should be written at the functional level of providers with altered mental status, as Dr. Hillebrandt suggests, particularly given the lack of evidence for hypoxia-induced altered mental status interfering with physicians' judgment at high altitude.
Dr. Hillebrandt criticizes the WMS approach to descent in the treatment of altitude illness. Contrary to his statement, we do not encourage people to remain at altitude. Rather, we present specific circumstances in which remaining at the same altitude, rather than descending, is in our opinion a valid option. Given the prevalence of mild to moderate AMS, routine insistence on mandatory descent to lower elevations, even in remote areas, may lead to inappropriate disruptions of travel plans or premature termination of trips. If individuals who elect to remain at the same elevation know when descent is indicated—a point made in our guidelines—remaining at the same elevation while treating mild to moderate AMS is a reasonable option.
Dr. Hillebrandt also opines that we have placed too great an emphasis on pharmacologic strategies. Our guidelines place appropriate emphasis on the role of slow ascent (which has actually not been well studied at high altitude), but recognize that there are certain situations (Table 3 of the Guidelines) in which slow ascent may either not be feasible or insufficient to prevent altitude illness. We do not seek to legitimize the practices of guides who take their clients up to high elevations at too rapid a rate on Kilimanjaro and other peaks. Rather, we are simply recognizing the realities of what happens in the field and providing travelers with viable alternatives to mitigate risk when they lack other means for doing so.
Ideally, the Guidelines will encourage others to better understand the origins of recommendations for therapies and to be circumspect about the opinions they espouse. We support the notion put forth by Dr. Hillebrandt that it would be nice to never need to prevent or treat altitude-related illnesses, or to always keep it simple, but that is not reality.