Occurrence of Acute Mountain Sickness in Nonclimbing Tourists at Mount Mitchell,North Carolina (2037 m)

Altitude sickness research is often focused on high-altitude pulmonary edema/high-altitude cerebral edema or acute mountain sickness (AMS) progression at altitudes well above 2400 m with most altitude research being observational studies of trained mountaineers at high (>3000 m) to extreme altitudes (>5000 m) (Schommer and Bartsch, 2011). Therefore, relatively little is known about the prevalence of AMS at low to moderate altitudes (around 2000 m) in nontrained visitors to altitudes higher than where they reside. Most literature states that AMS develops above 2400 m (Hackett and Roach, 2001; Schommer and Bartsch, 2011). Stream et al. (2009) give a potential altitude of around 2000 m, whereas Hackett and Roach (2001) state it is unusual for AMS to occur as low as 2000 m. In general, the incidence of identified AMS increases between 1500 and 2500 m (Basnyat and Murdoch, 2003).

We set out to determine whether AMS occurs at 2000 m in nonmountaineers with consideration to ambient barometric pressure. Data collection was conducted at Mt. Mitchell located within the Black Mountains of the Blue Ridge region of the Appalachians of western North Carolina. At 2037 m, it is the highest point in the United States east of the Mississippi River and draws thousands of visitors a year from the heavily traveled Blue Ridge Parkway. The summit is accessible through an auto road and paved quarter-mile walking path, allowing for a rapid ascent profile. All methods were consistent with the University of Nebraska at Kearney Institutional Review Board (IRB) guidelines (IRB #061013-1), including informed consent parameters.

A total of 316 men and nonpregnant women aged 19 years and older were surveyed with the Lake Louise Questionnaire (LLQ) as they were leaving the summit area; 190 on days with normal-high barometric pressure (≥593 mmHg) and 126 on days with low barometric pressure (<593 mmHg). Of those surveyed, 16 individuals were disqualified due to either migraine (n = 14) or alcohol consumption in the past 12 hours (n = 2). Only two individuals displayed potential AMS symptoms, and one of those individuals was disqualified due to migraine. Subjects were asked how long they remained at the summit area and all spent <1 hour. This shows that the typical nonmountaineer visitor spends very little time at moderate altitude summits resulting in very limited expected potential cases of AMS.

These results demonstrate that, even on days with low barometric pressure, AMS will not predictably occur in casual nonclimbing day visitors spending <1 hour at the summit of Mt. Mitchell, NC (2037 m), or similar altitudes, in accordance with the LLQ.