Increase in Older Adults Reporting Mountaineering-Related Injury or Illness in the United States, 1973–2010

WILDERNESS & ENVIRONMENTAL MEDICINE, 24, 86 – 89 (2013)

Letters to the Editor Increase in Older Adults Reporting Mountaineering-Related Injury or Illness in the United States, 1973–2010 To the Editor: Older adults are a growing injury population in the United States.1 We analyzed US climbing and mountaineering-related injuries and illness including fatalities recorded in Accidents in North American Mountaineering2 as an indirect assessment of changes during the past several decades in the proportion of older adults involved in mountaineering accidents. Statistical tables from this source summarize mountaineering accidents occurring in the United States from 1951 to 2010. From 1973 onward, cases were grouped into 7 age categories, with the oldest age group being individuals older than 50. Before 1973, the oldest age group recognized was individuals older than 35. Data from Canada were not included in the analysis because data were not available from 2006 onward. Cases are identified by the editors of Accidents in North American Mountaineering for possible inclusion in the tables in a number of ways. The most common means of case identification are reports submitted by climbers and members of search and rescue organizations. In national parks with a large volume of climbing activity (eg, Yosemite, Denali, Grand Teton), accident reports are submitted by climbing rangers. During the past decade, cases have also been identified by editors using searches of online sources including general climbing websites such as The Mountain Project (www.themountainproject.com) and Supertopo (www.supertopo.com) as well as area-specific websites (eg, www.redriverclimbing.org). Cases are included in the statistical tables and used for this analysis if they occur in the United States and involved people participating in climbing and mountaineering activities including rock or ice climbing, mountain climbing, and ski mountaineering. Duplicate recording of cases is avoided because the details of each case are reviewed by the editor. Accidents occurring during bouldering, climbing indoors, or climbing buildings are not included in the tables used for this analysis. We calculated the annual percentage of cases involving individuals older than 50 by dividing the number of individuals older than 50 by the total number of individuals of known age; individuals of unknown age were not included in the denominator. Temporal changes in the percentage of cases occurring in individuals older than 50 are summarized and pre-

sented graphically for years 1973 through 2010. For descriptive purposes, a loess procedure was used to fit a locally weighted regression line and graphed using SigmaPlot 12 (Systat Software Inc, Chicago, IL). Between 1973 and 2010, there were 6603 US climbing and mountaineering accidents reported; 1281 (19%) of these were fatalities. Most accidents occurred on rock (63%) as opposed to snow or ice (37%); during ascent (77%); and during the months of June, July, August, and September (63%). More than half of the US accidents occurred in California (21%), Washington (18%), and Colorado (12%). For years in which type of accident was recorded (1984 –2010), the most common types of accident were injury (83%), frostbite or hypothermia (6%), and altitude-related illness (3%). Of the 6603 accidents reported, age was known for 5513 cases (83%). The number of accidents involving climbers older than 50 each year ranged from 0 in 1975 to 31 in 2010. Among the 5513 cases for which the age of the victim was known, the percentage of injured climbers older than 50 ranged from 0% in 1975 to 22% in 2008 (Figure). The mean percentage of injuries or fatalities occurring in individuals older than 50 increased from 3% between 1973 and 1989 to 16% between 2006 and 2010. We observe a large increase in the percentage of adults older than 50 with mountaineering-related injury or ill-

Figure. Percentage of US mountaineering-related injuries and illnesses involving climbers older than 50 reported in Accidents in North American Mountaineering, 1973–2010.2

Letters to the Editor ness as reported during the last 4 decades in Accidents in North American Mountaineering. Accidents in North American Mountaineering depends on the voluntary submission of information by injured parties and rescuers and captures only a fraction of the total number of US mountaineering accidents. Further, the purpose of these reports is to understand the etiology of injuries, not to quantify the total number of injuries occurring each year. As a result, the data used for this analysis do not represent the actual number of accidents that occurred each year, and interpretation of trends from this source of data must be made with caution. Additionally, changes in reporting practices with time have the potential to introduce bias in temporal trends. Despite these important limitations, we think the observed trend is not simply a result of changes in reporting practices. Increased use of Internet-based communication would not be anticipated to favor older adults. Similarly, although reporting of accidents by climbing rangers from national parks may be biased toward older climbers, we would not expect that such a bias would favor reports regarding older adults during the past decade but not in the 1970s and 1980s. Given the magnitude of the change observed and its agreement with trends in other forms of recreational trauma in older adults,3,4 we think it likely that the observed increase in reporting in Accidents in North American Mountaineering represents an actual increase in the number of older US adults experiencing climbing or mountaineering-related injury or illness. Between 1980 and 2010, the percentage of the US population age 50 and older increased from 26% to 32%.5 Thus, the approximately fivefold increase in reports of older adults experiencing mountaineering accidents from Accidents in North American Mountaineering during the same time is not explained solely by the increase in the population of older adults. We think that the most likely explanation for the observed trend is a disproportionate increase in mountaineering activity by older adults. Whether this increase reflects a general increase in climbing activities of older adults that will be sustained or reflects the aging of a cohort that began climbing in the 1970s is unknown. The data presented are not coupled with information about the age distribution of participants in climbing and mountaineering activities, so our analysis is unable to determine the rate of accidents in older vs younger adults. However, even if the risk of injury is lower in older than younger climbers,6 the results suggest that older adults are now a substantial US climbing and mountaineering accident population.

87 If representative of actual trends in the epidemiology of mountaineering accidents, these findings are important because age is a risk factor for adverse outcomes after trauma.7–9 Further, because targeted education and additional rescue resources can reduce mountaineering-related fatalities,10 a better understanding of these trends has potential implications for prevention and rescue preparedness. Further work is needed to confirm these observations and, if confirmed, to identify and implement practices to minimize mountaineering-related injury and illness in older adults. The National Center for Research Resources had no role in the design and conduct of the study; the collection, management, analysis, and interpretation of the data; or the preparation, review, or approval of the manuscript.

Acknowledgments This study was supported by National Center for Research Resources through grant KL2TR000084 (Dr Platts-Mills). Thanks to Mark Weaver for advice on statistical analyses; Robert Lewis for comments on mountaineering rescues involving older adults; and Jed Williamson and the American Alpine Club for permission to use the Accidents in North American Mountaineering data. Timothy F. Platts-Mills, MD Department of Emergency Medicine University of North Carolina Chapel Hill, NC Katherine M. Hunold Departments of Biostatistics University of North Carolina Chapel Hill, NC

References 1. Shinoda-Tagawa T, Clark DE. Trends in hospitalization after injury: older women are displacing young men. Inj Prev. 2003;9:214 –219. 2. Accidents in North American Mountaineering Statistical Tables. 1973–2010. Available at: http://www.americanalpineclub.org/p/ anam-statistics. Accessed August 15, 2012. 3. Helmkamp JC, Carter MW. ATV deaths among older adults in West Virginia: evidence suggesting that “60 is the new 40!” South Med J. 2009;102:465– 469. 4. Ekman R, Welander G, Svanström L, Schelp L, Santesson P. Bicycle-related injuries among the elderly—a new epidemic? Public Health. 2001;115:38 – 43.

88 5. Annual estimates of the resident population by sex and five-year age groups for the United States. 2012. Available at: http://www.census.gov/compendia/statab/2012/tables/ 12s0007.pdf. Accessed August 22, 2012. 6. Backe S, Ericson L, Janson S, Timpka T. Rock climbing injury rates and associated risk factors in a general climbing population. Scand J Med Sci Sports. 2009;19:850 – 856. 7. Hollis S, Lecky F, Yates DW, Woodford M. The effect of pre-existing medical conditions and age on mortality after injury. J Trauma. 2006;61:1255–1260. 8. Holcomb JB, McMullin NR, Kozar RA, Lygas MH, Moore FA. Morbidity from rib fractures increases after age 45. J Am Coll Surg. 2003;196:549 –555. 9. Mosenthal AC, Lavery RF, Addis M, et al. Isolated traumatic brain injury: age is an independent predictor of mortality and early outcome. J Trauma. 2002;52: 907–911. 10. McIntosh SE, Campbell AD, Dow J, Grissom CK. Mountaineering fatalities on Denali. High Alt Med Biol. 2008;9:89 –95.

Pituitary Apoplexy Masquerading as Acute Mountain Sickness To the Editor: Classical pituitary apoplexy is a medical emergency, and rapid replacement with hydrocortisone may be lifesaving. It is a clinical syndrome characterized by sudden onset of headache, vomiting, visual impairment, and decreased consciousness caused by hemorrhage or infarction of the pituitary gland. The headache may or may not be accompanied by neurologic symptoms involving the second, third, fourth, and sixth cranial nerves.1 The diagnosis is frequently missed because of its rarity. A high index of suspicion is required to diagnose these cases, as illustrated by this case report. A 29-year-old man with no prior history of high altitude exposure ascended to 5200 m over the course of 14 days. Soon after arrival he experienced a severe headache that was associated with nausea, difficulty sleeping, loss of appetite, and fatigue. With this constellation of symptoms he was diagnosed with acute mountain sickness (AMS) and treated with ibuprofen 400 mg 3 times daily, acetazolamide 250 mg twice daily, and rest. During the next 4 days at 5200 m, he failed to improve and was subsequently evacuated to 1800 m for further management. The patient denied any history of drug abuse, visual disturbance, double vision, ptosis, or head trauma. Evaluation revealed a temperature of 37.0°C (98.6°F), regular pulse of 44 beats/min, blood pressure (BP) of 90/60 mm Hg, respiratory rate of 16 breaths/min, and pulse oximetry of 98% on room air. There was no neck rigidity. Eye movements were full and unrestricted, and the fundus examination was normal. The remainder of

Letters to the Editor the general physical and systemic examination was within normal limits. Routine hematologic and biochemical investigations were normal. The electrocardiogram showed sinus bradycardia, and a computed tomographic (CT) scan of the brain was normal. Persistent hypotension, sinus bradycardia, and headache gave a strong clinical clue of an acute adrenocortical insufficiency likely owing to secondary cause. The patient was started on hydrocortisone 100 mg IV every 6 hours. Within 12 hours, his BP normalized to 120/80 mm Hg and pulse to 68 beats/min. Hormonal assays were performed along with a magnetic resonance imaging (MRI) of the brain. The MRI revealed enlargement of the anterior pituitary gland with altered signal intensity in the sella extending into the suprasellar region. It measured 8.9 mm in height, 12.7 mm in anteroposterior dimension, and 14 mm in transverse plane. The gland was closely abutting the optic chiasma. There was a focal area of altered signal intensity, which was heterogeneously hyperintense on T1 and hypointense on T2, suggestive of early subacute hemorrhage. On postcontrast scans there was moderate enhancement of the gland with focal nonenhancing area within. Hormonal analysis revealed normal levels of thyroxine, thyroid-stimulating hormone, serum testosterone, prolactin, luteinizing hormone, and follicle-stimulating hormone, and a serum cortisol of 9.65 ␮g/dL (basal value) and 14.24 ␮g/dL (during hypoglycemia; range, 20 –70 ␮g/dL). The patient went on to make a complete recovery and has not required regular hormonal therapy. Pituitary adenomas predispose to apoplexy; however, the condition is usually not known or suspected at the time of the event. Numerous other medical conditions have been linked to pituitary apoplexy but many times it occurs without any predisposing factor.2,3 If present, the main predisposing factors are medication (bromocriptine and cabergoline), radiotherapy, pituitary function tests, diabetes mellitus, trauma, thrombocytopenia, or recent surgery.4 High blood pressure is also considered as a risk factor for pituitary apoplexy, although this association is not always observed.5,6 High altitude could be a risk factor in this patient as increased risk of cerebrovascular accidents at high altitude is known.7 Elsässer Imboden et al8 have underlined the superiority of MRI over CT imaging in detecting pituitary apoplexy as is demonstrated by this report as well. Pituitary apoplexy can be a masquerader for AMS or high altitude cerebral edema (HACE) if it presents at high altitude. The astute physician may distinguish these diagnoses by examining the signs and symptoms carefully. AMS occurs in a setting of recent gain in altitude, and presents with headache and at least 1 of the following symptoms: gastrointestinal (anorexia, nausea, or