Oximetry Fails to Predict Acute Mountain Sickness or Summit Success During a Rapid Ascent to 5640 Meters

• Published in: Wilderness & environmental medicine Vol. 23; no. 2; pp. 114 - 121
• Main Authors: Wagner, Dale R., PhD, Knott, Jonathan R., MS, Fry, Jack P., BS
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2012
• Subjects: Acclimatization - physiology; Adult; Altitude Sickness - blood; Altitude Sickness - epidemiology; AMS; arterial oxygen saturation; Emergency; Exercise Tolerance - physiology; Female; heart rate; Heart Rate - physiology; high altitude; Humans; hypoxia; Male; Mountaineering; Oximetry; Oxygen - blood; Oxygen Consumption - physiology; hypoxia; heart rate; high altitude; arterial oxygen saturation; mountaineering; AMS
• ISSN: 1080-6032; 1545-1534
• DOI: 10.1016/j.wem.2012.02.015

Objective The purpose of this study was to determine whether arterial oxygen saturation (Sp o2 ) and heart rate (HR), as measured by a finger pulse oximeter on rapid arrival to 4260 m, could be predictive of acute mountain sickness (AMS) or summit success on a climb to 5640 m. Methods Climbers (35.0 ± 10.1 years; 51 men, 5 women) were transported from 2650 m to the Piedra Grande hut at 4260 m on Pico de Orizaba within 2 hours. After a median time of 10 hours at the hut, they climbed toward the summit (5640 m) and returned, with a median trip time of 14 hours. The Lake Louise Self-Assessment Scale (LLSS) for AMS, HR, and Sp o2 were collected on arrival at the hut and repeated immediately before and after the climbers' summit attempts. Results Average Sp o2 for all participants at 4260 m before their departure for the summit was 84.4% ± 3.7%. Thirty-seven of the 56 participants reached the summit, and 59% of all climbers met the criteria for AMS during the ascent. The Sp o2 was not significantly different between those who experienced AMS and those who did not ( P = .82); neither was there a difference in Sp o2 between summiteers and nonsummiteers ( P = .44). Climbers' HR just before the summit attempt was not related to AMS but was significantly lower for summiteers vs nonsummiteers ( P = .04). Conclusions The Sp o2 does not appear to be predictive of AMS or summit success during rapid ascents.