Oximetry fails to predict acute mountain sickness or summit success during a rapid ascent to 5640 meters.
OBJECTIVE
The purpose of this study was to determine whether arterial oxygen saturation (Spo(2)) 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 Spo(2) were collected on arrival at the hut and repeated immediately before and after the climbers' summit attempts.


RESULTS
Average Spo(2) 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 Spo(2) was not significantly different between those who experienced AMS and those who did not (P = .82); neither was there a difference in Spo(2) 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 Spo(2) does not appear to be predictive of AMS or summit success during rapid ascents.
Human Movement Science Program, HPER Department, Utah State University, Logan, UT 84322-7000, USA. dale.wagner@usu.edu
Dale R
DR
Wagner
Jonathan R
JR
Knott
Jack P
JP
Fry
D000064:Acclimatization / Q000502:physiology; D000328:Adult; D000532:Altitude Sickness / Q000097:blood* / Q000453:epidemiology; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D009051:Mountaineering; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology*
D010100:Oxygen