Pulse oximetry at high altitude.
ABSTRACT Pulse oximetry is a valuable, noninvasive, diagnostic tool for the evaluation of ill individuals at high altitude and is also being increasingly used to monitor the well-being of individuals traveling on high altitude expeditions. Although the devices are simple to use, data output may be inaccurate or hard to interpret in certain situations, which could lead to inappropriate clinical decisions. The purpose of this review is to consider such issues in greater detail. After examining the operating principles of pulse oximetry, we describe the available devices and the potential uses of oximetry at high altitude. We then consider the pitfalls of pulse oximetry in this environment and provide recommendations about how to deal with these issues. Device users should recognize that oxygen saturation changes rapidly in response to small changes in oxygen tensions at high altitude and that device accuracy declines with arterial oxygen saturations of less than 80%. The normal oxygen saturation at a given elevation may not be known with certainty and should be viewed as a range of values, rather than a specific number. For these reasons, clinical decisions should not be based on small differences in saturation over time or among individuals. Effort should also be made to minimize factors that cause measurement errors, including cold extremities, excess ambient light, and ill-fitting oximeter probes. Attention to these and other issues will help the users of these devices to apply them in appropriate situations and to minimize erroneous clinical decisions.
- SourceAvailable from: Buddha Basnyat
- "The list of medical problems and medications of the pilgrims needs to be properly written out in legible writing in English, Hindi, or Nepali (as the case may be) which the pilgrims need to carry in person. A simple, hand-held pulse oximeter may be useful in evaluating a pilgrim with the symptoms of altitude illness or to monitor pilgrims with cardiopulmonary problems, although pitfalls in their use need to be noted (Luks and Swenson, 2011). Finally, since pilgrimages are often a family journey, AMS prevention programs should be targeted both at parents and children. "
Article: High Altitude Pilgrimage Medicine[Show abstract] [Hide abstract]
ABSTRACT: Abstract Religious pilgrims have been going to high altitude pilgrimages long before trekkers and climbers sojourned in high altitude regions, but the medical literature about high altitude pilgrimage is sparse. Gosainkunda Lake (4300 m) near Kathmandu, Nepal, and Shri Amarnath Yatra (3800 m) in Sri Nagar, Kashmir, India, are the two sites in the Himalayas from where the majority of published reports of high altitude pilgrimage have originated. Almost all travels to high altitude pilgrimages are characterized by very rapid ascents by large congregations, leading to high rates of acute mountain sickness (AMS). In addition, epidemiological studies of pilgrims from Gosainkunda Lake show that some of the important risk factors for AMS in pilgrims are female sex and older age group. Studies based on the Shri Amarnath Yatra pilgrims show that coronary artery disease, complications of diabetes, and peptic ulcer disease are some of the common, important reasons for admission to hospital during the trip. In this review, the studies that have reported these and other relevant findings will be discussed and appropriate suggestions made to improve pilgrims' safety at high altitude.High Altitude Medicine & Biology 10/2014; 15(4). DOI:10.1089/ham.2014.1088 · 1.82 Impact Factor
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ABSTRACT: Rapid ascent to altitude can result in the development of high altitude illnesses such as acute mountain sickness (AMS). This study aimed to investigate AMS symptoms in adolescents and study basic cardiopulmonary measurements at altitude. Thirty-eight adolescents aged 16 to 19 years flew to 3500 m from 215 m and continued over a 23-day period to ascend to a maximum altitude of 5200 m. Each member of the expedition completed a Lake Louise Self-Assessment Questionnaire (LLSAQ) on a daily basis, and AMS was defined as a score of ≥ 3, with an associated headache. Physiology measurements included a step test, and both before and after exercise pulse oximetry, blood pressure, and pulse rate. Oxygen saturation inversely correlated with altitude (P = .001). Mean pulse rate increased from 70 beats/min (± 6.5) at 215 m to 83 beats/min (± 2.2) at 3500 m (P = .01), and a rise in blood pressure with ascent was highlighted (P = .004). The majority of subjects (84%) had an LLSAQ of 3 or more on at least 1 occasion, and they tended to record higher pulse rates (P = .005) and lower oxygen saturations (P = .001). Exercise-induced drops in oxygen saturation and raised pulse rates were more prolonged in subjects with severe AMS compared with subjects not having AMS (P = .046 and P = .005, respectively). The LLSAQ scoring system appeared to be a simple and effective technique to aid the diagnosis of adolescents who have AMS, and it may help improve the safety of large groups traveling to altitude. The AMS subjects tended to have low oxygen saturations and high pulse rates, highlighting potential areas for further research.Wilderness and Environmental Medicine 03/2012; 23(1):15-23. DOI:10.1016/j.wem.2011.12.008 · 1.49 Impact Factor
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ABSTRACT: Background: Arterial hemoglobin oxygen saturation (SaO(2)) decreases at an altitude of >1,500 m. There are no reports on normal SaO(2) at altitudes between 0 and 1,500 m. The clinical significance of decreased SaO(2) at such altitudes is unclear. Objective: To test the hypothesis that in healthy volunteers normal SaO(2) at moderate altitude (MA; 725 m) is lower than that at almost sea level (SL; 43 m). Methods: SaO(2) was measured by transcutaneous pulse oximetry in young healthy volunteers at MA and was compared to equivalent measurements at SL. In addition, a 6-min walk test was performed and SaO(2) at the end of the walk was compared between the two locations. Results: 111 males were checked at MA and 101 at SL. At rest, nadir SaO(2) was 95% at MA compared to 97% at SL. Mean SaO(2) at rest was slightly higher at SL (98.53 ± 0.52) compared to MA (98.11 ± 0.8; p < 0.01). In subjects who completed the 6-min walk test, SaO(2) slightly decreased after the test in both locations, by 0.38 ± 0.65% in the SL group and by 0.37 ± 1.12% in the MA group. This difference is not statistically significant by univariate analysis; however, a multiple regression analysis indicated that the drop in SaO(2) was higher at MA than at low altitude. Conclusions: We found a low but significant difference in SaO(2) between near-SL and at an altitude of 725 m. The clinical significance of this difference, in terms of human health, is probably minimal.Respiration 03/2012; 84(3):207-11. DOI:10.1159/000336554 · 2.92 Impact Factor