Angus Sutherland1, Joseph Freer2, Laura Evans3, Alberto Dolci4, Matteo Crotti5, Jamie Hugo Macdonald6. 1. 1 Anaesthetic Department, Portsmouth Hospitals Trust, Queen Alexandra Hospital , Portsmouth, United Kingdom . 2. 2 The BMJ , BMA House, Tavistock Square, London, United Kingdom . 3. 3 Intensive Care Department, Northern General Hospital , Sheffield, United Kingdom . 4. 4 Faculty of Science and Technology, University of Westminster , London, United Kingdom . 5. 5 School of Exercise and Sports Sciences , Università degli Studi di Milano, Milan, Italy . 6. 6 Extremes Research Group, School of Sport, Health and Exercise Sciences, Bangor University , Bangor, United Kingdom .
Abstract
Sutherland, Angus, Joseph Freer, Laura Evans, Alberto Dolci, Matteo Crotti, and Jamie Hugo Macdonald. MEDEX 2015: Heart rate variability predicts development of acute mountain sickness. High Alt Med Biol. 18: 199-208, 2017. AIMS: Acute mountain sickness (AMS) develops when the body fails to acclimatize to atmospheric changes at altitude. Preascent prediction of susceptibility to AMS would be a useful tool to prevent subsequent harm. Changes to peripheral oxygen saturation (SpO2) on hypoxic exposure have previously been shown to be of poor predictive value. Heart rate variability (HRV) has shown promise in the early prediction of AMS, but its use pre-expedition has not previously been investigated. We aimed to determine whether pre- and intraexpedition HRV assessment could predict susceptibility to AMS at high altitude with better diagnostic accuracy than SpO2. METHODS: Forty-four healthy volunteers undertook an expedition in the Nepali Himalaya to >5000 m. SpO2 and HRV parameters were recorded at rest in normoxia and in a normobaric hypoxic chamber before the expedition. On the expedition HRV parameters and SpO2 were collected again at 3841 m. A daily Lake Louise Score was obtained to assess AMS symptomology. RESULTS: Low frequency/high frequency (LF/HF) ratio in normoxia (cutpoint ≤2.28 a.u.) and LF following 15 minutes of exposure to normobaric hypoxia had moderate (area under the curve ≥0.8) diagnostic accuracy. LF/HF ratio in normoxia had the highest sensitivity (85%) and specificity (88%) for predicting AMS on subsequent ascent to altitude. In contrast, pre-expedition SpO2 measurements had poor (area under the curve <0.7) diagnostic accuracy and inferior sensitivity and specificity. CONCLUSIONS: Pre-ascent measurement of HRV in normoxia was found to be of better diagnostic accuracy for AMS prediction than all measures of HRV in hypoxia, and better than peripheral oxygen saturation monitoring.
Sutherland, Angus, Joseph Freer, Laura Evans, Alberto Dolci, Matteo Crotti, and Jamie Hugo Macdonald. MEDEX 2015: Heart rate variability predicts development of acute mountain sickness. High Alt Med Biol. 18: 199-208, 2017. AIMS: Acute mountain sickness (AMS) develops when the body fails to acclimatize to atmospheric changes at altitude. Preascent prediction of susceptibility to AMS would be a useful tool to prevent subsequent harm. Changes to peripheral oxygen saturation (SpO2) on hypoxic exposure have previously been shown to be of poor predictive value. Heart rate variability (HRV) has shown promise in the early prediction of AMS, but its use pre-expedition has not previously been investigated. We aimed to determine whether pre- and intraexpedition HRV assessment could predict susceptibility to AMS at high altitude with better diagnostic accuracy than SpO2. METHODS: Forty-four healthy volunteers undertook an expedition in the Nepali Himalaya to >5000 m. SpO2 and HRV parameters were recorded at rest in normoxia and in a normobaric hypoxic chamber before the expedition. On the expedition HRV parameters and SpO2 were collected again at 3841 m. A daily Lake Louise Score was obtained to assess AMS symptomology. RESULTS: Low frequency/high frequency (LF/HF) ratio in normoxia (cutpoint ≤2.28 a.u.) and LF following 15 minutes of exposure to normobaric hypoxia had moderate (area under the curve ≥0.8) diagnostic accuracy. LF/HF ratio in normoxia had the highest sensitivity (85%) and specificity (88%) for predicting AMS on subsequent ascent to altitude. In contrast, pre-expedition SpO2 measurements had poor (area under the curve <0.7) diagnostic accuracy and inferior sensitivity and specificity. CONCLUSIONS: Pre-ascent measurement of HRV in normoxia was found to be of better diagnostic accuracy for AMS prediction than all measures of HRV in hypoxia, and better than peripheral oxygen saturation monitoring.
Authors: Tobias Kammerer; Valentina Faihs; Nikolai Hulde; Andreas Bayer; Max Hübner; Florian Brettner; Walter Karlen; Julia Maria Kröpfl; Markus Rehm; Christina Spengler; Simon Thomas Schäfer Journal: Ann Occup Environ Med Date: 2018-11-19
Authors: Christopher J Boos; Kyo Bye; Luke Sevier; Josh Bakker-Dyos; David R Woods; Mark Sullivan; Tom Quinlan; Adrian Mellor Journal: Front Physiol Date: 2018-04-16 Impact factor: 4.566