D. S. Martin (1, 2), J. S. Pate (1, 3), A. Vercueil (1, 4), P. W. Doyle (1, 5), M. G. Mythen (1), M. P. W. Grocott (1, 6, 7), for the Caudwell Xtreme Everest Research Group
(1) UCL Centre for Altitude, Space and Extreme Environment Medicine, Portex Unit, Institute of Child Health, London, UK; (2) University College London, Division of Surgery and Interventional Science, Royal Free Hospital, London, UK; (3) Centre for Health and Human Performance, London, UK; (4) King's College Hospital, Denmark Hill, London, UK; (5) Anaesthetic Department, Charing Cross Hospital, Fulham Palace Road, London, UK; (6) Integrative Physiology Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Sir Henry Wellcome Laboratories, University Hospital Southampton NHS Foundation Trust, Southampton, UK; (7) Critical Care Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, UK
The impact of hypoxaemia on blood coagulation remains unclear despite use of a variety of measures to address the issue. We report the first use of thromboelastography (TEG) at high altitude to describe the dynamics of clot formation in whole blood samples. Seventeen healthy volunteers ascended to 5,300 m following an identical ascent profile; TEG measurements at 4,250 m and 5,300 m were compared with those from sea level. Peripheral oxygen saturation (SpO2) and haematocrit were also measured. Ascent resulted in a decline in SpO2 from 97.8 (± 1.2) % at sea level to 86.9 (± 3.3) % at 4,250 m and 79.5 (± 5.8) % at 5,300 m (p<0.001); haematocrit rose from 43.7 (± 2.8) % at sea level, to 46.7 (± 3.9) % and 52.6 (± 3.2) % at 4,250 m and 5,300 m, respectively (p<0.01). TEG reaction (R)-time and kinetic (K)-time were both increased at 5,300 m compared to sea level, 8.95 (± 1.37) minutes (min) to 11.69 (± 2.91) min (p=0.016) and 2.40 (± 0.66) min to 4.99 (± 1.67) min (p<0.001), respectively. Additionally the alpha (α)- angle was decreased from 57.7 (± 8.2) to 51.6 (± 6.4) (p<0.001). There was no change in maximum amplitude (MA) on ascent to altitude. These changes are consistent with an overall pattern of slowed coagulation at high altitude.
Hypoxia, blood coagulation, Blood, thrombelastography, coagulation tests, Altitude
Michael A. Bukys1, Tivadar Orban1, Paul Y. Kim2, Michael E. Nesheim2,3, Michael Kalafatis1,4
Thromb Haemost 2008 99 3: 511-522
Sandip M. Kanse1, Mariana Parahuleva2, Lars Muhl1, Bettina Kemkes-Matthes3, Daniel Sedding2, Klaus T. Preissner1
Thromb Haemost 2008 99 2: 286-289
T. Lang1,2, M. von Depka2
Hämostaseologie 2006 26 6: 21-29
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