The Project
Research title
Expedition & year
Project funders
Aim of project
MEDEX 2015: Positional Changes in Arterial Oxygen Saturation at High Altitude
Medex Medical Expedition Manasalu 2015
Can sitting up instead of lying down improve the amount of oxygen in the blood
when at high altitude?
James D. Anholm, MD1
Project staff
Principal
Investigator
Collaborators
Arlena Kuenzel, MD2, Ben R Marshall, BSc MBBS3
Institutes involved 1VA Loma Linda Healthcare System, Loma Linda, California, USA 92357
2Redcliffe Hospital, Metro North Hospital and Health Service, Brisbane, Australia
3Sheffield Teaching Hospitals NHS Foundation Trust, UK
Hypothesis
What was the
idea for the
research?
Data
collection
What did your
participants have
to do?
Photos
What data did
you collect?
Attach 2 photos
of research in
action.
Body position alters many aspects of lung function. At sea level the amount we
breathe changes when standing upright compared to when lying down. Such
changes could be important for maintaining how much oxygen we get
into our blood at high altitude. It is unclear whether similar changes in body
position also change lung function at high altitude although anecdotal
observations from previous expeditions suggest that oxygen saturation in the
blood may be altered by changes in body position.
We hypothesized that following ascent to altitude, sitting upright would result in
higher oxygen saturation than when lying down.
Thirty-five healthy participants were studied at sea level. After gradual ascent to
about 5050m altitude 28 of these participants were again studied. The other 7
participants could not have repeat testing at altitude for a variety of reasons
including time constraints imposed by weather at altitude and illness. After 10
minutes of sitting rest, each subject had breathing and oxygen saturation
(SpO2) measured continuously for 5 minutes while lying down on their back,
another 5 minutes lying on the stomach and 5 minutes sitting. The order of the
positions was chosen at random for each subject.
Blood oxygen levels, carbon dioxide level at the end of a person’s breath, volume
of air breathed, heart rate,
Photo captions
The results
Sharing the
results
The future
Who took the
photos?
What did you find
out?
What are the
implications of
your findings (e.g.
for altitude
medicine)?
At what
conferences have
the findings been
presented?
What peer
reviewed papers
have been
published?
What books or
lay publications
have been
published?
What plans do
you have to use
Photo 1: Arlena and James monitoring subject at 5050m
Photo 2: Ben preparing subject to be studied at 5050m
Unknown
We observed small but significantly higher oxygen saturation and lower carbon
dioxide levels while sitting upright compared with lying down. These changes
occurred in most, but not all subjects for unclear reasons. At sea level there was
no change in oxygen saturation in different body positions. In conclusion, most
subjects following gradual ascent to high altitude have higher oxygen saturation
while sitting up compared to lying down.
The findings may have implications for the treatment advice given to people
suffering from altitude illness.
Oral presentation (abstract number 38), at the International Society for Mountain
Medicine, 7th World Congress on Wilderness and Mountain Medicine, Telluride,
CO (USA) (29.07.16):
http://online.liebertpub.com/doi/full/10.1089/ham.2016.29011.abstra
cts
Presented at Birmingham Medical Research Expeditionary Society Biannual
Meeting. 26 November 2016.
Presented at Hypoxia 2017. 7 – 12 February 2017.
In progress
Nil to date
The exact mechanisms accounting for these changes are currently being studied.
the data in the
future?
What do you
Additional study of how acclimatization affects positional oxygen saturation.
think should be
researched next?
Any other
Future high altitude studies should make a note of body position along with
comments /
oxygen levels
advice for others?