Evidence map›Paper›PMID 25501722›Full record

ArticleBritish journal of anaesthesia2015

Systemic oxygen extraction during exercise at high altitude.

D S Martin, A Cobb, P Meale, K Mitchell, M Edsell, M G Mythen, M P W Grocott, Xtreme Alps Research Group

Open access · bronzeAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in British journal of anaesthesia, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 11 papers.

0numbers the graph read from it
0cells of the map it votes in
11citing papers in PubMed
1.4field-weighted citation impact, top 16% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

11 citing papers in PubMed, 18 citations in OpenAlex.

  1. Trial
  2. Review
  3. Exercise performance reduction and preventive measures in highland sports.Zhong nan da xue xue bao. Yi xue ban = Journal of Central South University. Medical sciences · 2023
    Article
  4. Article
  5. Observational
  6. Observational
  7. Article
  8. Measurement of CMROJournal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism · 2020
    Article
  9. Article
  10. Article
  11. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors at 4 institutions in 1 country.

D S MartinUCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, University College London Centre for Altitude Space and Extreme Environment Medicine, 170 Tottenham Court Road, London W1 T 7HA, UK daniel.martin@ucl.ac.uk.
A CobbUCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, University College London Centre for Altitude Space and Extreme Environment Medicine, 170 Tottenham Court Road, London W1 T 7HA, UK.
P MealeUCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, University College London Centre for Altitude Space and Extreme Environment Medicine, 170 Tottenham Court Road, London W1 T 7HA, UK.
K MitchellUCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, University College London Centre for Altitude Space and Extreme Environment Medicine, 170 Tottenham Court Road, London W1 T 7HA, UK Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Mailpoint 810, Sir Henry Wellcome Laboratories, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton SO16 6YD, UK Anaesthesia and Critical Care Research Unit, GICU, Mailpoint 27, Level D, Centre Block, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton SO16 6YD, UK NIHR Southampton Respiratory Biomedical Research Unit, Southampton, UK.
M EdsellUCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, University College London Centre for Altitude Space and Extreme Environment Medicine, 170 Tottenham Court Road, London W1 T 7HA, UK Department of Anaesthesia, St George's Hospital, London, UK.
M G MythenUCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, University College London Centre for Altitude Space and Extreme Environment Medicine, 170 Tottenham Court Road, London W1 T 7HA, UK.
M P W GrocottUCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, University College London Centre for Altitude Space and Extreme Environment Medicine, 170 Tottenham Court Road, London W1 T 7HA, UK Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Mailpoint 810, Sir Henry Wellcome Laboratories, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton SO16 6YD, UK Anaesthesia and Critical Care Research Unit, GICU, Mailpoint 27, Level D, Centre Block, University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton SO16 6YD, UK NIHR Southampton Respiratory Biomedical Research Unit, Southampton, UK.
Xtreme Alps Research Group
University College London · GBSt George's Hospital · GBUniversity Hospital Southampton NHS Foundation Trust · GBUniversity of Southampton · GB

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundClassic teaching suggests that diminished availability of oxygen leads to increased tissue oxygen extraction yet evidence to support this notion in the context of hypoxaemia, as opposed to anaemia or cardiac failure, is limited.

methodsAt 75 m above sea level, and after 7-8 days of acclimatization to 4559 m, systemic oxygen extraction [C(a-v)O2] was calculated in five participants at rest and at peak exercise. Absolute [C(a-v)O2] was calculated by subtracting central venous oxygen content (CcvO2) from arterial oxygen content [Formula: see text] in blood sampled from central venous and peripheral arterial catheters, respectively. Oxygen uptake [Formula: see text] was determined from expired gas analysis during exercise.

resultsAscent to altitude resulted in significant hypoxaemia; median (range) [Formula: see text] 87.1 (82.5-90.7)% and [Formula: see text] 6.6 (5.7-6.8) kPa. While absolute C(a-v)O2 was reduced at maximum exercise at 4559 m [83.9 (67.5-120.9) ml litre(-1) vs 99.6 (88.0-151.3) ml litre(-1) at 75 m, P=0.043], there was no change in oxygen extraction ratio (OER) [C(a-v)O2/CaO2] between the two altitudes [0.52 (0.48-0.71) at 4559 m and 0.53 (0.49-0.73) at 75 m, P=0.500]. Comparison of C(a-v)O2 at peak [Formula: see text] at 4559 m and the equivalent [Formula: see text] at sea level for each participant also revealed no significant difference [83.9 (67.5-120.9) ml litre(1) vs 81.2 (73.0-120.7) ml litre(-1), respectively, P=0.225].

conclusionIn acclimatized individuals at 4559 m, there was a decline in maximum absolute C(a-v)O2 during exercise but no alteration in OER calculated using central venous oxygen measurements. This suggests that oxygen extraction may have become limited after exposure to 7-8 days of hypoxaemia.

Indexed as

AltitudeExerciseAcclimatizationAdultFemaleHumansMaleOxygenOxygen ConsumptionOxygenaltitudeblood gas analysisexercisehypoxiaoxygenphysiology

Identifiers

PMID25501722
PMCPMC4364061
OpenAlexW2143998609

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.