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Time courses for pulmonary oxygen uptake and cardiovascular responses are similar during apnea in resting humans

Andersson, Johan P.A. LU orcid ; Bacanovic, Tim LU ; Chen, Philip LU ; Lodin-Sundström, Angelica LU orcid ; Halder, Amitava LU orcid ; Persson, Gustav LU ; Linér, Mats H. LU and Sjögreen, Bodil LU (2025) In Frontiers in Physiology 16. p.1-12
Abstract

Introduction: The pulmonary oxygen uptake is reduced during apnea, compared to eupneic baseline, preserving the pulmonary oxygen store. This study elucidates the time course for this reduction, comparing it to the time course for apnea-induced cardiovascular responses. Methods and results: Experiments involved two groups, performing apneas during rest, both without and with cold-water face immersion (A and AFI). The first group (n = 18) performed A and AFI of gradually increasing durations (from 15 to 120 s, order unknown to participant), allowing analysis of the time course for apneic pulmonary gas exchange. The second group (n = 18) performed A and AFI of identical durations (mean: 137 s), allowing analysis of cardiovascular and... (More)

Introduction: The pulmonary oxygen uptake is reduced during apnea, compared to eupneic baseline, preserving the pulmonary oxygen store. This study elucidates the time course for this reduction, comparing it to the time course for apnea-induced cardiovascular responses. Methods and results: Experiments involved two groups, performing apneas during rest, both without and with cold-water face immersion (A and AFI). The first group (n = 18) performed A and AFI of gradually increasing durations (from 15 to 120 s, order unknown to participant), allowing analysis of the time course for apneic pulmonary gas exchange. The second group (n = 18) performed A and AFI of identical durations (mean: 137 s), allowing analysis of cardiovascular and respiratory responses. The time course for pulmonary oxygen uptake was similar to the time courses for heart rate and cardiac output, i.e., following a brief increase from eupneic baseline during the initial 15 s of A and AFI, the oxygen uptake was gradually reduced during apnea, reaching a sub-eupneic level from 30 s of apnea and onwards. Changes were augmented during AFI compared to A. Observations confirmed that cardiovascular responses to apnea, including a reduced cardiac output, reduced peripheral blood flow, and most likely a peripheralization of blood volume, preserved the pulmonary oxygen store, while the peripheral venous oxygen stores were depleted to a greater extent. Conclusions: We conclude that the central, pulmonary oxygen store is preserved with augmented cardiovascular responses to apnea, at the expense of peripheral venous oxygen stores, with a time course similar to that of the cardiovascular responses.

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author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
apnea, diving response, face immersion, hypercapnia, hypoxia, oxygen saturation, pulmonary gas exchange
in
Frontiers in Physiology
volume
16
article number
1524237
pages
1 - 12
publisher
Frontiers Media S. A.
external identifiers
  • pmid:40182688
  • scopus:105001677450
ISSN
1664-042X
DOI
10.3389/fphys.2025.1524237
project
Fysiologiska svar på apné och återandning, och betydelsen av olika initierande faktorer och kemoreceptorkänslighet
language
English
LU publication?
yes
additional info
Publisher Copyright: Copyright © 2025 Andersson, Bacanovic, Chen, Lodin-Sundström, Halder, Persson, Linér and Sjögreen.
id
36644980-93a7-4e3f-a26f-6b22206d0e8f
date added to LUP
2025-04-10 22:01:34
date last changed
2025-07-04 04:54:42
@article{36644980-93a7-4e3f-a26f-6b22206d0e8f,
  abstract     = {{<p>Introduction: The pulmonary oxygen uptake is reduced during apnea, compared to eupneic baseline, preserving the pulmonary oxygen store. This study elucidates the time course for this reduction, comparing it to the time course for apnea-induced cardiovascular responses. Methods and results: Experiments involved two groups, performing apneas during rest, both without and with cold-water face immersion (A and AFI). The first group (n = 18) performed A and AFI of gradually increasing durations (from 15 to 120 s, order unknown to participant), allowing analysis of the time course for apneic pulmonary gas exchange. The second group (n = 18) performed A and AFI of identical durations (mean: 137 s), allowing analysis of cardiovascular and respiratory responses. The time course for pulmonary oxygen uptake was similar to the time courses for heart rate and cardiac output, i.e., following a brief increase from eupneic baseline during the initial 15 s of A and AFI, the oxygen uptake was gradually reduced during apnea, reaching a sub-eupneic level from 30 s of apnea and onwards. Changes were augmented during AFI compared to A. Observations confirmed that cardiovascular responses to apnea, including a reduced cardiac output, reduced peripheral blood flow, and most likely a peripheralization of blood volume, preserved the pulmonary oxygen store, while the peripheral venous oxygen stores were depleted to a greater extent. Conclusions: We conclude that the central, pulmonary oxygen store is preserved with augmented cardiovascular responses to apnea, at the expense of peripheral venous oxygen stores, with a time course similar to that of the cardiovascular responses.</p>}},
  author       = {{Andersson, Johan P.A. and Bacanovic, Tim and Chen, Philip and Lodin-Sundström, Angelica and Halder, Amitava and Persson, Gustav and Linér, Mats H. and Sjögreen, Bodil}},
  issn         = {{1664-042X}},
  keywords     = {{apnea; diving response; face immersion; hypercapnia; hypoxia; oxygen saturation; pulmonary gas exchange}},
  language     = {{eng}},
  pages        = {{1--12}},
  publisher    = {{Frontiers Media S. A.}},
  series       = {{Frontiers in Physiology}},
  title        = {{Time courses for pulmonary oxygen uptake and cardiovascular responses are similar during apnea in resting humans}},
  url          = {{http://dx.doi.org/10.3389/fphys.2025.1524237}},
  doi          = {{10.3389/fphys.2025.1524237}},
  volume       = {{16}},
  year         = {{2025}},
}