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A new equation to estimate temperature-corrected PaCO2 from PET CO2 during exercise in normoxia and hypoxia.

González Henríquez, J J; Losa-Reyna, J; Torres-Peralta, R; Rådegran, Göran LU ; Koskolou, M and Calbet, J A L (2015) In Scandinavian Journal of Medicine & Science in Sports 26(9). p.1045-1051
Abstract
End-tidal PCO2 (PET CO2 ) has been used to estimate arterial pressure CO2 (Pa CO2 ). However, the influence of blood temperature on the Pa CO2 has not been taken into account. Moreover, there is no equation validated to predict Pa CO2 during exercise in severe acute hypoxia. To develop a new equation to predict temperature-corrected Pa CO2 values during exercise in normoxia and severe acute hypoxia, 11 volunteers (21.2 ± 2.1 years) performed incremental exercise to exhaustion in normoxia (Nox, PI O2 : 143 mmHg) and hypoxia (Hyp, PI O2 : 73 mmHg), while arterial blood gases and temperature (ABT) were simultaneously measured together with end-tidal PCO2 (PET CO2 ). The Jones et al. equation tended to underestimate the temperature corrected... (More)
End-tidal PCO2 (PET CO2 ) has been used to estimate arterial pressure CO2 (Pa CO2 ). However, the influence of blood temperature on the Pa CO2 has not been taken into account. Moreover, there is no equation validated to predict Pa CO2 during exercise in severe acute hypoxia. To develop a new equation to predict temperature-corrected Pa CO2 values during exercise in normoxia and severe acute hypoxia, 11 volunteers (21.2 ± 2.1 years) performed incremental exercise to exhaustion in normoxia (Nox, PI O2 : 143 mmHg) and hypoxia (Hyp, PI O2 : 73 mmHg), while arterial blood gases and temperature (ABT) were simultaneously measured together with end-tidal PCO2 (PET CO2 ). The Jones et al. equation tended to underestimate the temperature corrected (tc) Pa CO2 during exercise in hypoxia, with greater deviation the lower the Pa CO2 tc (r = 0.39, P < 0.05). The new equation has been developed using a random-effects regression analysis model, which allows predicting Pa CO2 tc both in normoxia and hypoxia: Pa CO2 tc = 8.607 + 0.716 × PET CO2 [R(2) = 0.91; intercept SE = 1.022 (P < 0.001) and slope SE = 0.027 (P < 0.001)]. This equation may prove useful in noninvasive studies of brain hemodynamics, where an accurate estimation of Pa CO2 is needed to calculate the end-tidal-to-arterial PCO2 difference, which can be used as an index of pulmonary gas exchange efficiency. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Scandinavian Journal of Medicine & Science in Sports
volume
26
issue
9
pages
1045 - 1051
publisher
Wiley-Blackwell
external identifiers
  • pmid:26314285
  • scopus:84940880223
ISSN
1600-0838
DOI
10.1111/sms.12545
language
English
LU publication?
yes
id
ce0b0c7e-e4a6-4e73-968e-f193c2d9c42b (old id 8043871)
date added to LUP
2015-10-07 21:46:20
date last changed
2017-01-01 07:52:09
@article{ce0b0c7e-e4a6-4e73-968e-f193c2d9c42b,
  abstract     = {End-tidal PCO2 (PET CO2 ) has been used to estimate arterial pressure CO2 (Pa CO2 ). However, the influence of blood temperature on the Pa CO2 has not been taken into account. Moreover, there is no equation validated to predict Pa CO2 during exercise in severe acute hypoxia. To develop a new equation to predict temperature-corrected Pa CO2 values during exercise in normoxia and severe acute hypoxia, 11 volunteers (21.2 ± 2.1 years) performed incremental exercise to exhaustion in normoxia (Nox, PI O2 : 143 mmHg) and hypoxia (Hyp, PI O2 : 73 mmHg), while arterial blood gases and temperature (ABT) were simultaneously measured together with end-tidal PCO2 (PET CO2 ). The Jones et al. equation tended to underestimate the temperature corrected (tc) Pa CO2 during exercise in hypoxia, with greater deviation the lower the Pa CO2 tc (r = 0.39, P &lt; 0.05). The new equation has been developed using a random-effects regression analysis model, which allows predicting Pa CO2 tc both in normoxia and hypoxia: Pa CO2 tc = 8.607 + 0.716 × PET CO2 [R(2) = 0.91; intercept SE = 1.022 (P &lt; 0.001) and slope SE = 0.027 (P &lt; 0.001)]. This equation may prove useful in noninvasive studies of brain hemodynamics, where an accurate estimation of Pa CO2 is needed to calculate the end-tidal-to-arterial PCO2 difference, which can be used as an index of pulmonary gas exchange efficiency.},
  author       = {González Henríquez, J J and Losa-Reyna, J and Torres-Peralta, R and Rådegran, Göran and Koskolou, M and Calbet, J A L},
  issn         = {1600-0838},
  language     = {eng},
  month        = {08},
  number       = {9},
  pages        = {1045--1051},
  publisher    = {Wiley-Blackwell},
  series       = {Scandinavian Journal of Medicine & Science in Sports},
  title        = {A new equation to estimate temperature-corrected PaCO2 from PET CO2 during exercise in normoxia and hypoxia.},
  url          = {http://dx.doi.org/10.1111/sms.12545},
  volume       = {26},
  year         = {2015},
}