The influence of P(a)O2, pH and S(a)O2 on maximal oxygen uptake

H. B. Nielsen; P. Madsen; L. B. Svendsen; R. C. Roach; N. H. Secher

doi:10.1046/j.1365-201X.1998.00405.x

The influence of P(a)O₂, pH and S(a)O₂ on maximal oxygen uptake

H. B. Nielsen^*, P. Madsen, L. B. Svendsen, R. C. Roach, N. H. Secher

^*Corresponding author for this work

71 Citations (Scopus)

Abstract

Influence of arterial oxygen pressure (P(a)O₂) and pH on haemoglobin saturation (S(a)O₂) and in turn on O₂ uptake (VO₂) was evaluated during ergometer rowing (156, 276 and 376 W; VO(2max) 5.0 L min^-1; n = 11). During low intensity exercise, neither pH nor S(a)O₂ were affected significantly. In response to the higher work intensities, ventilations (V(E)) of 129 ± 10 and 155 ± 8 L min^-1 enhanced the end tidal PO₂ (P(ET)O₂) to the same extent (117 ± 2 mmHg), but P(a)O₂ became reduced (from 102 ± 2 to 78 ± 2 and 81 ± 3 mmHg, respectively). As pH decreased during maximal exercise (7.14 ± 0.02 vs. 7.30 ± 0.02), S(a)O₂ also became lower (92.9 ± 0.7 vs. 95.1 + 0.1%) and arterial O₂ content (C(a)O₂) was 202 ± 3 mt L^-1. An inspired O₂ fraction (F(I)O₂) of 0.30 (n = 8) did not affect V(E), but increased P(ET)O₂ and P(aO)₂ to 175 ± 4 and 164 ± 5 mmHg and the P(ET)O₂-P(a)O₂ difference was reduced (21 ± 4 vs. 36 ± 4 mmHg). pH did not change when compared with normoxia and S(a)O₂ remained within 1% of the level at rest in hyperoxia (99 ± 0.1%). Thus, C(a)O₂ and VO(2max) increased to 212 ± 3 mL L^-1 and 5.7 ± 0.2 L min^-1, respectively. The reduced P(a)O₂ became of importance for S(a)O₂ when a low pH inhibited the affinity of O₂2 to haemoglobin. An increased F(I)O₂ reduced the gradient over the alveolar-arterial membrane, maintained haemoglobin saturation despite the reduction in pH and resulted in increases of the arterial oxygen content and uptake.

Original language	English
Journal	Acta Physiologica Scandinavica
Volume	164
Issue number	1
Pages (from-to)	89-97
Number of pages	9
ISSN	0001-6772
DOIs	https://doi.org/10.1046/j.1365-201X.1998.00405.x
Publication status	Published - 1998

Keywords

Arterial oxygen pressure
Arterial oxygen saturation
Hyperoxia
Lactate
pH
Rowing

Access to Document

10.1046/j.1365-201X.1998.00405.x

Cite this

@article{7e70bc680f4242259e3cce4dff58593d,

title = "The influence of P(a)O2, pH and S(a)O2 on maximal oxygen uptake",

abstract = "Influence of arterial oxygen pressure (P(a)O2) and pH on haemoglobin saturation (S(a)O2) and in turn on O2 uptake (VO2) was evaluated during ergometer rowing (156, 276 and 376 W; VO(2max) 5.0 L min-1; n = 11). During low intensity exercise, neither pH nor S(a)O2 were affected significantly. In response to the higher work intensities, ventilations (V(E)) of 129 ± 10 and 155 ± 8 L min-1 enhanced the end tidal PO2 (P(ET)O2) to the same extent (117 ± 2 mmHg), but P(a)O2 became reduced (from 102 ± 2 to 78 ± 2 and 81 ± 3 mmHg, respectively). As pH decreased during maximal exercise (7.14 ± 0.02 vs. 7.30 ± 0.02), S(a)O2 also became lower (92.9 ± 0.7 vs. 95.1 + 0.1%) and arterial O2 content (C(a)O2) was 202 ± 3 mt L-1. An inspired O2 fraction (F(I)O2) of 0.30 (n = 8) did not affect V(E), but increased P(ET)O2 and P(aO)2 to 175 ± 4 and 164 ± 5 mmHg and the P(ET)O2-P(a)O2 difference was reduced (21 ± 4 vs. 36 ± 4 mmHg). pH did not change when compared with normoxia and S(a)O2 remained within 1% of the level at rest in hyperoxia (99 ± 0.1%). Thus, C(a)O2 and VO(2max) increased to 212 ± 3 mL L-1 and 5.7 ± 0.2 L min-1, respectively. The reduced P(a)O2 became of importance for S(a)O2 when a low pH inhibited the affinity of O22 to haemoglobin. An increased F(I)O2 reduced the gradient over the alveolar-arterial membrane, maintained haemoglobin saturation despite the reduction in pH and resulted in increases of the arterial oxygen content and uptake.",

keywords = "Arterial oxygen pressure, Arterial oxygen saturation, Hyperoxia, Lactate, pH, Rowing",

author = "Nielsen, {H. B.} and P. Madsen and Svendsen, {L. B.} and Roach, {R. C.} and Secher, {N. H.}",

year = "1998",

doi = "10.1046/j.1365-201X.1998.00405.x",

language = "English",

volume = "164",

pages = "89--97",

journal = "Acta Physiologica Scandinavica",

issn = "0001-6772",

publisher = "Wiley-Blackwell Publishing Ltd",

number = "1",

}

TY - JOUR

T1 - The influence of P(a)O2, pH and S(a)O2 on maximal oxygen uptake

AU - Nielsen, H. B.

AU - Madsen, P.

AU - Svendsen, L. B.

AU - Roach, R. C.

AU - Secher, N. H.

PY - 1998

Y1 - 1998

N2 - Influence of arterial oxygen pressure (P(a)O2) and pH on haemoglobin saturation (S(a)O2) and in turn on O2 uptake (VO2) was evaluated during ergometer rowing (156, 276 and 376 W; VO(2max) 5.0 L min-1; n = 11). During low intensity exercise, neither pH nor S(a)O2 were affected significantly. In response to the higher work intensities, ventilations (V(E)) of 129 ± 10 and 155 ± 8 L min-1 enhanced the end tidal PO2 (P(ET)O2) to the same extent (117 ± 2 mmHg), but P(a)O2 became reduced (from 102 ± 2 to 78 ± 2 and 81 ± 3 mmHg, respectively). As pH decreased during maximal exercise (7.14 ± 0.02 vs. 7.30 ± 0.02), S(a)O2 also became lower (92.9 ± 0.7 vs. 95.1 + 0.1%) and arterial O2 content (C(a)O2) was 202 ± 3 mt L-1. An inspired O2 fraction (F(I)O2) of 0.30 (n = 8) did not affect V(E), but increased P(ET)O2 and P(aO)2 to 175 ± 4 and 164 ± 5 mmHg and the P(ET)O2-P(a)O2 difference was reduced (21 ± 4 vs. 36 ± 4 mmHg). pH did not change when compared with normoxia and S(a)O2 remained within 1% of the level at rest in hyperoxia (99 ± 0.1%). Thus, C(a)O2 and VO(2max) increased to 212 ± 3 mL L-1 and 5.7 ± 0.2 L min-1, respectively. The reduced P(a)O2 became of importance for S(a)O2 when a low pH inhibited the affinity of O22 to haemoglobin. An increased F(I)O2 reduced the gradient over the alveolar-arterial membrane, maintained haemoglobin saturation despite the reduction in pH and resulted in increases of the arterial oxygen content and uptake.

AB - Influence of arterial oxygen pressure (P(a)O2) and pH on haemoglobin saturation (S(a)O2) and in turn on O2 uptake (VO2) was evaluated during ergometer rowing (156, 276 and 376 W; VO(2max) 5.0 L min-1; n = 11). During low intensity exercise, neither pH nor S(a)O2 were affected significantly. In response to the higher work intensities, ventilations (V(E)) of 129 ± 10 and 155 ± 8 L min-1 enhanced the end tidal PO2 (P(ET)O2) to the same extent (117 ± 2 mmHg), but P(a)O2 became reduced (from 102 ± 2 to 78 ± 2 and 81 ± 3 mmHg, respectively). As pH decreased during maximal exercise (7.14 ± 0.02 vs. 7.30 ± 0.02), S(a)O2 also became lower (92.9 ± 0.7 vs. 95.1 + 0.1%) and arterial O2 content (C(a)O2) was 202 ± 3 mt L-1. An inspired O2 fraction (F(I)O2) of 0.30 (n = 8) did not affect V(E), but increased P(ET)O2 and P(aO)2 to 175 ± 4 and 164 ± 5 mmHg and the P(ET)O2-P(a)O2 difference was reduced (21 ± 4 vs. 36 ± 4 mmHg). pH did not change when compared with normoxia and S(a)O2 remained within 1% of the level at rest in hyperoxia (99 ± 0.1%). Thus, C(a)O2 and VO(2max) increased to 212 ± 3 mL L-1 and 5.7 ± 0.2 L min-1, respectively. The reduced P(a)O2 became of importance for S(a)O2 when a low pH inhibited the affinity of O22 to haemoglobin. An increased F(I)O2 reduced the gradient over the alveolar-arterial membrane, maintained haemoglobin saturation despite the reduction in pH and resulted in increases of the arterial oxygen content and uptake.

KW - Arterial oxygen pressure

KW - Arterial oxygen saturation

KW - Hyperoxia

KW - Lactate

KW - pH

KW - Rowing

UR - http://www.scopus.com/inward/record.url?scp=0032159179&partnerID=8YFLogxK

U2 - 10.1046/j.1365-201X.1998.00405.x

DO - 10.1046/j.1365-201X.1998.00405.x

M3 - Journal article

C2 - 9777029

AN - SCOPUS:0032159179

SN - 0001-6772

VL - 164

SP - 89

EP - 97

JO - Acta Physiologica Scandinavica

JF - Acta Physiologica Scandinavica

IS - 1

ER -

The influence of P(a)O₂, pH and S(a)O₂ on maximal oxygen uptake

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this