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The walking-induced transient hack concept is valid & relies on a transient early-exercise hypoxemia.

Bruneau A, Feuilloy M, Dussaussoy C, Gagnadoux F, Leftheriotis G, Abraham P - PLoS ONE (2013)

Bottom Line: Clustering classes were compared to the profile types previously proposed with the cross-correlation technique.The classifications of patients according to both approaches were compared using kappa statistics.Clustering analysis resulted in 4 classes that closely fit the 4 most frequently proposed empirical models (cross-correlation coefficients: 0.93 to 0.97).

View Article: PubMed Central - PubMed

Affiliation: L'Université Nantes Angers Le Mans, Centre Hospitalier Universitaire d'Angers, Laboratory for Vascular Investigations, Angers, France.

ABSTRACT

Background: Decreased arterial oxygen pressure obtained at peak exercise is strong evidence of walking-induced hypoxemia, assuming that the lower pressure occurs just before exercise is stopped. Using empirical predefined models and transcutaneous oximetry, we have shown that some patients reporting exercise intolerance show a minimal value at the onset of walking and a post-exercise overshoot. These changes are referred to as transcutaneous "walking-induced transient hacks".

Methods: In 245 patients, walking-induced transcutaneous oxygen pressure changes in the chest were analyzed using observer-independent clustering techniques. Clustering classes were compared to the profile types previously proposed with the cross-correlation technique. The classifications of patients according to both approaches were compared using kappa statistics. In 10 patients showing a hack on transcutaneous oximetry, we analyzed the results of direct iterative arterial sampling recorded during a new walking treadmill test.

Results: Clustering analysis resulted in 4 classes that closely fit the 4 most frequently proposed empirical models (cross-correlation coefficients: 0.93 to 0.97). The kappa between the two classifications was 0.865. In 10 patients showing transcutaneous hacks, the minimal direct arterial oxygen pressure value occurred at exercise onset, and these patients exhibited a recovery overshoot reaching a maximum at two minutes of recovery, confirming the walking-induced transient hypoxemia.

Conclusions: In patients reporting exercise intolerance, transcutaneous oximetry could help to detect walking-induced transient hypoxemia, while peak-exercise arterial oximetry might be normal.

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Related in: MedlinePlus

Simultaneous recording of chest transcutaneous and arterial oxygen pressure.Chest transcutaneous oxygen pressure (Transcutaneous pO2) and arterial pressure corrected for temperature changes (Art. temp.-corr. pO2). The dark square is the walking period.
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pone-0062651-g004: Simultaneous recording of chest transcutaneous and arterial oxygen pressure.Chest transcutaneous oxygen pressure (Transcutaneous pO2) and arterial pressure corrected for temperature changes (Art. temp.-corr. pO2). The dark square is the walking period.

Mentions: Typical results from a patient showing a chest transcutaneous pO2 hack are presented in figure 4, showing the initial decrease and abrupt post-exercise overshoot.


The walking-induced transient hack concept is valid & relies on a transient early-exercise hypoxemia.

Bruneau A, Feuilloy M, Dussaussoy C, Gagnadoux F, Leftheriotis G, Abraham P - PLoS ONE (2013)

Simultaneous recording of chest transcutaneous and arterial oxygen pressure.Chest transcutaneous oxygen pressure (Transcutaneous pO2) and arterial pressure corrected for temperature changes (Art. temp.-corr. pO2). The dark square is the walking period.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3643941&req=5

pone-0062651-g004: Simultaneous recording of chest transcutaneous and arterial oxygen pressure.Chest transcutaneous oxygen pressure (Transcutaneous pO2) and arterial pressure corrected for temperature changes (Art. temp.-corr. pO2). The dark square is the walking period.
Mentions: Typical results from a patient showing a chest transcutaneous pO2 hack are presented in figure 4, showing the initial decrease and abrupt post-exercise overshoot.

Bottom Line: Clustering classes were compared to the profile types previously proposed with the cross-correlation technique.The classifications of patients according to both approaches were compared using kappa statistics.Clustering analysis resulted in 4 classes that closely fit the 4 most frequently proposed empirical models (cross-correlation coefficients: 0.93 to 0.97).

View Article: PubMed Central - PubMed

Affiliation: L'Université Nantes Angers Le Mans, Centre Hospitalier Universitaire d'Angers, Laboratory for Vascular Investigations, Angers, France.

ABSTRACT

Background: Decreased arterial oxygen pressure obtained at peak exercise is strong evidence of walking-induced hypoxemia, assuming that the lower pressure occurs just before exercise is stopped. Using empirical predefined models and transcutaneous oximetry, we have shown that some patients reporting exercise intolerance show a minimal value at the onset of walking and a post-exercise overshoot. These changes are referred to as transcutaneous "walking-induced transient hacks".

Methods: In 245 patients, walking-induced transcutaneous oxygen pressure changes in the chest were analyzed using observer-independent clustering techniques. Clustering classes were compared to the profile types previously proposed with the cross-correlation technique. The classifications of patients according to both approaches were compared using kappa statistics. In 10 patients showing a hack on transcutaneous oximetry, we analyzed the results of direct iterative arterial sampling recorded during a new walking treadmill test.

Results: Clustering analysis resulted in 4 classes that closely fit the 4 most frequently proposed empirical models (cross-correlation coefficients: 0.93 to 0.97). The kappa between the two classifications was 0.865. In 10 patients showing transcutaneous hacks, the minimal direct arterial oxygen pressure value occurred at exercise onset, and these patients exhibited a recovery overshoot reaching a maximum at two minutes of recovery, confirming the walking-induced transient hypoxemia.

Conclusions: In patients reporting exercise intolerance, transcutaneous oximetry could help to detect walking-induced transient hypoxemia, while peak-exercise arterial oximetry might be normal.

Show MeSH
Related in: MedlinePlus