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PubMed · 9451571

The inspiratory to end-tidal oxygen difference during exercise.

J Bengtsson·J P Bengtson
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Abstract

OBJECTIVE: Fast paramagnetic oxygen analyzers have made it possible to measure inspiratory to end-tidal oxygen concentration difference (P(I-ET)O2) breath-by-breath. It is now frequently displayed on monitors during routine anesthesia. We wanted to study the effects of major changes in metabolism, ventilation and circulation on P(I-ET)O2. METHODS: Ten healthy male volunteers were studied under exercise. P(I-ET)O2 was measured with a fast-response paramagnetic differential oxygen sensor. Cardiac output was measured with non-invasive transthoracic electrical bioimpedance. Metabolism was measured with indirect calorimetry and ventilation with a side stream spirometer. After a rest period, the subjects cycled at 30 W and 60 W, 6 minutes on each work load and were then observed during 10 minutes of rest. RESULTS: P(I-ET)O2 corresponded well to VO2/VA (the oxygen uptake to alveolar ventilation quotient) correlation showed r = 0.79. P(I-ET)O2 was influenced by changes in cardiac output which occurred primarily at the start and at the end of exercise. Expired minute ventilation (VE) multiplied by P(I-ET)O2 was related to cardiac output with a high intrapersonal correlation. CONCLUSION: P(I-ET)O2 is a good measure of adequate ventilation in relation to the oxygen consumption level and multiplied by VE it might offer a non-invasive bedside parameter indicating changes in cardiac output.

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AdultCardiac OutputElectron Spin Resonance SpectroscopyExerciseHumansMaleMathematical ComputingMiddle AgedOxygenOxygen ConsumptionPoint-of-Care SystemsPulmonary VentilationTidal VolumeJournal ArticleResearch Support, Non-U.S. Gov't

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J Bengtsson, J P Bengtson. 1997. The inspiratory to end-tidal oxygen difference during exercise.. https://doi.org/10.1007/bf03356566

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