On the breath-to-breath estimation of gas exchange

Swanson, George D.; Sherrill, D. L.

doi:10.1152/jappl.1984.56.1.259

Cited by 9 publications

(7 citation statements)

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“…At variance with previous similar studies, almost all of which have used cycle-ergometer exercise (Beaver et al, 1981;Capelli et al, 2001;Cettolo & Francescato, 2015;Swanson, 1980), in the present work the gas exchange calculation algorithms under investigation were applied on traces collected from subjects running at different speeds, up to very intense exercise.…”

Section: Strengths and Limitationsmentioning

confidence: 99%

“…The different calculation algorithms have usually been compared at rest or when limiting the exercise to the moderate-intensity domain (Auchincloss et al, 1966;Beaver, Lamarra, & Wasserman, 1981;Busso & Robbins, 1997;Capelli, Cautero, & di Prampero, 2001;Cautero, di Prampero, & Capelli, 2003;Grønlund, 1984;Swanson, 1980;Wessel et al, 1979;Wüst, Aliverti, Capelli, & Kayser, 2008); in a limited number of studies, volunteers reached oxygen uptakes as high as ∼3.5 l min −1 (Gimenez & Busso, 2008;Hughson, Northey, Xing, Dietrich, & Cochrane, 1991;Koga et al, 1989;Wilmore & Costill, 1973). A cycle-ergometer exercise protocol was adopted to evaluate the outcomes of the 'independent breath' algorithm (Francescato & Cettolo, 2019), in agreement with the majority of comparisons among gas exchange calculation algorithms (Beaver et al, 1981;Beaver, Wasserman, & Whipp, 1973;Capelli et al, 2001;Cautero et al, 2003;di Prampero & Lafortuna, 1989;Gimenez & Busso, 2008;Hughson et al, 1991;Koga et al, 1989;Swanson, 1980;Wüst et al, 2008). Limb movements and breathing, however, might not be isolated actions (Stickford & Stickford, 2014).…”

Section: Introductionmentioning

confidence: 99%

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Breath‐by‐breath oxygen uptake during running: Effects of different calculation algorithms

Koschate

Cettolo

Hoffmann

et al. 2019

Experimental Physiology

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New Findings What is the central question of this study?Breath‐by‐breath gas exchange analysis during treadmill exercise can be disturbed by different breathing patterns depending on cadence, and the flow sensor might be subjected to variable mechanical stress. It is still unclear whether the outcomes of the gas exchange algorithms can be affected by running at different speeds. What is the main finding and its importance?Practically, the three investigated breath‐by‐breath algorithms (‘Wessel’, ‘expiration‐only’ and ‘independent breath’) provided similar average gas exchange values for steady‐state conditions. The ‘independent breath’ algorithm showed the lowest breath‐by‐breath fluctuations in the gas exchange data compared with the other investigated algorithms, both at steady state and during incremental exercise. Abstract Recently, a new breath‐by‐breath gas exchange calculation algorithm (called ‘independent breath’) was proposed. In the present work, we aimed to compare the breath‐by‐breath O2 uptake (V̇normalO2) values assessed in healthy subjects undergoing a running protocol, as calculated applying the ‘independent breath’ algorithm or two other commonly used algorithms. The traces of respiratory flow, O2 and CO2 fractions, used by the calculation algorithms, were acquired at the mouth on 17 volunteers at rest, during running on a treadmill at 6.5 and 9.5 km h−1, and thereafter up to volitional fatigue. Within‐subject averages and standard deviations of breath‐by‐breath V̇normalO2 were calculated for steady‐state conditions; the V̇normalO2 data of the incremental phase were analysed by means of linear regression, and their root mean square was assumed to be an index of the breath‐by‐breath fluctuations. The average values obtained with the different algorithms were significantly different (P < 0.001); nevertheless, from a practical point of view the difference could be considered ‘small’ in all the investigated conditions (effect size <0.3). The standard deviations were significantly lower for the ‘independent breath’ algorithm (post hoc contrasts, P < 0.001), and the slopes of the relationships with the corresponding data yielded by the other algorithms were <0.70. The root mean squares of the linear regressions calculated for the incremental phase were also significantly lower for the ‘independent breath’ algorithm, and the slopes of the regression lines with the corresponding values obtained with the other algorithms were <0.84. In conclusion, the ‘independent breath’ algorithm yielded the least breath‐by‐breath O2 uptake fluctuation, both during steady‐state exercise and during incremental running.

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Section: Strengths and Limitationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Breath‐by‐breath oxygen uptake during running: Effects of different calculation algorithms

Koschate

Cettolo

Hoffmann

et al. 2019

Experimental Physiology

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“…First, many physiological studies that calculate O 2 consumption on a breath-by-breath basis use sophisticated corrections for nitrogen balance between inspired and expired gas and also estimate changes in lung volume within one breath; the Zeus Ò system does not use the same methods to calculate patient O 2 consumption. Second, physiological methods rigorously eliminate any leaks in the system (e.g., the volunteers breathe through tight mouthpieces and wear noseclips) while in clinical practice leaks are inevitable and indeed included in the Zeus Ò estimate of 'consumption' [14,15]. Further studies on this topic are obviously required, but one may speculate that very low flow anaesthesia cannot be safely achieved without feedback control on the patient's O 2 consumption.…”

Section: Discussionmentioning

confidence: 99%

Assessing the clinical or pharmaco‐economical benefit of target controlled desflurane delivery in surgical patients using the Zeus^® anaesthesia machine*

et al. 2009

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SummaryThe Zeus Ò anaesthesia machine includes an auto-control mode which allows targeting of end-tidal volatile and inspired oxygen concentrations. We assessed the clinical benefits and economic impact of this target-controlled anaesthesia compared with conventional manually controlled anaesthesia. Eighty patients were randomly assigned to receive desflurane either with a fresh gas flow set by the anaesthetist or in auto-control mode. Drug delivery was adjusted to maintain bispectral index between 40-60 units and systolic arterial pressure under 15 mmHg above its pre-induction value (upper limit) and over 90 mmHg (lower limit). Blood pressure was maintained in the desired range for 89% and 91% of the maintenance period for auto-control and manual control respectively (p = 0.49). Bispectral index was in the desired range for 82% and 79% of the maintenance period, for auto-control and manual control respectively (p = 0.46). Oxygen consumption was more than halved by the use of auto-control mode, and mean (SD) desflurane consumption during surgery was 0.07 (0.04) vs 0.2 (0.07) ml.min

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“…Respiratory volumes, flow and gas concentrations were recorded in real-time and used to build a profile of each breath. Alveolar gas exchange was calculated on a breath-by-breath basis using the algorithms of Swanson (1980).…”

Section: Data Collectionmentioning

confidence: 99%

The influence of metabolic and circulatory heterogeneity on the expression of pulmonary oxygen uptake kinetics in humans

Keir

Robertson

Benson

et al. 2015

Experimental Physiology

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On the breath-to-breath estimation of gas exchange

Cited by 9 publications

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Breath‐by‐breath oxygen uptake during running: Effects of different calculation algorithms

Breath‐by‐breath oxygen uptake during running: Effects of different calculation algorithms

Assessing the clinical or pharmaco‐economical benefit of target controlled desflurane delivery in surgical patients using the Zeus^® anaesthesia machine*

The influence of metabolic and circulatory heterogeneity on the expression of pulmonary oxygen uptake kinetics in humans

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On the breath-to-breath estimation of gas exchange

Cited by 9 publications

References 0 publications

Breath‐by‐breath oxygen uptake during running: Effects of different calculation algorithms

Breath‐by‐breath oxygen uptake during running: Effects of different calculation algorithms

Assessing the clinical or pharmaco‐economical benefit of target controlled desflurane delivery in surgical patients using the Zeus® anaesthesia machine*

The influence of metabolic and circulatory heterogeneity on the expression of pulmonary oxygen uptake kinetics in humans

Contact Info

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Assessing the clinical or pharmaco‐economical benefit of target controlled desflurane delivery in surgical patients using the Zeus^® anaesthesia machine*