Intratest reliability and test–retest reproducibility of the oxygen uptake efficiency slope in healthy participants

2009 ◽  
Vol 16 (4) ◽  
pp. 493-498 ◽  
Author(s):  
Christophe Van Laethem ◽  
Johan De Sutter ◽  
Wim Peersman ◽  
Patrick Calders
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Minute Ventilation ◽  
Exercise Duration ◽  
Peak Oxygen Uptake ◽  
Exercise Tests ◽  
Uptake Efficiency ◽  
Carbon Dioxide Output ◽  
Oxygen Uptake Efficiency Slope ◽  
Healthy Participants

Background The oxygen uptake efficiency slope (OUES) is a newer ventilatory exercise parameter, used in the evaluation of healthy participants and patients with cardiovascular disease. However, few data about the reliability and reproducibility of OUES are available. Our study assessed intratest reliability and test-retest reproducibility of OUES in healthy participants. Design and methods Eighteen participants (age 28 ± 6 years, BMI 22.1 ± 1.9 kg/m2, 10 men) performed two identical maximal exercise tests on a bicycle ergometer. To assess test-retest reproducibility, we performed Bland-Altman analysis and calculated the coefficient of repeatability of the main ventilatory variables. Results OUES remained stable during the second part of the exercise test. Mean values varied 2.4 ± 4.0% between OUES calculated at 70% (OUES70) and at 100% of exercise duration. Mean variation decreased to 1.4 ± 2.3% when OUES was calculated at 90% of exercise duration (OUES90). The Bland-Altman 95% limits of agreement for OUES90 were +3 and –6%, those for OUES70 were +11 and –8%. The coefficient of repeatability for OUES was 597 ml/min or 18.7% of the average value of repeated OUES measurements. These results were similar to those of peak oxygen uptake and minute ventilation/carbon dioxide output. However, the test-retest reproducibility for submaximal-derived values of OUES was lower, as we noted higher coefficients of repeatability for OUES90 and OUES70, increasing up to 27% of the average of repeated values. Conclusion OUES shows excellent intratest reliability and has a test-retest reproducibility that is similar to that of peak oxygen uptake and minute ventilation/carbon dioxide output slope. However, its reproducibility becomes higher when it is calculated from increasing levels of achieved exercise intensity.

The Minute Ventilation/Carbon Dioxide Production Slope is Prognostically Superior to the Oxygen Uptake Efficiency Slope

2007 ◽  
Vol 13 (6) ◽  
pp. 462-469 ◽  
Author(s):  
Ross Arena ◽  
Jonathan Myers ◽  
Leon Hsu ◽  
Mary Ann Peberdy ◽  
Sherry Pinkstaff ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Minute Ventilation ◽  
Carbon Dioxide Production ◽  
Uptake Efficiency ◽  
Oxygen Uptake Efficiency Slope

Physiological responses and air consumption during simulated firefighting tasks in a subway system

2010 ◽  
Vol 35 (5) ◽  
pp. 671-678 ◽  
Author(s):  
F. Michael Williams-Bell ◽  
Geoff Boisseau ◽  
John McGill ◽  
Andrew Kostiuk ◽  
Richard L. Hughson
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Energy Requirement ◽  
Average Energy ◽  
Peak Oxygen Uptake ◽  
Search And Rescue ◽  
Moderate Intensity ◽  
Physiological Strain ◽  
Carbon Dioxide Output ◽  
Subway System

Professional firefighters (33 men, 3 women), ranging in age from 30 to 53 years, participated in a simulation of a subway system search and rescue while breathing from their self-contained breathing apparatus (SCBA). We tested the hypothesis that during this task, established by expert firefighters to be of moderate intensity, the rate of air consumption would exceed the capacity of a nominal 30-min cylinder. Oxygen uptake, carbon dioxide output, and air consumption were measured with a portable breath-by-breath gas exchange analysis system, which was fully integrated with the expired port of the SCBA. The task involved descending a flight of stairs, walking, performing a search and rescue, retreat walking, then ascending a single flight of stairs to a safe exit. This scenario required between 9:56 and 13:24 min:s (mean, 12:10 ± 1:10 min:s) to complete, with an average oxygen uptake of 24.3 ± 4.5 mL·kg–1·min–1 (47 ± 10 % peak oxygen uptake) and heart rate of 76% ± 7% of maximum. The highest energy requirement was during the final single-flight stair climb (30.4 ± 5.4 mL·kg–1·min–1). The average respiratory exchange ratio (carbon dioxide output/oxygen uptake) throughout the scenario was 0.95 ± 0.08, indicating a high carbon dioxide output for a relatively moderate average energy requirement. Air consumption from the nominal “30-min” cylinder averaged 51% (range, 26%–68%); however, extrapolation of these rates of consumption suggested that the low-air alarm, signalling that only 25% of the air remains, would have occurred as early as 11 min for an individual with the highest rate of air consumption, and at 16 min for the group average. These data suggest that even the moderate physical demands of walking combined with search and rescue while wearing full protective gear and breathing through the SCBA impose considerable physiological strain on professional firefighters. As well, the rate of air consumption in these tasks classed as moderate, compared with high-rise firefighting, would have depleted the air supply well before the nominal time used to describe the cylinders.

Evaluation of the Interchangeability of and Oxygen Uptake Efficiency Slope

2002 ◽  
Vol 27 (6) ◽  
pp. 589-601 ◽  
Author(s):  
Aurélien Pichon ◽  
Sophie Jonville ◽  
André Denjean
Keyword(s):  
Clinical Practice ◽  
Oxygen Uptake ◽  
Minute Ventilation ◽  
Limits Of Agreement ◽  
Uptake Efficiency ◽  
Interindividual Variations ◽  
Cardiorespiratory Function ◽  
The Difference ◽  
Two Parameters ◽  
Oxygen Uptake Efficiency Slope

A reliable submaximal test for assessing cardiorespiratory function would be of interest in clinical practice. Baba et al. (1996) proposed the oxygen uptake efficiency slope (OUES) derived from the relation between oxygen uptake ([Formula: see text] and minute ventilation [Formula: see text] during incremental exercise. We evaluated the validity of OUES by comparing maximal oxygen uptake [Formula: see text] predicted from OUES to measured [Formula: see text] in 50 healthy males who performed a maximal treadmill test. They had widely differing physical fitness levels ([Formula: see text]range, 32.7 to 80.2 mlO2 ∙ min−1 ∙ kg−1). Predicted [Formula: see text] was not significantly different (p > 0.99) from measured [Formula: see text] (56.8 ± 7.0 vs. 56.8 ± 8.8 mlO2 ∙ min−1 ∙ kg−1). The limits of agreement (Bland & Altman, 1986) were plus or minus 10.5 mlO2 ∙ min−1 ∙ kg−1. Although OUES and [Formula: see text]were significantly correlated (r = 0.79), the wide interindividual variations in the difference between these two parameters may limit the usefulness of OUES in clinical practice. Key Words: exercise, testing, OUES, fitness, agreement

Oxygen Uptake Efficiency Slope in Healthy Children

2010 ◽  
Vol 22 (3) ◽  
pp. 431-441 ◽  
Author(s):  
Moniek Akkerman ◽  
Marco van Brussel ◽  
Bart C. Bongers ◽  
Erik H.J. Hulzebos ◽  
Paul J.M Helders ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Ventilatory Threshold ◽  
Pediatric Population ◽  
Fat Free Mass ◽  
Healthy Children ◽  
Bicycle Ergometry ◽  
Exercise Tests ◽  
Uptake Efficiency ◽  
Cardiorespiratory Function ◽  
Oxygen Uptake Efficiency Slope

The objective of this study was to investigate the characteristics of the submaximal Oxygen Uptake Efficiency Slope (OUES) in a healthy pediatric population. Bicycle ergometry exercise tests with gas-analyses were performed in 46 healthy children aged 7–17 years. Maximal OUES, submaximal OUES, V̇O2peak, VEpeak, and ventilatory threshold (VT) were determined. The submaximal OUES correlated highly with V̇O2peak, VEpeak, and VT. Strong correlations were found with basic anthropometric variables. The submaximal OUES could provide an objective, independent measure of cardiorespiratory function in children, reflecting efficiency of ventilation. We recommend expressing OUES values relative to Body Surface Area (BSA) or Fat Free Mass (FFM).

scholarly journals Abnormalities of the Ventilatory Equivalent for Carbon Dioxide in Patients with Chronic Heart Failure

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Lee Ingle ◽  
Rebecca Sloan ◽  
Sean Carroll ◽  
Kevin Goode ◽  
John G. Cleland ◽  
...  
Keyword(s):  
Heart Failure ◽  
Carbon Dioxide ◽  
Chronic Heart Failure ◽  
Oxygen Uptake ◽  
Minute Ventilation ◽  
Carbon Dioxide Production ◽  
Peak Oxygen Uptake ◽  
Healthy Controls ◽  
Ventilatory Equivalent ◽  
All Cause Mortality

Introduction. The relation between minute ventilation (VE) and carbon dioxide production (VCO2) can be characterised by the instantaneous ratio of ventilation to carbon dioxide production, the ventilatory equivalent for CO2(VEqCO2). We hypothesised that the time taken to achieve the lowest VEqCO2(time to VEqCO2 nadir) may be a prognostic marker in patients with chronic heart failure (CHF).Methods. Patients and healthy controls underwent a symptom-limited, cardiopulmonary exercise test (CPET) on a treadmill to volitional exhaustion.Results. 423 patients with CHF (mean age years; 80% males) and 78 healthy controls (62% males; age years) were recruited. Time to VEqCO2 nadir was shorter in patients than controls ( s versus  s; ). Univariable predictors of all-cause mortality included peak oxygen uptake (), VEqCO2nadir (), and time to VEqCO2nadir (). In an adjusted Cox multivariable proportional hazards model, peak oxygen uptake () and VEqCO2nadir () were the most significant independent predictors of all-cause mortality.Conclusion. The time to VEqCO2nadir was shorter in patients with CHF than in normal subjects and was a predictor of subsequent mortality.

Validity of the Oxygen Uptake Efficiency Slope in Children With Cystic Fibrosis and Mild-To-Moderate Airflow Obstruction

2012 ◽  
Vol 24 (1) ◽  
pp. 129-141 ◽  
Author(s):  
Bart C. Bongers ◽  
Erik H.J. Hulzebos ◽  
Bert G.M. Arets ◽  
Tim Takken
Keyword(s):  
Cystic Fibrosis ◽  
Oxygen Uptake ◽  
Exercise Capacity ◽  
Ventilatory Threshold ◽  
Airflow Obstruction ◽  
Exercise Duration ◽  
Uptake Efficiency ◽  
Cardiopulmonary Exercise ◽  
Cardiopulmonary Exercise Capacity ◽  
Oxygen Uptake Efficiency Slope

Purpose: The oxygen uptake efficiency slope (OUES) has been proposed as an ‘effort-independent’ measure of cardiopulmonary exercise capacity, which could be used as an alternative measurement for peak oxygen uptake (VO2peak) in populations unable or unwilling to perform maximal exercise. The aim of the current study was to investigate the validity of the OUES in children with cystic fibrosis (CF). Methods: Exercise data of 22 children with CF and mild to moderate airflow obstruction were analyzed and compared with exercise data of 22 healthy children. The OUES was calculated using data up to three different relative exercise intensities, namely 50%, 75%, and 100% of the total exercise duration, and normalized for body surface area (BSA). Results: Only the OUES/BSA using the first 50% of the total exercise duration was significantly different between the groups. OUES/BSA values determined at different exercise intensities differed significantly within patients with CF and correlated only moderately with VO2peak and the ventilatory threshold. Conclusion: The OUES is not a valid submaximal measure of cardiopulmonary exercise capacity in children with mild to moderate CF, due to its limited distinguishing properties, its nonlinearity throughout progressive exercise, and its moderate correlation with VO2peak and the ventilatory threshold.

Carbon dioxide output

2021 ◽  
pp. 63-71
Author(s):  
William J.M. Kinnear ◽  
James H. Hull
Keyword(s):  
Carbon Dioxide ◽  
Lactic Acid ◽  
Oxygen Uptake ◽  
Dead Space ◽  
Exercise Test ◽  
Minute Ventilation ◽  
Cardiopulmonary Exercise Test ◽  
Carbon Dioxide Output ◽  
Cardiopulmonary Exercise ◽  
Ventilatory Equivalent

This chapter describes how carbon dioxide is produced from metabolism and also from buffering of lactic acid. The volume of carbon dioxide exhaled (VCO2) is calculated from the concentration in exhaled gas and minute ventilation. If the lungs are less efficient than normal, with a high dead space, the amount of ventilation needed to achieve any given VCO2 is much higher. This index, known as the ventilatory equivalent for carbon dioxide, is an important prognostic marker. Early on in a cardiopulmonary exercise test (CPET), VCO2 is slightly less than the oxygen uptake (VO2). As exercise reaches its maximum, VCO2 increases more quickly when acidaemia starts to stimulate ventilation.

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