Impact of periodic breathing on measurement of oxygen uptake and respiratory exchange ratio during cardiopulmonary exercise testing

2002 ◽  
Vol 103 (6) ◽  
pp. 543-552 ◽  
Author(s):  
Darrel P. FRANCIS ◽  
L. Ceri DAVIES ◽  
Keith WILLSON ◽  
Roland WENSEL ◽  
Piotr PONIKOWSKI ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Exercise Testing ◽  
Respiratory Exchange Ratio ◽  
Cardiopulmonary Exercise Testing ◽  
Periodic Breathing ◽  
Moving Window ◽  
Carbon Dioxide Output ◽  
Cardiopulmonary Exercise ◽  
Peak Vo2 ◽  
The Difference

Metabolic exercise testing is valuable in patients with chronic heart failure (CHF), but periodic breathing may confound the measurements. We aimed to examine the effects of periodic breathing on the measurement of oxygen uptake (VO2) and respiratory exchange ratio (RER). First, we measured the effects of different averaging procedures on peak VO2 and RER values in 122 patients with CHF undergoing cardiopulmonary exercise testing. Secondly, we studied the effects of periodic breathing on VO2 and RER in healthy volunteers performing computer-guided periodic breathing. Thirdly, we used a Fourier analysis to study the effects of periodic breathing on gas exchange measurements. The first part of the study showed that 1min moving window gave a mean peak VO2 of 13.8mlμmin-1μkg-1 for the CHF patients. A 15s window gave significantly higher values. The difference averaged 1.0mlμmin-1μkg-1 (P<0.0001), but varied widely: 41% of subjects showed a difference greater than 1.0mlμmin-1μkg-1. RER values were also higher by an average of 0.09 (P<0.0001); in 20% of subjects the difference was greater than 0.10. In the second part of the study, we found artefactual elevations of peak VO2 (without averaging) of 2.9mlμmin-1μkg-1 (P<0.01) and of peak RER of 0.13 (P<0.001), which were still significant when 30s averaging was applied [Δ(peak VO2) = 1.8mlμmin-1μkg-1, P<0.01; ΔRER = 0.08, P<0.001]. The third, theoretical, part of the study showed that values of carbon dioxide output and VO2 oscillate with different phases and amplitudes, resulting in oscillations in their ratio, RER. Averaging over 15s or 30s can be expected to give only 10% or 36% attenuation respectively. Thus periodic breathing causes variable artefactual elevations of measured peak VO2 and RER, which can be attenuated by using longer averaging periods. Clinical reports and research publications describing peak VO2 in CHF should be accompanied by details of the averaging technique used.

PETCO2 gradient: a novel prognostic parameter in cardiopulmonary exercise testing

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
I.D Poveda Pinedo ◽  
I Marco Clement ◽  
O Gonzalez ◽  
I Ponz ◽  
A.M Iniesta ◽  
...  
Keyword(s):  
Exercise Testing ◽  
Proportional Hazards ◽  
Cardiopulmonary Exercise Testing ◽  
Cox Proportional Hazards ◽  
Prognostic Parameter ◽  
Cardiopulmonary Exercise ◽  
Proportional Hazards Regression ◽  
Kaplan Meier ◽  
Baseline Characteristics ◽  
The Difference

Abstract Background Previous parameters such as peak VO2, VE/VCO2 slope and OUES have been described to be prognostic in heart failure (HF). The aim of this study was to identify further prognostic factors of cardiopulmonary exercise testing (CPET) in HF patients. Methods A retrospective analysis of HF patients who underwent CPET from January to November 2019 in a single centre was performed. PETCO2 gradient was defined by the difference between final PETCO2 and baseline PETCO2. HF events were defined as decompensated HF requiring hospital admission or IV diuretics, or decompensated HF resulting in death. Results A total of 64 HF patients were assessed by CPET, HF events occurred in 8 (12.5%) patients. Baseline characteristics are shown in table 1. Patients having HF events had a negative PETCO2 gradient while patients not having events showed a positive PETCO2 gradient (−1.5 [IQR −4.8, 2.3] vs 3 [IQR 1, 5] mmHg; p=0.004). A multivariate Cox proportional-hazards regression analysis revealed that PETCO2 gradient was an independent predictor of HF events (HR 0.74, 95% CI [0.61–0.89]; p=0.002). Kaplan-Meier curves showed a significantly higher incidence of HF events in patients having negative gradients, p=0.002 (figure 1). Conclusion PETCO2 gradient was demonstrated to be a prognostic parameter of CPET in HF patients in our study. Patients having negative gradients had worse outcomes by having more HF events. Time to first event, decompensated heart Funding Acknowledgement Type of funding source: None

Cardiopulmonary Exercise Testing in Combined Pulmonary Fibrosis and Emphysema

Respiration ◽  
2021 ◽  
pp. 369-377
Author(s):  
Michael Westhoff ◽  
Patric Litterst ◽  
Ralf Ewert
Keyword(s):  
Body Weight ◽  
Pulmonary Fibrosis ◽  
Sensitivity And Specificity ◽  
Exercise Testing ◽  
Cardiopulmonary Exercise Testing ◽  
Arterial Oxygen ◽  
Peak Exercise ◽  
Cutoff Value ◽  
Cardiopulmonary Exercise ◽  
Peak Vo2

Background: Combined pulmonary fibrosis and emphysema (CPFE) is a distinct entity among fibrosing lung diseases with a high risk for lung cancer and pulmonary hypertension (PH). Notably, concomitant PH was identified as a negative prognostic indicator that could help with early diagnosis to provide important information regarding prognosis. Objectives: The current study aimed to determine whether cardiopulmonary exercise testing (CPET) can be helpful in differentiating patients having CPFE with and without PH. Methods: Patients diagnosed with CPFE in 2 German cities (Hemer and Greifswald) over a period of 10 years were included herein. CPET parameters, such as peak oxygen uptake (peak VO2), functional dead space ventilation (VDf/VT), alveolar-arterial oxygen difference (AaDO2), arterial-end-tidal CO2 difference [P(a-ET)CO2] at peak exercise, and the minute ventilation-carbon dioxide production relationship (VE/VCO2 slope), were compared between patients with and without PH. Results: A total of 41 patients with CPET (22 with PH, 19 without PH) were analyzed. Right heart catheterization was performed in 15 of 41 patients without clinically relevant complications. Significant differences in peak VO2 (861 ± 190 vs. 1,397 ± 439 mL), VO2/kg body weight/min (10.8 ± 2.6 vs. 17.4 ± 5.2 mL), peak AaDO2 (72.3 ± 7.3 vs. 46.3 ± 14.2 mm Hg), VE/VCO2 slope (70.1 ± 31.5 vs. 39.6 ± 9.6), and peak P(a-ET)tCO2 (13.9 ± 3.5 vs. 8.1 ± 3.6 mm Hg) were observed between patients with and without PH (p < 0.001). Patients with PH had significantly higher VDf/VT at rest, VT1, and at peak exercise (65.6 ± 16.8% vs. 47.2 ± 11.6%; p < 0.001) than those without PH. A cutoff value of 44 for VE/VCO2 slope had a sensitivity and specificity of 94.7 and 72.7%, while a cutoff value of 11 mm Hg for P(a-ET)CO2 in combination with peak AaDO2 >60 mm Hg had a specificity and sensitivity of 95.5 and 84.2%, respectively. Combining peak AaDO2 >60 mm Hg with peak VO2/body weight/min <16.5 mL/kg/min provided a sensitivity and specificity of 100 and 95.5%, respectively. Conclusion: This study provided initial data on CPET among patients having CPFE with and without PH. CPET can help noninvasively detect PH and identify patients at risk. AaDO2 at peak exercise, VE/VCO2 slope, peak P(a-ET)CO2, and peak VO2 were parameters that had high sensitivity and, when combined, high specificity.

scholarly journals Can wearable technology be used to approximate cardiopulmonary exercise testing metrics?

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Laura Jones ◽  
Laura Tan ◽  
Suzanne Carey-Jones ◽  
Nathan Riddell ◽  
Richard Davies ◽  
...  
Keyword(s):  
Physical Activity ◽  
High Risk ◽  
Oxygen Uptake ◽  
Anaerobic Threshold ◽  
Exercise Testing ◽  
Low Cost ◽  
Cardiopulmonary Exercise Testing ◽  
Peak Oxygen Uptake ◽  
Wearable Device ◽  
Cardiopulmonary Exercise

Abstract Background Consumer wrist-worn wearable activity monitors are widely available, low cost and are able to provide a direct measurement of several markers of physical activity. Despite this, there is limited data on their use in perioperative risk prediction. We explored whether these wearables could accurately approximate metrics (anaerobic threshold, peak oxygen uptake and peak work) derived using formalised cardiopulmonary exercise testing (CPET) in patients undergoing high-risk surgery. Methods Patients scheduled for major elective intra-abdominal surgery and undergoing CPET were included. Physical activity levels were estimated through direct measures (step count, floors climbed and total distance travelled) obtained through continuous wear of a wrist worn activity monitor (Garmin Vivosmart HR+) for 7 days prior to surgery and self-report through completion of the short International Physical Activity Questionnaire (IPAQ). Correlations and receiver operating characteristic (ROC) curve analysis explored the relationships between parameters provided by CPET and physical activity. Device selection Our choice of consumer wearable device was made to maximise feasibility outcomes for this study. The Garmin Vivosmart HR+ had the longest battery life and best waterproof characteristics of the available low-cost devices. Results Of 55 patients invited to participate, 49 (mean age 65.3 ± 13.6 years; 32 males) were enrolled; 37 provided complete wearable data for analyses and 36 patients provided full IPAQ data. Floors climbed, total steps and total travelled as measured by the wearable device all showed moderate correlation with CPET parameters of peak oxygen uptake (peak VO2) (R = 0.57 (CI 0.29–0.76), R = 0.59 (CI 0.31–0.77) and R = 0.62 (CI 0.35–0.79) respectively), anaerobic threshold (R = 0.37 (CI 0.01–0.64), R = 0.39 (CI 0.04–0.66) and R = 0.42 (CI 0.07–0.68) respectively) and peak work (R = 0.56 (CI 0.27–0.75), R = 0.48 (CI 0.17–0.70) and R = 0.50 (CI 0.2–0.72) respectively). Receiver operator curve (ROC) analysis for direct and self-reported measures of 7-day physical activity could accurately approximate the ventilatory equivalent for carbon dioxide (VE/VCO2) and the anaerobic threshold. The area under these curves was 0.89 for VE/VCO2 and 0.91 for the anaerobic threshold. For peak VO2 and peak work, models fitted using just the wearable data were 0.93 for peak VO2 and 1.00 for peak work. Conclusions Data recorded by the wearable device was able to consistently approximate CPET results, both with and without the addition of patient reported activity measures via IPAQ scores. This highlights the potential utility of wearable devices in formal assessment of physical functioning and suggests they could play a larger role in pre-operative risk assessment. Ethics This study entitled “uSing wearable TEchnology to Predict perioperative high-riSk patient outcomes (STEPS)” gained favourable ethical opinion on 24 January 2017 from the Welsh Research Ethics Committee 3 reference number 17/WA/0006. It was registered on ClinicalTrials.gov with identifier NCT03328039.

Sign in / Sign up

Export Citation Format

Share Document