Dynamic of end-tidal carbon dioxide pressure during cardiopulmonary exercise testing before and after heart transplantation

Background: N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiopulmonary exercise testing (CPET) are useful for severity assessment in patients with pulmonary hypertension (PH). Correlations between these tests in pre-capillary PH patients is less well studied. Methods: We studied 23 patients with pre-capillary PH: 8 with idiopathic pulmonary arterial hypertension (IPAH), 6 with systemic sclerosis-associated PAH (SSc-PAH), and 9 with chronic thromboembolic pulmonary hypertension (CTEPH). Clinical evaluation, NT-proBNP levels, six-minute walking test (6MWT), spirometry, and CPET were evaluated on the same day. Correlation between NT-proBNP levels and CPET parameters were investigated. Results: In all patients, NT-proBNP levels were significantly correlated with peak oxygen uptake (VO2) ( r = −0.47), peak oxygen pulse ( r = −0.43), peak cardiac output (CO) ( r = −0.57), peak end-tidal partial pressure of carbon dioxide (PETCO2) ( r = −0.74), ventilatory equivalent to carbon dioxide (VE/VCO2) at anaerobic threshold (AT) ( r = 0.73), and VE/VCO2 slope ( r = 0.64). Significant correlations between NT-proBNP levels and peak PETCO2 and VE/VCO2 were found in IPAH and CTEPH subgroups, and a significant correlation between NT-proBNP levels and VO2 at AT was found in the CTEPH subgroup. No significant correlation was found in the SSc-PAH subgroup. Conclusion: NT-proBNP levels were significantly correlated with CPET parameters in patients with IPAH and CTEPH subgroups, but not in SSc-PAH subgroup. A further study with larger population is required to confirm these preliminary findings.

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Roles of periodic breathing and isocapnic buffering period during exercise in heart failure

European Journal of Preventive Cardiology ◽

10.1177/2047487320952029 ◽

2020 ◽

Vol 27 (2_suppl) ◽

pp. 19-26

Author(s):

Piergiuseppe Agostoni ◽

Michele Emdin ◽

Fabiana De Martino ◽

Anna Apostolo ◽

Marco Masè ◽

...

Keyword(s):

Heart Failure ◽

Prognostic Value ◽

Cardiopulmonary Exercise Testing ◽

Periodic Breathing ◽

Sympathetic Activation ◽

Cardiopulmonary Exercise ◽

End Tidal Carbon Dioxide ◽

Carbon Dioxide Pressure ◽

Exercise Induced ◽

End Tidal

In heart failure, exercise – induced periodic breathing and end tidal carbon dioxide pressure value during the isocapnic buffering period are two features identified at cardiopulmonary exercise testing strictly related to sympathetic activation. In the present review we analysed the physiology behind periodic breathing and the isocapnic buffering period and present the relevant prognostic value of both periodic breathing and the presence/absence of the identifiable isocapnic buffering period.

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Exercise end-tidal carbon dioxide pressure: a new prognostic marker after acute myocardial infarction?

European Journal of Preventive Cardiology ◽

10.1093/eurjpc/zwab061.091 ◽

2021 ◽

Vol 28 (Supplement_1) ◽

Author(s):

J Ferreira ◽

P Rio ◽

A Castelo ◽

I Cardoso ◽

S Silva ◽

...

Keyword(s):

Myocardial Infarction ◽

Carbon Dioxide ◽

Acute Myocardial Infarction ◽

Prognostic Marker ◽

Systolic Function ◽

Prognostic Role ◽

End Tidal Carbon Dioxide ◽

Carbon Dioxide Pressure ◽

End Tidal ◽

Maximal Effort

Abstract Funding Acknowledgements Type of funding sources: None. Background Although several cardiopulmonary exercise testing (CPET) parameters have already proved to predict prognosis, there is increasing interest in finding variables that do not require maximal effort. End-tidal carbon dioxide pressure (PETCO2), an indirect indicator of cardiac output, is one of such variables. Studies in heart failure populations already suggest its role as a prognostic factor. However, data concerning other populations are still scarce. Purpose To assess the association between exercise PETCO2, cardiac biomarkers and systolic function following acute myocardial infarction (AMI) and to evaluate its potential prognostic role in this population. Methods A retrospective single-centre analysis was conducted including patients who underwent symptom-limited CPET early after AMI. We assessed PETCO2 at baseline (PETCO2-B), at anaerobic threshold (PETCO2-AT) and at peak exercise and calculated the difference between PETCO2-AT and PETCO2-B (PETCO2-difference). We analysed their association with B-natriuretic peptide (BNP), maximal troponin after AMI as well as with left ventricular ejection fraction (LVEF) 1 year after. Results We included 40 patients with a mean age of 56 years (87.5% male), assessed with CPET a median of 3 months after AMI (80% of which were ST-elevation myocardial infarctions). Average respiratory exchange ratio was 1,1 with 48% of patients not reaching maximal effort. Mean PETCO2-AT was 37mmHg, with a mean increase from baseline of 6mmHg (PETCO2-difference). There was a significant positive correlation between all the PETCO2 variables measured and BNP values at time of AMI and on follow-up (best correlation for PETCO2-AT with BNP at AMI hospitalization, r = 0.608, p < 0.001). Maximal troponin was not correlated with PETCO2. Both PETCO2-AT and PETCO2-difference were significantly and positively correlated with LVEF 1-year post-AMI (r = 0.421, p = 0.040 and r = 0.511, p = 0.011, respectively). Conclusion PETCO2-AT and PETCO2-difference are both correlated with BNP, an established prognostic marker, and with medium-term systolic function after AMI, suggesting their potential prognostic role in this population. Further studies with larger samples are required to confirm the results of this pilot study and assess PETCO2 as a definite predictor of prognosis after AMI.

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Accuracy of Postoperative End-tidal Pco2Measurements with Mainstream and Sidestream Capnography in Non-obese Patients and in Obese Patients with and without Obstructive Sleep Apnea

Anesthesiology ◽

10.1097/aln.0b013e3181b060b6 ◽

2009 ◽

Vol 111 (3) ◽

pp. 609-615 ◽

Cited By ~ 49

Author(s):

Yusuke Kasuya ◽

Ozan Akça ◽

Daniel I. Sessler ◽

Makoto Ozaki ◽

Ryu Komatsu

Keyword(s):

Carbon Dioxide ◽

Body Mass Index ◽

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Nasal Cannula ◽

Obese Patients ◽

Obstructive Sleep ◽

End Tidal Carbon Dioxide ◽

Carbon Dioxide Pressure ◽

End Tidal

Background Obtaining accurate end-tidal carbon dioxide pressure measurements via nasal cannula poses difficulties in postanesthesia patients who are mouth breathers, including those who are obese and those with obstructive sleep apnea (OSA); a nasal cannula with an oral guide may improve measurement accuracy in these patients. The authors evaluated the accuracy of a mainstream capnometer with an oral guide nasal cannula and a sidestream capnometer with a nasal cannula that did or did not incorporate an oral guide in spontaneously breathing non-obese patients and obese patients with and without OSA during recovery from general anesthesia. Methods The study enrolled 20 non-obese patients (body mass index less than 30 kg/m) without OSA, 20 obese patients (body mass index greater than 35 kg/m) without OSA, and 20 obese patients with OSA. End-tidal carbon dioxide pressure was measured by using three capnometer/cannula combinations (oxygen at 4 l/min): (1) a mainstream capnometer with oral guide nasal cannula, (2) a sidestream capnometer with a nasal cannula that included an oral guide, and (3) a sidestream capnometer with a standard nasal cannula. Arterial carbon dioxide partial pressure was determined simultaneously. The major outcome was the arterial-to-end-tidal partial pressure difference with each combination. Results In non-obese patients, arterial-to-end-tidal pressure difference was 3.0 +/- 2.6 (mean +/- SD) mmHg with the mainstream capnometer, 4.9 +/- 2.3 mmHg with the sidestream capnometer and oral guide cannula, and 7.1 +/- 3.5 mmHg with the sidestream capnometer and a standard cannula (P < 0.05). In obese non-OSA patients, it was 3.9 +/- 2.6 mmHg, 6.4 +/- 3.1 mmHg, and 8.1 +/- 5.0 mmHg, respectively (P < 0.05). In obese OSA patients, it was 4.0 +/- 3.1 mmHg, 6.3 +/- 3.2 mmHg, and 8.3 +/- 4.6 mmHg, respectively (P < 0.05). Conclusions Mainstream capnometry performed best, and an oral guide improved the performance of sidestream capnometry. Accuracy in non-obese and obese patients, with and without OSA, was similar.

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Comparison of end-tidal carbon dioxide and point-of-care echocardiography for fluid response at the bedside

Hong Kong Journal of Emergency Medicine ◽

10.1177/1024907919870929 ◽

2019 ◽

pp. 102490791987092 ◽

Cited By ~ 1

Author(s):

Semih Korkut ◽

Erden Erol Ünlüer ◽

Arif Karagöz ◽

Karama Bouchaala Mnif ◽

Emine Kadioğlu

Keyword(s):

Carbon Dioxide ◽

Cardiac Output ◽

Point Of Care ◽

Passive Leg Raising ◽

Velocity Time Integral ◽

Time Integral ◽

End Tidal Carbon Dioxide ◽

Before And After ◽

End Tidal ◽

Bedside Method

Purpose: In this study, we aimed to compare cardiac output, echocardiographic pulmonary velocity-time integral, and end-tidal carbon dioxide values before and after the passive leg raising maneuver in healthy volunteers. Methods: The Ethical Commission approved the study. A total of 36 volunteers were included after signed informed consent in our study. After 12 h of fasting, vital signs, cardiac output, pulmonary velocity-time integral, and end-tidal carbon dioxide were measured when the participants were lying supine. Then, participants’ legs were elevated to 45° passively, and all measurements were repeated. Pulmonary velocity-time integral was obtained in parasternal short-axis view with the aid of pulse Doppler. Pulmonary root measurements were recorded. Echocardiographic stroke volume and cardiac output were calculated. The differences between values of cardiac output, pulmonary velocity-time integral, and end-tidal carbon dioxide before and after passive leg raising were statistically compared. The level of significance was accepted as p < 0.05. Results: Significant differences were found between pre- and post-passive leg raising values of these three measurements. The effect of passive leg raising on pulmonary velocity-time integral measurements was greater. The change in end-tidal carbon dioxide was not correlated with either cardiac output or pulmonary velocity-time integral alteration. Conclusion: Our results showed that measurement of pulmonary velocity-time integral changes after passive leg raising is a more useful bedside method to predict fluid responsiveness than measurement of end-tidal carbon dioxide and cardiac output alteration.

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End-tidal carbon dioxide pressure in neonates and infants measured by aspiration and flow-through capnography

Journal of Clinical Monitoring and Computing ◽

10.1007/bf01619346 ◽

1991 ◽

Vol 7 (4) ◽

pp. 285-288 ◽

Cited By ~ 15

Author(s):

J. Michael Badgwell ◽

James E. Heavner

Keyword(s):

Carbon Dioxide ◽

End Tidal Carbon Dioxide ◽

Carbon Dioxide Pressure ◽

Flow Through ◽

End Tidal ◽

Neonates And Infants

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North American Society for Pediatric Exercise Medicine

Pediatric Exercise Science ◽

10.1123/pes.20.3.s1 ◽

2008 ◽

Vol 20 (Suppl_3) ◽

pp. S1-S59

Author(s):

M.R. Johnson ◽

P. Hopkins-Price

Keyword(s):

Carbon Dioxide ◽

Pulmonary Function ◽

Exercise Testing ◽

Study Groups ◽

Cycle Ergometer ◽

The Body ◽

Maximal Heart Rate ◽

Exercise Tests ◽

End Tidal Carbon Dioxide ◽

End Tidal

Background:Children may undergo exercise testing for multiple reasons. Exercise testing measures multiple physiologic parameters when the body is under stress and can be performed by cycle or treadmill protocols. A higher oxygen consumption (VO2) has been noted by treadmill protocols. The oxygen uptake efficiency slope (OUES) and slope of ventilation to carbon dioxide (VE/VCO2) are newer parameters of cardiopulmonary response. Differences in OUES and VE/VCO2 slope have not been compared in regards to method of testing.Methods:Clinical exercise tests performed by graded treadmill (Treadmill group) were compared with those performed by cycle ergometer (Cycle controls) from a previous study carried out at a separate institution. Exercise testing of persons with cystic fibrosis (Cycle CF) was evaluated during the same study. Age, weight, height, body mass index, sex, pulmonary function, maximal heart rate, VO2max, VEmax, end tidal carbon dioxide (ET-CO2), OUES and VE/VCO2 slope were compared by unpaired student’s T-test among the three groups. Pearson product moment correlations compared VO2max, OUES and VE/VCO2 slope in all three study groups.Results:The Treadmill group and Cycle controls had similar age, height, weight, BMI and baseline pulmonary function. The Cycle CF group had lower height, weight and BMI but similar age and pulmonary function to the other two groups. VO2max, and VEmax were significantly higher in Treadmill group than cycle controls. OUES was higher in the Treadmill group than cycle controls (p=0.07). Correlation between VO2max and OUES was 0.89 in treadmill group, 0.96 in cycle controls and 0.93 in cycle CF.Discussion:This study suggests OUES and VO2max, are highly correlated in healthy controls whether obtained by cycle or treadmill protocols. Variation in the level of correlation between VE/VCO2 slope and VO2max existed in the three study populations. VE/VCO2 slope correlated highest with end tidal carbon dioxide at maximal exercise and this may confound the use of the VE/VCO2 slope in healthy populations. No clear advantage to testing by treadmill or cycle ergometry was determined in this study and testing can be determined based on institutional preference.

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Carbon dioxide elimination pattern at cardiopulmonary exercise testing in patients with low ejection fraction value

Russian Pulmonology ◽

10.18093/0869-0189-2019-29-6-647-653 ◽

2020 ◽

Vol 29 (6) ◽

pp. 647-653

Author(s):

O. V. Kamenskaya ◽

I. Yu. Loginova ◽

A. M. Chernyavskiy ◽

D. V. Doronin ◽

V. V. Lomivorotov

Keyword(s):

Carbon Dioxide ◽

Ejection Fraction ◽

Exercise Testing ◽

Resting State ◽

Cardiopulmonary Exercise Testing ◽

Unfavorable Outcome ◽

Cardiopulmonary Exercise ◽

Low Ejection Fraction ◽

Over Time

The objective of this study was to evaluate partial pressure of end tidal carbon dioxide (PetCO2) over time on exertion (E) and its predictive value in evaluation of risk of unfavorable outcome in patients with low ejection fraction (EF) value.Materials and Methods. Patients (n = 53) with pronounced chronic heart failure (CHF), included in heart transplantation waiting list, were enrolled in the prospective study. All patients underwent cardiopulmonary exercise testing (CPET). Mortality or INCOR left ventricle bypass system implantation according to vital indications within 1 year of follow-up were evaluated as an end-point.Results. Patients with CHF and low EF were characterized by low parameters of E tolerance and peak oxygen consumption (10.4 (9.6–11.7) ml/min/kg). The average PetCO2 level by group was 30.4 (28.3–33.0) mm Hg; in 32% of patients this value decreased or did not change in CPET compared with that in resting state. The significant relationship between increased risk of unfavorable outcome within 1 year of follow-up with low baseline PetCO2 value (odds ratio (OR) – 0.22 (0.05–0.87); p = 0.020) and absence of its increment in PE (OR – 0.16 (0.10–0.54); p = 0.009) was observed.Conclusion. The significant predictive factors of unfavorable outcome within 1 year of follow-up in patients with pronounced CHF and low EF include PetCO2 value in resting state, as well as PetCO2 change over time after E challenge.

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