End-tidal partial pressure of CO2 and minute ventilation: new measures to distinguish elite long-distance runners

2019 ◽  
Vol 22 ◽  
pp. S31
Author(s):  
A. Sakamoto ◽  
C. Chow ◽  
H. Naito
Keyword(s):  
Partial Pressure ◽  
Minute Ventilation ◽  
Distance Runners ◽  
Long Distance ◽  
Partial Pressure Of Co2 ◽  
End Tidal

Ventilatory and occlusion pressure responses to helium breathing

1983 ◽  
Vol 54 (6) ◽  
pp. 1525-1531 ◽  
Author(s):  
E. L. DeWeese ◽  
T. Y. Sullivan ◽  
P. L. Yu
Keyword(s):  
Breathing Circuit ◽  
Minute Ventilation ◽  
Normal Subjects ◽  
Mouth Pressure ◽  
Partial Pressure Of Co2 ◽  
Lung Resistance ◽  
Balloon Technique ◽  
Resistive Loads ◽  
End Tidal ◽  
Airway Tone

To characterize the ventilatory response to resistive unloading, we studied the effect of breathing 79.1% helium-20.9% oxygen (He-O2) on ventilation and on mouth pressure measured during the first 100 ms of an occluded inspiration (P100) in normal subjects at rest. The breathing circuit was designed so that external resistive loads during both He-O2 and air breathing were similar. Lung resistance, measured in three subjects with an esophageal balloon technique, was reduced by 23 +/- 8% when breathing He-O2. Minute ventilation, tidal volume, respiratory frequency, end-tidal partial pressure of CO2, inspiratory and expiratory durations, and mean inspiratory flow were not significantly different when air was replaced by He-O2. P100, however, was significantly less during He-O2 breathing. We conclude that internal resistive unloading by He-O2 breathing reduces the neuromuscular output required to maintain constant ventilation. Unlike studies involving inhaled bronchodilators, this technique affords a method by which unloading can be examined independent of changes in airway tone.

Control of ventilation in climbers to extreme altitude

1982 ◽  
Vol 53 (4) ◽  
pp. 886-890 ◽  
Author(s):  
R. B. Schoene
Keyword(s):  
Ventilatory Response ◽  
Distance Runners ◽  
Long Distance ◽  
Response Parameter ◽  
Extreme Altitude ◽  
Progressive Hypoxia ◽  
High Altitude Natives ◽  
End Tidal ◽  
Adequate Oxygenation ◽  
Ventilatory Response To Hypoxia

Blunted chemosensitivity has been found in successful endurance athletes and some high-altitude natives. This characteristic, however, may not be beneficial to climbers at extreme altitude, where a vigorous ventilatory response to hypoxia may be of value in enhancing alveolar and arterial oxygenation. We studied 14 climbers who had climbed to 7,470 m or higher, 10 age-matched controls, and 10 outstanding middle- and long-distance runners. The ventilatory response to progressive hypoxia was determined at a constant, normal end-tidal Pco2 over 8–12 min and to CO2 by rebreathing a 7% CO2 hyperoxic mixture (Read technique). The hypoxic response parameter of Weil, A was used to determine the hypoxic responses and S (delta VE/ delta PACO2) the hypercapnic response. Climbers had A values significantly higher than the runners (means +/- SE: 158.9 +/- 29.9 vs. 49.3 +/- 7.1, P less than 0.001) but not significantly higher than the controls (109.9 +/- 21.0). delta VE/ delta PACO2 of climbers was higher (3.0 +/- 0.4) than both controls (2.2 +/- 0.2, P less than 0.025) and runners (1.4 +/- 0.2, P less than 0.0005). These data suggest that successful climbers to extreme altitude may be selected by virtue of their vigorous respiratory responses to hypoxia to maintain adequate oxygenation in the presence of extreme environmental hypoxia.

Relationship between arterial oxygen desaturation and ventilation during maximal exercise

1992 ◽  
Vol 73 (6) ◽  
pp. 2588-2591 ◽  
Author(s):  
M. Miyachi ◽  
I. Tabata
Keyword(s):  
Maximal Exercise ◽  
Arterial Oxygen ◽  
Distance Runners ◽  
Long Distance ◽  
Positive Correlation ◽  
Ventilatory Equivalent ◽  
Wide Range ◽  
Highly Correlated ◽  
End Tidal ◽  
Arterial O2 Saturation

The purpose of the present study was to investigate the contribution of ventilation to arterial O2 desaturation during maximal exercise. Nine untrained subjects and 22 trained long-distance runners [age 18–36 yr, maximal O2 uptake (VO2max) 48–74 ml.min-1 x kg-1] volunteered to participate in the study. The subjects performed an incremental exhaustive cycle ergometry test at 70 rpm of pedaling frequency, during which arterial O2 saturation (SaO2) and ventilatory data were collected every minute. SaO2 was estimated with a pulse oximeter. A significant positive correlation was found between SaO2 and end-tidal PO2 (PETO2; r = 0.72, r2 = 0.52, P < 0.001) during maximal exercise. These statistical results suggest that approximately 50% of the variability of SaO2 can be accounted for by differences in PETO2, which reflects alveolar PO2. Furthermore, PETO2 was highly correlated with the ventilatory equivalent for O2 (VE/VO2; r = 0.91, P < 0.001), which indicates that PETO2 could be the result of ventilation stimulated by maximal exercise. Finally, SaO2 was positively related to VE/VO2 during maximal exercise (r = 0.74, r2 = 0.55, P < 0.001). Therefore, one-half of the arterial O2 desaturation occurring during maximal exercise may be explained by less hyperventilation, specifically for our subjects, who demonstrated a wide range of trained states. Furthermore, we found an indirect positive correlation between SaO2 and ventilatory response to CO2 at rest (r = 0.45, P < 0.05), which was mediated by ventilation during maximal exercise. These data also suggest that ventilation is an important factor for arterial O2 desaturation during maximal exercise.

scholarly journals Ventilatory parameters measured during a physiological study of simulated powered air-purifying respirator failure in healthy volunteers

2021 ◽  
pp. 0310057X2097898
Author(s):  
Lachlan F Miles ◽  
Timothy Makar ◽  
Chad W Oughton ◽  
Philip J Peyton
Keyword(s):  
Carbon Dioxide ◽  
Partial Pressure ◽  
Healthy Volunteers ◽  
Minute Ventilation ◽  
Peripheral Oxygen Saturation ◽  
Thermal Discomfort ◽  
Fraction Of Inspired Oxygen ◽  
Mechanical Devices ◽  
End Tidal ◽  
High Level

Powered air-purifying respirators (PAPR) are a high level of respiratory personal protective equipment. Like all mechanical devices, they are vulnerable to failure. The precise physiological consequences of failure in live subjects have not previously been reported. We conducted an observational safety study simulating PAPR failure in a group of nine healthy volunteers, wearing loose-fitting hoods, who were observed for a period of ten minutes, or until they requested the experiment be aborted, with continuous monitoring of gas exchange. Relative to baseline, participants demonstrated median reductions in peripheral oxygen saturation of 3.5% (95% confidence interval (CI) –4% to –2%; P = 0.0039) and fraction of inspired oxygen of 0.045 (95% CI –0.05 to –0.04; P = 0.0039), and median increases in inspired partial pressure of carbon dioxide of 27 mmHg (95% CI 23.5–32 mmHg; P = 0.0039), end-tidal partial pressure of carbon dioxide of 11 mmHg (95% CI 7–16 mmHg; P = 0.0039) and minute ventilation of 30 l/min (95% CI 19.4–35.9 l/min; P = 0.0039). Median collateral entrainment of room air into the hood was 17.6 l/min (interquartile range 12.3–27.0 l/min). All subjects reported thermal discomfort, with two (22.2%) requesting early termination of the experiment. Whilst the degree of rebreathing in this experiment was not sufficient to cause dangerous physiological derangement, the degree of reported thermal discomfort combined with the consequences of entrainment of possibly contaminated air into the hood, pose a risk to wearers in the event of failure.

scholarly journals Recent Insights into the Measurement of Carbon Dioxide Concentrations for Clinical Practice in Respiratory Medicine

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5636
Author(s):  
Akira Umeda ◽  
Masahiro Ishizaka ◽  
Akane Ikeda ◽  
Kazuya Miyagawa ◽  
Atsumi Mochida ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Clinical Practice ◽  
Partial Pressure ◽  
Sleep Apnea Syndrome ◽  
The Body ◽  
Non Invasive ◽  
Arterial Blood ◽  
Co2 Concentrations ◽  
Partial Pressure Of Co2 ◽  
End Tidal

In the field of respiratory clinical practice, the importance of measuring carbon dioxide (CO2) concentrations cannot be overemphasized. Within the body, assessment of the arterial partial pressure of CO2 (PaCO2) has been the gold standard for many decades. Non-invasive assessments are usually predicated on the measurement of CO2 concentrations in the air, usually using an infrared analyzer, and these data are clearly important regarding climate changes as well as regulations of air quality in buildings to ascertain adequate ventilation. Measurements of CO2 production with oxygen consumption yield important indices such as the respiratory quotient and estimates of energy expenditure, which may be used for further investigation in the various fields of metabolism, obesity, sleep disorders, and lifestyle-related issues. Measures of PaCO2 are nowadays performed using the Severinghaus electrode in arterial blood or in arterialized capillary blood, while the same electrode system has been modified to enable relatively accurate non-invasive monitoring of the transcutaneous partial pressure of CO2 (PtcCO2). PtcCO2 monitoring during sleep can be helpful for evaluating sleep apnea syndrome, particularly in children. End-tidal PCO2 is inferior to PtcCO2 as far as accuracy, but it provides breath-by-breath estimates of respiratory gas exchange, while PtcCO2 reflects temporal trends in alveolar ventilation. The frequency of monitoring end-tidal PCO2 has markedly increased in light of its multiple applications (e.g., verify endotracheal intubation, anesthesia or mechanical ventilation, exercise testing, respiratory patterning during sleep, etc.).

scholarly journals EXPRESS: PeakPETCO2 combined with FEV1/FVC predicts vasodilator-responsive patients with idiopathic pulmonary arterial hypertension

2021 ◽  
pp. 204589402110597
Author(s):  
cijun Luo ◽  
Hong-Ling Qiu ◽  
Chang-wei Wu ◽  
Jing He ◽  
Ping Yuan ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Pulmonary Function ◽  
Partial Pressure ◽  
Minute Ventilation ◽  
Cardiopulmonary Exercise Testing ◽  
Prediction Rule ◽  
Pulmonary Artery Hypertension ◽  
Heart Catheterization ◽  
Hemodynamic Effects ◽  
End Tidal

Background: Cardiopulmonary exercise testing (CPET) and pulmonary function test (PFT) are important methods for detecting human cardio-pulmonary function. Whether they could screen vasoresponsiveness in idiopathic pulmonary artery hypertension (IPAH) patients remains undefined. Methods: One hundred thirty-two IPAH patients with complete data were retrospectively enrolled. Patients were classified as vasodilator-responsive (VR) group and vasodilator-nonresponsive (VNR) group on the basis of the acute vasodilator test. PFT and CPET were assessed subsequently and all patients were confirmed by right heart catheterization. We analyzed CPET and PFT data and derived a prediction rule to screen vasodilator-responsive patients in IPAH. Results: Nineteen of VR-IPAH and 113 of VNR-IPAH patients were retrospectively enrolled. Compared with VNR-IPAH patients, VR-IPAH patients had less severe hemodynamic effects (lower RAP, m PAP, PAWP and PVR). And VR-IPAH patients had higher anaerobic threshold (AT), peak partial pressure of end-tidal carbon dioxide (PETCO2), oxygen uptake efficiency (OUEP) and FEV1/FVC (P all < 0.05), while lower peak partial pressure of end-tidal oxygen (PETO2) and minute ventilation (VE)/carbon dioxide output (VCO2) slope (P all < 0.05). FEV1/FVC (Odds Ratio [OR]: 1.14, 95% confidence interval [CI]: 1.02-1.26, P = 0.02) and PeakPETCO2 (OR: 1.13, 95% CI: 1.01-1.26, P = 0.04) were independent predictors of VR adjusted for age, sex and body mass index. A novel formula (= -16.17 + 0.123 × PeakPETCO2 + 0.127×FEV1/FVC) reached a high area under the curve value of 0.8 (P = 0.003). Combined with these parameters, the optimal cutoff value of this model for detection of VR is -1.06, with a specificity of 91% and sensitivity of 67%. Conclusions: Compared with VNR-IPAH patients, VR-IPAH patients had less severe hemodynamic effects. Higher FEV1/FVC and higher peak PETCO2 were associated with increased odds for vasoresponsiveness. A novel score combining Peak PETCO2 and FEV1/FVC provides high specificity to predict VR patients among IPAH.

scholarly journals Effects of Interval Training-Based Glycolytic Capacity on Physical Fitness in Recreational Long-Distance Runners

2015 ◽  
Vol 16 (2) ◽  
Author(s):  
Marek Zatoń ◽  
Kamil Michalik
Keyword(s):  
Physical Fitness ◽  
Minute Ventilation ◽  
Training Session ◽  
Interval Training ◽  
Control Group ◽  
Distance Runners ◽  
Continuous Training ◽  
Long Distance ◽  
Running Training ◽  
Experimental Group

AbstractPurpose. The aim of this study was to investigate the influence of 8-week-long interval training (targeting glycolytic capacity) on selected markers of physical fitness in amateur long-distance runners. Methods. The study involved 17 amateur long-distance runners randomly divided into an experimental (n = 8) and control (n = 9) group. The control group performed three or four continuous training sessions per week whereas the experimental group performed two interval running training sessions and one continuous running training session. A graded treadmill exercise test and the 12-min Cooper test were performed pre- and post-training. Results. O2max and the rate of recovery increased in the experimental group. Relative oxygen uptake, minute ventilation, and heart rate speed decreased in low- (6 km/h) and medium-intensity (12 km/h) running. Conclusions. Both training modalities showed similar results. However, the significant differences in training volume (4-8 min interval training vs. 40-150 min continuous training) indicates that the modalities targeting glycolytic capacity may be more efficient for amateur runners prepare for long-distance events.

Hypoxémie et Temps Limite à la Vitesse Aérobie Maximale Chez des Coureurs de Fond

1995 ◽  
Vol 20 (1) ◽  
pp. 102-111 ◽  
Author(s):  
Veronique Billat ◽  
Jean-Cyril Renoux ◽  
Jacques Pinoteau ◽  
Bernard Petit ◽  
Jean-Pierre Koralsztein
Keyword(s):  
Partial Pressure ◽  
Great Variability ◽  
Time To Exhaustion ◽  
Partial Pressure Of Oxygen ◽  
Distance Runners ◽  
Long Distance ◽  
Oxyhemoglobin Saturation ◽  
Arterial Partial Pressure ◽  
Maximal Aerobic Speed ◽  
Exercise Induced

A recent paper (Billat et al., 1994a) has shown the reproducibility but also the great variability between subelite long-distance runners in their time to exhaustion at the velocity which elicits [Formula: see text], called the maximal aerobic speed (MAS). The present study delved further into the reasons for this large difference between runners having the same [Formula: see text]. The question addressed was whether the exercise-induced hypoxemia (EIH) was more important for athletes having the longest time to exhaustion at 90 (Tlim 90), 100 (Tlim 100), or 105% (Tlim 105) of MAS. The study was conducted on 16 elite male runners. EIH was observed, that is, arteriel oxyhemoglobin saturation and arterial partial pressure of oxygen dropped significantly after all the Tlim tests. However, EIH was only correlated with Tlim 90 (r = −0.757; −0.531, respectively). Key words: exercise, running

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