Augmented Hyperventilation Via Normoxic Helium Breathing Does Not Prevent Exercise-Induced Hypoxemia

1996 ◽  
Vol 21 (4) ◽  
pp. 264-270 ◽  
Author(s):  
Michael J. Buono ◽  
Richard Maly
Keyword(s):  
Oxygen Saturation ◽  
Maximal Exercise ◽  
Arterial Oxygen Saturation ◽  
Ambient Air ◽  
Cycle Ergometer ◽  
Endurance Athletes ◽  
Arterial Oxygen ◽  
Volitional Exhaustion ◽  
Graded Exercise ◽  
Exercise Induced

The purpose of this study was to determine if augmented hyperventilation produced via normoxic helium breathing would reduce exercise-induced hypoxemia (EIH). Seven highly trained endurance athletes with a mean maximum oxygen uptake of 65 ml∙kg−1∙min−1, performed two cycle ergometer tests to volitional exhaustion. During one of the tests the subjects breathed ambient air, while during the other they breathed normoxic helium (21% O2, 79% He). Mean maximum expired ventilation significantly (p <.05) increased from 139 L∙min−1 during the ambient trial to 168 L∙min−1 while breathing normoxic helium. Mean arterial oxygen saturation obtained at maximum exercise, however, was not significantly different for the two trials (ambient = 90%, helium = 89%). These results suggest that significantly augmenting exercise hyperventilation by 21% essentially had no effect on EIH in endurance athletes. Thus, the data do not support the hypothesis that inadequate hyperventilation is an important mechanism for arterial oxygen desaturation during graded exercise to exhaustion in highly trained individuals. Key words: arterial oxygen saturation, endurance athletes, maximal exercise

ARTERIAL OXYGEN SATURATION DURING GRADED EXERCISE TESTING AFTER CARDIAC TRANSPLANTATION. 11

1998 ◽  
Vol 18 (5) ◽  
pp. 348 ◽  
Author(s):  
Ray W. Squires ◽  
Craig J. Hoffman ◽  
Grace A. James ◽  
Nichole A. Schriever ◽  
Thomas G. Allison ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Exercise Testing ◽  
Cardiac Transplantation ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Graded Exercise Testing ◽  
Graded Exercise

Diving response and arterial oxygen saturation during apnea and exercise in breath-hold divers

2002 ◽  
Vol 93 (3) ◽  
pp. 882-886 ◽  
Author(s):  
Johan P. A. Andersson ◽  
Mats H. Linér ◽  
Elisabeth Rünow ◽  
Erika K. A. Schagatay
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Oxygen Saturation ◽  
Cold Water ◽  
Arterial Oxygen Saturation ◽  
Cycle Ergometer ◽  
Arterial Oxygen ◽  
Breath Hold ◽  
Diving Response ◽  
Face Immersion

This study addressed the effects of apnea in air and apnea with face immersion in cold water (10°C) on the diving response and arterial oxygen saturation during dynamic exercise. Eight trained breath-hold divers performed steady-state exercise on a cycle ergometer at 100 W. During exercise, each subject performed 30-s apneas in air and 30-s apneas with face immersion. The heart rate and arterial oxygen saturation decreased and blood pressure increased during the apneas. Compared with apneas in air, apneas with face immersion augmented the heart rate reduction from 21 to 33% ( P < 0.001) and the blood pressure increase from 34 to 42% ( P < 0.05). The reduction in arterial oxygen saturation from eupneic control was 6.8% during apneas in air and 5.2% during apneas with face immersion ( P < 0.05). The results indicate that augmentation of the diving response slows down the depletion of the lung oxygen store, possibly associated with a larger reduction in peripheral venous oxygen stores and increased anaerobiosis. This mechanism delays the fall in alveolar and arterial Po 2 and, thereby, the development of hypoxia in vital organs. Accordingly, we conclude that the human diving response has an oxygen-conserving effect during exercise.

Effects of incomplete pulmonary gas exchange on VO2 max

1989 ◽  
Vol 66 (6) ◽  
pp. 2491-2495 ◽  
Author(s):  
S. K. Powers ◽  
J. Lawler ◽  
J. A. Dempsey ◽  
S. Dodd ◽  
G. Landry
Keyword(s):  
Gas Exchange ◽  
Sea Level ◽  
Maximal Exercise ◽  
Cycle Ergometer ◽  
Pulmonary Gas Exchange ◽  
Endurance Athletes ◽  
Healthy Male ◽  
Exercise Tests ◽  
Ergometer Exercise ◽  
Exercise Induced

Recent evidence suggests that heavy exercise may lower the percentage of O2 bound to hemoglobin (%SaO2) by greater than or equal to 5% below resting values in some highly trained endurance athletes. We tested the hypothesis that pulmonary gas exchange limitations may restrict VO2max in highly trained athletes who exhibit exercise-induced hypoxemia. Twenty healthy male volunteers were divided into two groups according to their physical fitness status and the demonstration of exercise-induced reductions in %SaO2 less than or equal to 92%: 1) trained (T), mean VO2max = 56.5 ml.kg-1.min-1 (n = 13) and 2) highly trained (HT) with maximal exercise %SaO2 less than or equal to 92%, mean VO2max = 70.1 ml.kg-1.min-1 (n = 7). Subjects performed two incremental cycle ergometer exercise tests to determine VO2max at sea level under normoxic (21% O2) and mild hyperoxic conditions (26% O2). Mean %SaO2 during maximal exercise was significantly higher (P less than 0.05) during hyperoxia compared with normoxia in both the T group (94.1 vs. 96.1%) and the HT group (90.6 vs. 95.9%). Mean VO2max was significantly elevated (P less than 0.05) during hyperoxia compared with normoxia in the HT group (74.7 vs. 70.1 ml.kg-1.min-1). In contrast, in the T group, no mean difference (P less than 0.05) existed between treatments in VO2max (56.5 vs. 57.1 ml.kg-1.min-1). These data suggest that pulmonary gas exchange may contribute significantly to the limitation of VO2max in highly trained athletes who exhibit exercise-induced reductions in %SaO2 at sea level.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The Influence of Oxygen Saturation on the Relationship Between Hemoglobin Mass and VO2max

2018 ◽  
Vol 02 (04) ◽  
pp. E98-E104 ◽  
Author(s):  
Jesse Goodrich ◽  
Benjamin Ryan ◽  
William Byrnes
Keyword(s):  
Negative Relationship ◽  
Cycle Ergometer ◽  
Endurance Athletes ◽  
Moderate Altitude ◽  
Exercise Tests ◽  
Graded Exercise ◽  
Males And Females ◽  
Hemoglobin Mass ◽  
Exercise Induced ◽  
The Relationship

AbstractHemoglobin mass (tHb) is a key determinant of maximal oxygen uptake (VO2max). We examined whether oxyhemoglobin desaturation (ΔSaO2) at VO2max modifies the relationship between tHb and VO2max at moderate altitude (1,625 m). Seventeen female and 16 male competitive, endurance-trained moderate-altitude residents performed two tHb assessments and two graded exercise tests on a cycle ergometer to determine VO2max and ΔSaO2. In males and females respectively, VO2max (ml·kg−1·min−1) ranged from 62.5–83.0 and 44.5–67.3; tHb (g·kg−1) ranged from 12.1–17.5 and 9.1–13.0; and SaO2 at VO2max (%) ranged from 81.7–94.0 and 85.7–95.0. tHb was related to VO2max when expressed in absolute terms and after correcting for body mass (r=0.94 and 0.86, respectively); correcting by ΔSaO2 did not improve these relationships (r=0.93 and 0.83). Additionally, there was a negative relationship between tHb and SaO2 at VO2max (r=–0.57). In conclusion, across a range of endurance athletes at moderate altitude, the relationship between tHb and VO2max was found to be similar to that observed at sea level. However, correcting tHb by ΔSaO2 did not explain additional variability in VO2max despite significant variability in ΔSaO2; this raises the possibility that tHb and exercise-induced ΔSaO2 are not independent in endurance athletes.

scholarly journals Accuracy of two pulse-oximetry measurements for INTELLiVENT-ASV in mechanically ventilated patients: a prospective observational study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shinshu Katayama ◽  
Jun Shima ◽  
Ken Tonai ◽  
Kansuke Koyama ◽  
Shin Nunomiya
Keyword(s):  
Oxygen Saturation ◽  
Pulse Oximetry ◽  
Prospective Observational Study ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Arterial Blood Gas ◽  
Mechanically Ventilated ◽  
Mechanically Ventilated Patients ◽  
Arterial Blood ◽  
Ventilated Patients

AbstractRecently, maintaining a certain oxygen saturation measured by pulse oximetry (SpO2) range in mechanically ventilated patients was recommended; attaching the INTELLiVENT-ASV to ventilators might be beneficial. We evaluated the SpO2 measurement accuracy of a Nihon Kohden and a Masimo monitor compared to actual arterial oxygen saturation (SaO2). SpO2 was simultaneously measured by a Nihon Kohden and Masimo monitor in patients consecutively admitted to a general intensive care unit and mechanically ventilated. Bland–Altman plots were used to compare measured SpO2 with actual SaO2. One hundred mechanically ventilated patients and 1497 arterial blood gas results were reviewed. Mean SaO2 values, Nihon Kohden SpO2 measurements, and Masimo SpO2 measurements were 95.7%, 96.4%, and 96.9%, respectively. The Nihon Kohden SpO2 measurements were less biased than Masimo measurements; their precision was not significantly different. Nihon Kohden and Masimo SpO2 measurements were not significantly different in the “SaO2 < 94%” group (P = 0.083). In the “94% ≤ SaO2 < 98%” and “SaO2 ≥ 98%” groups, there were significant differences between the Nihon Kohden and Masimo SpO2 measurements (P < 0.0001; P = 0.006; respectively). Therefore, when using automatically controlling oxygenation with INTELLiVENT-ASV in mechanically ventilated patients, the Nihon Kohden SpO2 sensor is preferable.Trial registration UMIN000027671. Registered 7 June 2017.

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