Validity of pulse oximetry during exercise in elite endurance athletes

1992 ◽  
Vol 72 (2) ◽  
pp. 455-458 ◽  
Author(s):  
D. Martin ◽  
S. Powers ◽  
M. Cicale ◽  
N. Collop ◽  
D. Huang ◽  
...  
Keyword(s):  
Pulse Oximeter ◽  
High Intensity ◽  
Aerobic Power ◽  
Constant Load ◽  
Cycle Exercise ◽  
Exercise Tests ◽  
Arterial Blood ◽  
Highly Correlated ◽  
Pulse Oximeters ◽  
Finger Probe

Eleven highly trained male cyclists [maximal aerobic power (VO2max) = 70.6 +/- 4.2 ml.kg-1.min-1] performed both high intensity constant load (90–95% VO2max) and incremental cycle exercise tests with arterial blood sampling to evaluate the accuracy of pulse oximeter estimates (%SpO2) of arterial oxyhemoglobin fraction of total hemoglobin (%HbO2). Three subjects also performed an incremental exercise test in hypoxic conditions (inspired partial pressure of O2 = 89, 93, or 100 Torr). Arterial %HbO2 was determined via CO-oximetry and ranged from 72 to 99%. Three Ohmeda 3740 pulse oximeters were used to estimate %HbO2, one on each ear lobe and a finger probe. The finger probe tended to provide the best estimate of %HbO2 during exercise: the mean %SpO2 - %HbO2 difference for 232 exercise observations was 0.52 +/- 1.36% (SD). Finger probe %SpO2 and %HbO2 were highly correlated [r = 0.98, standard error of the estimate (SEE) = 1.32%, P less than 0.0001]. The accuracy of pulse oximeters has been questioned during high-intensity exercise. When aerobic power was greater than 81% of VO2max (n = 75), the finger probe's mean error was -0.01 +/- 1.40%. Finger probe %SpO2 and %HbO2 were highly correlated (r = 0.97, SEE = 1.32%, P less than 0.0001). These results indicate that this pulse oximeter is a valid predictor of %HbO2 in elite athletes during cycle exercise.

scholarly journals Bedside Pulse Oximeters with a Clinical Algorithm Make Economic Sense in the Intensive Care Unit

1996 ◽  
Vol 3 (1) ◽  
pp. 47-51
Author(s):  
David J Leasa ◽  
Jacqueline M Walker
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Pulse Oximeter ◽  
Cost Savings ◽  
Clinical Algorithm ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Before And After ◽  
The Mean ◽  
Pulse Oximeters

OBJECTIVE:To determine the effect on arterial blood gas (ABG) and hospital resource use by introducing a strategy of using bedside oximeters with a clinical algorithm, based on the argument that bedside pulse oximeters make economic sense in the intensive care unit (ICU) if safe patient oxygenation can be ensured at a lower cost than that of existing monitoring options.DESIGN:A before and after design was used to examine the consequences of a pulse oximeter at each bedside in the ICU along with a pulse oximeter clinical algorithm (POCA) describing use for titrating oxygen therapy and for performing ABG analysis.SETTING:A 19-bed multidisciplinary ICU with a six-bed extended ICU (EICU) available to function as a 'step-down' facility.PATIENTS:All patients admitted to the ICU/EICU over two 12-month periods were included.RESULTS:The strategy yielded a 31% reduction in the mean number of ABGs per patient after POCA (20.0±26.1 versus 13.8±16.7, mean ± SD; P<0.001) as well as a potential annual cost savings of $32,831.CONCLUSIONS:Bedside oximeters within the ICU, when used with explicit guidelines, reduce ABG use and result in hospital cost savings.

scholarly journals Pulse Oximetry with Two Infrared Wavelengths without Calibration in Extracted Arterial Blood

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3457 ◽  
Author(s):  
Ohad Yossef Hay ◽  
Meir Cohen ◽  
Itamar Nitzan ◽  
Yair Kasirer ◽  
Sarit Shahroor-karni ◽  
...  
Keyword(s):  
Pulse Oximetry ◽  
Pulse Oximeter ◽  
Breath Holding ◽  
Arterial Line ◽  
Non Invasive ◽  
Arterial Blood ◽  
Infrared Wavelengths ◽  
Path Lengths ◽  
Similar Accuracy ◽  
Pulse Oximeters

Oxygen saturation in arterial blood (SaO2) provides information about the performance of the respiratory system. Non-invasive measurement of SaO2 by commercial pulse oximeters (SpO2) make use of photoplethysmographic pulses in the red and infrared regions and utilizes the different spectra of light absorption by oxygenated and de-oxygenated hemoglobin. Because light scattering and optical path-lengths differ between the two wavelengths, commercial pulse oximeters require empirical calibration which is based on SaO2 measurement in extracted arterial blood. They are still prone to error, because the path-lengths difference between the two wavelengths varies among different subjects. We have developed modified pulse oximetry, which makes use of two nearby infrared wavelengths that have relatively similar scattering constants and path-lengths and does not require an invasive calibration step. In measurements performed on adults during breath holding, the two-infrared pulse oximeter and a commercial pulse oximeter showed similar changes in SpO2. The two pulse oximeters showed similar accuracy when compared to SaO2 measurement in extracted arterial blood (the gold standard) performed in intensive care units on newborns and children with an arterial line. Errors in SpO2 because of variability in path-lengths difference between the two wavelengths are expected to be smaller in the two-infrared pulse oximeter.

Intensity-dependent tolerance to exercise after attaining V̇o2 max in humans

2003 ◽  
Vol 95 (2) ◽  
pp. 483-490 ◽  
Author(s):  
Edward M. Coats ◽  
Harry B. Rossiter ◽  
James R. Day ◽  
Akira Miura ◽  
Yoshiyuki Fukuba ◽  
...  
Keyword(s):  
High Intensity ◽  
Critical Power ◽  
Load Cycle ◽  
Constant Load ◽  
Cycle Ergometer ◽  
Work Rate ◽  
Hyperbolic Function ◽  
Exercise Tests ◽  
Ergometer Exercise

The tolerable duration of high-intensity, constant-load cycle ergometry is a hyperbolic function of power, with an asymptote termed critical power (CP) and a curvature constant (W′) with units of work. It has been suggested that continued exercise after exhaustion may only be performed below CP, where predominantly aerobic energy transfer can occur and W′ can be partially replenished. To test this hypothesis, six volunteers each performed cycle-ergometer exercise with breath-by-breath determination of ventilatory and pulmonary gas exchange variables. Initially, four exercise tests to exhaustion were made: 1) a ramp-incremental and 2) three high-intensity constant-load bouts at different work rates, to estimate lactate (θ̂L) and CP thresholds, W′, and maximum oxygen uptake (V̇o2 max). Subsequently, subjects cycled to the limit of tolerance (for ∼360 s) on three occasions, each followed by a work rate reduction to 1) 110% CP, 2) 90% CP, and 3) 80% θ̂L for a 20-min target. W′ averaged 20.9 ± 2.35 kJ or 246 ± 30 J/kg. After initial fatigue, 110% CP was tolerated for only 30 ± 12 s. Each subject completed 20 min at 80% θ̂L, but only two sustained 20 min at 90% CP; the remaining four subjects fatigued at 577 ± 306 s, with oxygen consumption at 89 ± 8% V̇o2 max. The results support the suggestion that replenishing W′ after fatigue necessitates a sub-CP work rate. The variation in subjects' responses during 90% CP was unexpected but consistent with mechanisms such as reduced CP consequent to prior high-intensity exercise, variation in lactate handling, and/or regional depletion of energy substrates, e.g., muscle glycogen.

scholarly journals Influence of acute plasma volume expansion on V̇o2 kinetics, V̇o2peak, and performance during high-intensity cycle exercise

2006 ◽  
Vol 101 (3) ◽  
pp. 707-714 ◽  
Author(s):  
Nicolas J. A. Berger ◽  
Iain T. Campbell ◽  
Daryl P. Wilkerson ◽  
Andrew M. Jones
Keyword(s):  
Gas Exchange ◽  
Plasma Volume ◽  
High Intensity ◽  
Volume Expansion ◽  
Time To Exhaustion ◽  
Cycle Exercise ◽  
Step Cycle ◽  
Plasma Volume Expansion ◽  
Exercise Tests ◽  
Ergometer Exercise

The purpose of this study was to examine the influence of acute plasma volume expansion (APVE) on oxygen uptake (V̇o2) kinetics, V̇o2peak, and time to exhaustion during severe-intensity exercise. Eight recreationally active men performed “step” cycle ergometer exercise tests at a work rate requiring 70% of the difference between the gas-exchange threshold and V̇o2max on three occasions: twice as a “control” (Con) and once after intravenous infusion of a plasma volume expander (Gelofusine; 7 ml/kg body mass). Pulmonary gas exchange was measured breath by breath. APVE resulted in a significant reduction in hemoglobin concentration (preinfusion: 16.0 ± 1.0 vs. postinfusion: 14.7 ± 0.8 g/dl; P < 0.001) and hematocrit (preinfusion: 44 ± 2 vs. postinfusion: 41 ± 3%; P < 0.01). Despite this reduction in arterial O2 content, APVE had no effect on V̇o2 kinetics (phase II time constant, Con: 33 ± 15 vs. APVE: 34 ± 12 s; P = 0.74), and actually resulted in an increased V̇o2peak (Con: 3.90 ± 0.56 vs. APVE: 4.12 ± 0.55 l/min; P = 0.006) and time to exhaustion (Con: 365 ± 58 vs. APVE: 424 ± 64 s; P = 0.04). The maximum O2 pulse was also enhanced by the treatment (Con: 21.3 ± 3.4 vs. APVE: 22.7 ± 3.4 ml/beat; P = 0.04). In conclusion, APVE does not alter V̇o2 kinetics but enhances V̇o2peak and exercise tolerance during high-intensity cycle exercise in young recreationally active subjects.

Pulse Oximetry: An Alternative Method for the Assessment of Oxygenation in Newborn Infants

PEDIATRICS ◽  
1987 ◽  
Vol 79 (4) ◽  
pp. 524-528
Author(s):  
Michael S. Jennis ◽  
Joyce L. Peabody
Keyword(s):  
Pulse Oximetry ◽  
Pulse Oximeter ◽  
Arterial Oxygen Saturation ◽  
Newborn Infants ◽  
Fetal Hemoglobin ◽  
Arterial Oxygen ◽  
Skin Injury ◽  
Reliable Technique ◽  
Arterial Blood

Continuous monitoring of oxygenation in sick newborns is vitally important. However, transcutaneous Po2 measurements have a number of limiations. Therefore, we report the use of the pulse oximeter for arterial oxygen saturation (Sao2) determination in 26 infants (birth weights 725 to 4,000 g, gestational ages 24 to 40 weeks, and postnatal ages one to 49 days). Fetal hemoglobin determinations were made on all infants and were repeated following transfusion. Sao2, readings from the pulse oximeter were compared with the Sao2 measured in vitro on simultaneously obtained arterial blood samples. The linear regression equation for 177 paired measurements was: y = 0.7x + 27.2; r = .9. However, the differences between measured Sao2 and the pulse oximeter Sao2 were significantly greater in samples with &gt; 50% fetal hemoglobin when compared with samples with &lt; 25% fetal hemoglobin (P &lt; .001). The pulse oximeter was easy to use, recorded trends in oxygenation instantaneously, and was not associated with skin injury. We conclude that pulse oximetry is a reliable technique for the continuous, noninvasive monitoring of oxygenation in newborn infants.

Threshold for muscle lactate accumulation during progressive exercise

1989 ◽  
Vol 66 (6) ◽  
pp. 2710-2716 ◽  
Author(s):  
J. Chwalbinska-Moneta ◽  
R. A. Robergs ◽  
D. L. Costill ◽  
W. J. Fink
Keyword(s):  
Blood Lactate ◽  
Bicycle Ergometer ◽  
Exercise Tests ◽  
Muscle Lactate ◽  
Lactate Accumulation ◽  
Ergometer Exercise ◽  
Progressive Exercise ◽  
Blood Lactate Accumulation ◽  
Highly Correlated ◽  
The Relationship

The purpose of this study was to investigate the relationship between muscle and blood lactate concentrations during progressive exercise. Seven endurance-trained male college students performed three incremental bicycle ergometer exercise tests. The first two tests (tests I and II) were identical and consisted of 3-min stage durations with 2-min rest intervals and increased by 50-W increments until exhaustion. During these tests, blood was sampled from a hyperemized earlobe for lactate and pH measurement (and from an antecubital vein during test I), and the exercise intensities corresponding to the lactate threshold (LT), individual anaerobic threshold (IAT), and onset of blood lactate accumulation (OBLA) were determined. The test III was performed at predetermined work loads (50 W below OBLA, at OBLA, and 50 W above OBLA), with the same stage and rest interval durations of tests I and II. Muscle biopsies for lactate and pH determination were taken at rest and immediately after the completion of the three exercise intensities. Blood samples were drawn simultaneously with each biopsy. Muscle lactate concentrations increased abruptly at exercise intensities greater than the “below-OBLA” stage [50.5% maximal O2 uptake (VO2 max)] and resembled a threshold. An increase in blood lactate and [H+] also occurred at the below-OBLA stage; however, no significant change in muscle [H+] was observed. Muscle lactate concentrations were highly correlated to blood lactate (r = 0.91), and muscle-to-blood lactate ratios at below-OBLA, at-OBLA, and above-OBLA stages were 0.74, 0.63, 0.96, and 0.95, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Muscle Na+-K+-ATPase response during 16 h of heavy intermittent cycle exercise

2007 ◽  
Vol 293 (2) ◽  
pp. E523-E530 ◽  
Author(s):  
H. J. Green ◽  
T. A. Duhamel ◽  
G. P. Holloway ◽  
J. W. Moule ◽  
J. Ouyang ◽  
...  
Keyword(s):  
Aerobic Power ◽  
Intermittent Exercise ◽  
Binding Capacity ◽  
Vastus Lateralis ◽  
Intrinsic Activity ◽  
Cycle Exercise ◽  
Maximum Binding Capacity ◽  
Phosphatase Assay ◽  
Quantitative Immunoblotting

This study investigated the effects of a 16-h protocol of heavy intermittent exercise on the intrinsic activity and protein and isoform content of skeletal muscle Na+-K+-ATPase. The protocol consisted of 6 min of exercise performed once per hour at ∼91% peak aerobic power (V̇o2 peak) with tissue sampling from vastus lateralis before (B) and immediately after repetitions 1 (R1), 2 (R2), 9 (R9), and 16 (R16). Eleven untrained volunteers with a V̇o2 peak of 44.3 ± 2.3 ml·kg−1·min−1 participated in the study. Maximal Na+-K+-ATPase activity ( Vmax, in nmol·mg protein−1·h−1) as measured by the 3- O-methylfluorescein K+-stimulated phosphatase assay was reduced ( P < 0.05) by ∼15% with exercise regardless of the number of repetitions performed. In addition, Vmax at R9 and R16 was lower ( P < 0.05) than at R1 and R2. Vanadate-facilitated [3H]ouabain determination of Na+-K+-ATPase content (maximum binding capacity, pmol/g wet wt), although unaltered by exercise, increased ( P < 0.05) 8.3% by R9 with no further increase observed at R16. Assessment of relative changes in isoform abundance measured at B as determined by quantitative immunoblotting showed a 26% increase ( P < 0.05) in the α2-isoform by R2 and a 29% increase in α3 by R9. At R16, β3 was lower ( P < 0.05) than at R2 and R9. No changes were observed in α1, β1, or β2. It is concluded that repeated sessions of heavy exercise, although resulting in increases in the α2- and α3-isoforms and decreases in β3-isoform, also result in depression in maximal catalytic activity.

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