Comparison of invasive and noninvasive saturation monitoring in prescribing oxygen during exercise in COPD patients

Carone, Mauro; Patessio, A; Appendini, Lorenzo; Purro, Andrea; Czernicka, E; Zanaboni, S; Cf, Donner

doi:10.1183/09031936.97.10020446

Cited by 18 publications

(15 citation statements)

References 21 publications

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“…The presence of high carboxyhemoglobin values in heavy smokers could disturb the SpO2 reading by the pulse oximeter [22]. Many patients with lung cancer have some degree of chronic obstructive pulmonary disease (COPD), a condition in which SpO2 may not accurately represent arterial oxygen saturation [23]. Furthermore, the small sample size, heterogeneity of therapeutic approaches, and absence of full data on pulmonary comorbidity or carboxyhemoglobin values limit generalization of our model.…”

Section: Discussionmentioning

confidence: 99%

Lung cancer symptoms and pulse oximetry in the prognostic assessment of patients with lung cancer

Martins

Cavamura

et al. 2005

BMC Cancer

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Background: Medical oncologists continue to use performance status as a proxy for quality of life (QOL) measures, as completion of QOL instruments is perceived as time consuming, may measure aspects of QOL not affected by cancer therapy, and interpretation may be unclear. The pulse oximeter is widely used in clinical practice to predict cardiopulmonary morbidity after lung resection in cancer patients, but little is known on its role outside the surgical setting. We evaluated whether the Lung Cancer Symptom Scale and pulse oximetry may contribute to the evaluation of lung cancer patients who received standard anticancer therapy.

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Section: Discussionmentioning

confidence: 99%

Lung cancer symptoms and pulse oximetry in the prognostic assessment of patients with lung cancer

Martins

Cavamura

et al. 2005

BMC Cancer

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“…[3] can be nonzero since arterial blood is not necessarily fully oxygenated (typically, arterial saturation is 95% to 98% (20)), thus Δχ a > 0, typically holds for the susceptibility difference between arterial blood and reference tissue. However, in some pathologic conditions, such as in hypoxemia (insufficient oxygenation of arterial blood), for instance due to pulmonary insufficiency, arterial oxygen saturation is <90% (21). The angular and position dependence of the incremental field outside the tilted vein is described by the second term of Eq.…”

Section: Methodsmentioning

confidence: 99%

Accuracy and precision of MR blood oximetry based on the long paramagnetic cylinder approximation of large vessels

Langham

Magland

Epstein

et al. 2009

Magnetic Resonance in Med

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An accurate noninvasive method to measure the hemoglobin oxygen saturation (%HbO 2 ) of deep-lying vessels without catheterization would have many clinical applications. Quantitative MRI may be the only imaging modality that can address this difficult and important problem. MR susceptometry-based oximetry for measuring blood oxygen saturation in large vessels models the vessel as a long paramagnetic cylinder immersed in an external field. The intravascular magnetic susceptibility relative to surrounding muscle tissue is a function of oxygenated hemoglobin (HbO 2 ) and can be quantified with a field-mapping pulse sequence. In this work, the method's accuracy and precision was investigated theoretically on the basis of an analytical expression for the arbitrarily oriented cylinder, as well as experimentally in phantoms and in vivo in the femoral artery and vein at 3T field strength. Errors resulting from vessel tilt, noncircularity of vessel cross-section, and induced magnetic field gradients were evaluated and methods for correction were designed and implemented. Hemoglobin saturation was measured at successive vessel segments, differing in geometry, such as eccentricity and vessel tilt, but constant blood oxygen saturation levels, as a means to evaluate measurement consistency. The average standard error and coefficient of variation of measurements in phantoms were <2% with tilt correction alone, in agreement with theory, suggesting that high accuracy and reproducibility can be achieved while ignoring noncircularity for tilt angles up to about 30°. In vivo, repeated measurements of %HbO 2 in the femoral vessels yielded a coefficient of variation of less than 5%. In conclusion, the data suggest that %HbO 2 can be measured Key words: magnetic resonance oximetry; blood oxygen saturation; phase imaging; demagnetizing field; magnetic resonance susceptometry Accurate noninvasive measurement of hemoglobin oxygen saturation (%HbO 2 ) of deep-lying vessels inaccessible to pulse oximetry would have many clinical applications. Among these are the quantification of global cerebral metabolic rate of oxygen (CMRO 2 ) and the assessment of congenital heart defects in pediatric patients. Generally, both currently require catheterization procedures, which are invasive and carry risks. In the case of jugular bulb oximetry, the risks (1) include arterial puncture (between 1% and 4.5% has been reported in the literature), jugular vein occlusion from misplacement of catheter, and subclinical thrombosis, whose incidence rate is as high as 40%. Furthermore, accuracy is highly dependent on the position of the catheter against the vessel wall, and simultaneous measurement of both the left and right sides is not possible but important due to asymmetric venous drainage (2).Noninvasive quantification of blood oxygenation can be achieved with MRI by measuring T 2 (3) or T * 2 (4), or from a measurement of the relative susceptibility (5-7) of intravascular blood since all three quantities depend on the volume fraction of oxygenated hemoglobi...

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“…In the subsequent tests, oxygen flow rates were increased following a previously-published protocol. 22 Thus, if the SpO 2 in the preceding 6-min walk test had been: 1) 86e90%, in the successive test the increment was 1 l$min À1 ; 2) 81e85%, the increment was 2 l$min À1 ; and 3) <80%, the increment was 3 l$min À1 . Patients rested for 20 min between each walking test.…”

Section: Exercise Oxygen Prescriptionmentioning

confidence: 98%

Exercise oxygen flow titration methods in COPD patients with respiratory failure

Galera

Casitas

Martínez

et al. 2012

Respiratory Medicine

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We compare the adequacy of several titration procedures of oxygen flow in maintaining SpO(2) > 90% during the activities of daily life in patients with very severe COPD. Thirty-one very severe COPD patients undergoing oxygen-therapy were recruited. Three titration methods were randomly performed: (1) 6-min walking tests; (2) cycle-ergometer constant work-rate tests at a load equivalent to 12 ml/min/kg of oxygen uptake; (3) one single constant work-rate test at 40 W 12-h pulse-oximeter monitoring was performed on four consecutive days with the following oxygen flow during exercise: 1 l·min(-1) above the resting prescription (NOTT guidelines) and those established by the titration procedures. The time spent SpO(2) < 90% was higher for the titration based on NOTT and walking tests than for the oxygen flow established by the constant work-rate tests at 12 ml O(2)/min/kg (22.1 ± 18.7, 20.8 ± 19.5 and 6.7 ± 12.7%, respectively). As for the oxygen uptake-based titration, the simplified procedure (a single exercise test at 40 w) generates longer times spent SpO(2) < 90% and SpO(2) < 85%, although it maintains a SpO(2) > 90% for more 90% of the time. In COPD patients, exercise oxygen flow titrations by NOTT guidelines or walking tests do not allow a suitable oxygenation during the activities of daily life. Two more adequate alternative methods, based on constant work-rate tests, are proposed.

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Comparison of invasive and noninvasive saturation monitoring in prescribing oxygen during exercise in COPD patients

Cited by 18 publications

References 21 publications

Lung cancer symptoms and pulse oximetry in the prognostic assessment of patients with lung cancer

Lung cancer symptoms and pulse oximetry in the prognostic assessment of patients with lung cancer

Accuracy and precision of MR blood oximetry based on the long paramagnetic cylinder approximation of large vessels

Exercise oxygen flow titration methods in COPD patients with respiratory failure

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