Effekte zweier Sauerstoffsysteme (Flüssigsauerstoff versus Konzentrator) auf die Oxygenierung in Ruhe und während Belastung bei hypoxämischen COPD-Patienten
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Philipps-Universität Marburg
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The two most common oxygen delivery systems for hypoxemic COPD patients available operate with liquid oxygen or by concentrating the ambient air (concentrators). The concentrator system is advantageous, because it is powered by an integrated battery and charged with a common electrical plug, which enables the patient to have a higher level of physical mobility and autonomy. There are limited publications, that explore if portable oxygen concentrators have a comparable efficiency on oxygen saturation to liquid oxygen devices with continuous flow (LOD). As of now there are no official recommendations on how to convert the oxygen flow rate for LOD (litre per minute) into the corresponding level of the POC; therefore, the aim of this randomized, controlled cross-over trial is to investigate the comparability of the portable oxygen concentrator Activox™ 4L (POC) to a liquid oxygen device Companion® (LOD) in 30 hypoxemic COPD patients during exercise (means: age 65,6±8,2 year, FEV1 35,2±10,4%, pO2 56,8±6,1mmHg, pCO2 38,3±4,9mmHg) and in 15 patients at rest (means: age 65,5±7,6 year; FEV1 31,5±7,3%, pO2 54,9±3,5mmHg; pCO2 40,2±3,3mmHg). No drop-outs occurred. As a baseline assessment all patients received a body plethysmography and a blood gas analysis without using supplemental oxygen. Examination during exercise: A Shuttle Walk was used as a standardized field walking test to simulate a cardiopulmonary exercise test with daily life relevance. Following an initial incremental shuttle walk test (ISWT), patients performed on two days in randomized order with each system one endurance shuttle walk test (ESWT). During the ESWT, breathing frequency, inspiratory capacity, SpO2, pCO2 and heart frequency were measured, as well as Dyspnoea and leg fatigue before and after the ESWT were evaluated. SpO2 was significantly higher before and during the ESWT with the LOD than with the POC (all p˂.005). The mean SpO2±SD dropped during the ESWT with the LOD from 95,3±2,4% to a mean SpO2 of 88,9±6,2% at the end of the walking test, while it was with the POC 93,6±2,9% (Start) and 84,8±7% SpO2 (End). Patients with the POC showed a lower pre-walk SpO2 and a faster decline of Oxygenation during the walking test.
LOD supplied patients for a longer period of time with SpO2˃90% than with the POC. Therefore, patients were able to walk statistically significant (p˂.001) longer with the LOD during the ESWT. The mean distance and endurance with the LOD were 344,0±293,7 meter and 384±277 seconds, while with the POD it was with 235,7±249,8 meter and 261±219 seconds, consequently 108,3±138,0 meter and 123±160 seconds less than with the LOD. 24 of the 30 patients stopped the ESWT with the POC earlier than with the LOD. There was no significant statistical difference between the two devices regarding the second outcome parameters such as pCO2, breathing frequency, heart frequency, inspiratory capacity, as well as leg fatigue and dyspnoea (BORG-Scale). Examination at rest: The study was conducted during two consecutive days, where the 15 patients were connected in randomized order to one of the two systems via nasal cannula for a total time period of 40 minutes while remaining in a sitting position without speaking. The oxygen flow rate started at 1 liter/min (LOD) or Level 1 (POC) and increased every 10 minutes to the following level until it reached the maximum level at 4 (POC) or 4l/min (LOD). Blood gases (pO2, pCO2, pH) and breathing frequencies were measured at the end of each oxygen level. There was a significant difference between the two devices regarding the pO2 on all four flow rates (all p˂.001). On an average of all flow rates there was a 15,2±7,2mmHg higher pO2 measurable with the LOD. With an initial mean pO2 on level 1 of the POC with 58,0±5,2mmHg, the pO2 went up till 66,0±6,3mmHg on Level 4, reaching the maximum setting of oxygen flow of the POC. Patients with the LOD showed a mean pO2 with 1l/min-flowrate of 63,8±6,5mmHg and 87,4±15,9mmHg with a 4l/min flow. The maximum difference between the devices was reached on the maximum Level of the POC and 4l/min liquid oxygen with a 21,4±13,0mmHg lower oxygenation with the POC. On level 4, 14 of the 15 patients had a lower oxygenation than with the 2l/min liquid oxygen, 5 of these patients a lower pO2 than with 1l/min. Summarizing the POC had an effect per level on the patients pO2 as it had equivalent to 304ml/min liquid oxygen, reaching a maximum flow-capacity of the device on level 4 of 1,2l/min LOX. There was no significant difference between the two devices regarding the second outcome parameter such as pCO2, pH and breathing frequencies.
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Created: 2020Issued: 2020-03-19Updated: 2020-03-19
Faculty
Medizin
Publisher
Philipps-Universität Marburg
Language
ger
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DoctoralThesis
Keywords
Konzentratorconcentratoroxygen delivery systemsLODcontinous flowDemandDauerflussLiquid oxygen devicFlüssigsauerstoffdemandPOCliquid oxygenPortible oxygen concentratoroxygenationSauerstoffsystemeOxygenierung
DFG-subjects
KonzentratorSauerstoffsystemeEffekteVergleichOxygenierungDauerflussDemandFlüssigsauerstoffBelastungRuhe
DDC-Numbers
610
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Weingaertner, Julian: Effekte zweier Sauerstoffsysteme (Flüssigsauerstoff versus Konzentrator) auf die Oxygenierung in Ruhe und während Belastung bei hypoxämischen COPD-Patienten. : Philipps-Universität Marburg 2020-03-19. DOI: https://doi.org/10.17192/z2020.0163.