Performance of a Demand Oxygen Saver System during Rest, Exercise, and Sleep in Hypoxemic Patients

doi:10.1378/chest.94.1.77

Chest

Volume 94, Issue 1, July 1988, Pages 77-80

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Demand oxygen systems have been shown to be effective in treating hypoxemia during seated rest and during exercise, but the performance of these systems during sleep has not been previously studied. We compared the efficacy of a new demand oxygen saver system with that of continuous flow nasal oxygen during the usual activities of daily life including sleep, seated rest, and exercise. Six hypoxemic patients were studied. All six had chronic obstructive pulmonary disease, though one patient had kyphoscoliosis with mixed obstructive and restrictive lung disease. Patients were studied during each activity of daily life while receiving supplemental oxygen by continuous flow nasal cannula at 2 liters per minute and during use of the demand oxygen saver system. The demand oxygen system produced arterial oxygenation equivalent to continuous flow nasal cannula under all conditions while utilizing substantially less oxygen. When compared with administration of oxygen by continuous flow nasal cannula, the demand oxygen saver cannula utilized only 45 percent as much oxygen during seated rest, 44 percent as much oxygen during exercise, and 39 percent as much oxygen during sleep. Our data support the use of demand oxygen systems for treatment of hypoxemia in patients with chronic obstructive lung disease.

Section snippets

Study Population

Six patients were selected for study. All had chronic lung disease with resultant hypoxemia, and all were judged clinically stable. All but one subject had a PaO₂ of 58 mm Hg or less breathing room air on the first day of study. The one exception, subject 1, had an initial PaO₂ measured at 62 mm Hg but was retained as a study subject because a second arterial sample drawn later the first study day did demonstrate a PaO₂ of less than 59 mm Hg. The two subjects with PaO₂ values during room air

Seated Rest

Table 2 lists the results of blood gas testing after one hour of seated rest on the two oxygen delivery systems and the percentage oxygen use with the COS. As Figure 1 illustrates, arterial Po₂ values achieved by the two systems fall very near the line of identity. Oxygen saturation data obtained from ear oximetry yielded very similar results, but the increased sensitivity of oxygen partial pressure measurements in the range of values observed lead us to emphasize blood gas data for this

Discussion

The development of oxygen delivery systems designed to maintain adequate arterial oxygenation while utilizing less oxygen has been motivated by the desire to reduce the cost of oxygen administration and to provide patients with prolonged oxygen availability from portable oxygen sources. Although there has been increasing evidence that these goals can be achieved, the widespread use of oxygen conserving devices awaits demonstration that these devices are durable and will function reliably under

References (12)

M Soffer et al.
Conservation of oxygen supply using a reservoir nasal cannula in hypoxemic patients at rest and during exercise
Chest
(1985)
BL Tiep et al.
A new pendant storage oxygen-conserving nasal cannula
Chest
(1985)
BL Tiep et al.
Low-concentration oxygen therapy via a demand oxygen delivery system
Chest
(1985)
M Mecikalski et al.
A demand value conserves oxygen in subjects with chronic obstructive pulmonary disease
Chest
(1984)
D Auerbach et al.
A new oxygen cannula system using intermittent-demand nasal flow
Chest
(1978)
M Rinow et al.
Effectiveness of a new demand valve in chronic hypoxemia
Chest
(1986)

There are more references available in the full text version of this article.

Cited by (42)

Comparison of supplemental oxygen delivery by continuous versus demand based flow systems in hypoxemic COPD patients – A randomized, single-blinded cross-over study
2019, Respiratory Medicine
Citation Excerpt :
Up to now there are only few studies that compared DODS and CF oxygen devices and results are heterogeneous. Two studies found that DODS devices are inferior to maintain oxygen saturation compared to CF devices in COPD patients during exercise [16,17] while other studies found no relevant differences concerning the oxygen saturation during exercise [14,18–22]. These studies used the 6- or 12-minute walk test, an incremental shuttle walk test or treadmill walking for exercise.
Supplemental oxygen is a recommended therapy option in stable hypoxemic COPD patients. Often, supplemental oxygen is provided by continuous flow (CF). However, demand oxygen delivery systems (DODS) that provide an oxygen bolus only during inspiration have gained increasing use as they prolong oxygen cylinder life (beside battery life). However, there is a lack of evidence if different DODS and CF devices are equivalent.
Seventy hypoxemic COPD patients (FEV₁ 32 ± 9% predicted, PaO₂ 56±7 mmHg) on long-term oxygen therapy were included in this prospective single-blinded, randomized cross-over trial. Following an initial incremental shuttle walk test, patients performed 3 endurance shuttle walk tests (ESWT) at 85% of their maximum walking speed in random order with: (A) CF (ESWT-CF), (B) a DODS based on liquid oxygen (ESWT-DL) and (C) an DODS oxygen concentrator (ESWT-DC). The primary outcome was oxygen saturation (SpO₂) at ESWT isotime. Secondary outcomes were total ESWT duration, heart rate (HR) and breathing frequency (BF) at isotime and dyspnea at end-exercise.
SpO₂ at ESWT isotime was not clinically different between devices: 90 ± 4% (CF), 89 ± 5% (DL) and 90 ± 5% (DC). However, 20% of the patients showed a ≥4% lower oxygen desaturation while using a DODS device. Secondary outcomes were similar under the three conditions.
Oxygen supplementation via DODS (based on liquid oxygen or as a concentrator) yielded comparable physiological effects during standardized walking in stable hypoxemic COPD patients like CF. However, 20% of patients showed a clinically relevant lower oxygen saturation while using a DODS device. Therefore, we suggest individual testing of oxygen saturation of DODS suitability.
Long-Term Oxygen Therapy
2009, Asthma and COPD
This chapter reviews the known effects of chronic oxygen therapy, its indications, and the various delivery systems now available. Oxygen therapy has become very important in the treatment of severe chronic obstructive pulmonary disease (COPD). Long-term oxygen improves survival in hypoxemic COPD. Other benefits of oxygen include better exercise tolerance, decreased dyspnea, and improvements in neuropsychological performance. In addition, there appear to be beneficial effects on pulmonary hemodynamics, sleep quality, reduced minute ventilation, and WOB. Hypoxemia is defined as an abnormally low arterial oxygen tension P_aO₂. The physiologic causes of hypoxemia include a low inspired partial pressure of oxygen, abnormal ventilation–perfusion relationship, decreased diffusion capacity, alveolar hypoventilation, and right to left shunt. Oxygen therapy increases the F_iO₂ and is the primary treatment for hypoxemia resulting from the first three causes. The hypoxemia of alveolar hypoventilation is best treated by increased ventilation while a true shunt is by definition unresponsive to hyperoxia. Although the reason for increased survival with oxygen is not clear, there is evidence that O₂ can improve pulmonary hemodynamics and leads to reduced cardiac work and greater oxygen delivery. The consequences of exercise induced and nocturnal desaturation are not absolutely known. Clinicians should be aware of air travel-induced hypoxemia in COPD and be able to identify those who need oxygen in flight. Once a patient meets the criteria for oxygen prescription, the physician must complete the certificate of Medical Necessity Form specifying the indication for oxygen, type of system and liter flow at rest, exercise and sleep.
Long-term oxygen therapy
2008, Asthma and COPD: Basic Mechanisms and Clinical Management
This chapter reviews the known effects of chronic oxygen therapy, its indications, and the various delivery systems now available. Oxygen therapy has become very important in the treatment of severe chronic obstructive pulmonary disease (COPD). Long-term oxygen improves survival in hypoxemic COPD. Other benefits of oxygen include better exercise tolerance, decreased dyspnea, and improvements in neuropsychological performance. In addition, there appear to be beneficial effects on pulmonary hemodynamics, sleep quality, reduced minute ventilation, and WOB. Hypoxemia is defined as an abnormally low arterial oxygen tension P_aO₂. The physiologic causes of hypoxemia include a low inspired partial pressure of oxygen, abnormal ventilation–perfusion relationship, decreased diffusion capacity, alveolar hypoventilation, and right to left shunt. Oxygen therapy increases the F_iO₂ and is the primary treatment for hypoxemia resulting from the first three causes. The hypoxemia of alveolar hypoventilation is best treated by increased ventilation while a true shunt is by definition unresponsive to hyperoxia. Although the reason for increased survival with oxygen is not clear, there is evidence that O₂ can improve pulmonary hemodynamics and leads to reduced cardiac work and greater oxygen delivery. The consequences of exercise induced and nocturnal desaturation are not absolutely known. Clinicians should be aware of air travel-induced hypoxemia in COPD and be able to identify those who need oxygen in flight. Once a patient meets the criteria for oxygen prescription, the physician must complete the certificate of Medical Necessity Form specifying the indication for oxygen, type of system and liter flow at rest, exercise and sleep.
Oxygen-conserving devices: A forgotten resource
2007, Archivos de Bronconeumologia
Los sistemas de ahorro de oxígeno agrupan el catéter transtraqueal, las cánulas reservorio y los sistemas a demanda. Su objetivo es aumentar la autonomía de las fuentes de oxígeno portátiles consiguiendo una corrección de la hi-poxemia con menor flujo de oxígeno. El catéter transtraqueal aumenta la fracción inspiratoria de oxígeno al proporcionar oxígeno directamente en la tráquea, lo que evita el espacio muerto de la cavidad orofaríngea y favorece que la vía aérea superior actúe como reservorio. Las cánulas reservorio aumentan la fracción inspiratoria de oxígeno al inicio de la inspiración. Los sistemas a demanda cuentan con una válvula que se activa con la inspiración, de modo que se administra oxígeno sólo durante esta fase del ciclo respiratorio. Debido a sus diferentes características, cada sistema presenta ventajas e inconvenientes. Para su correcta prescripción debe ajustarse individualmente el flujo de oxígeno tanto en reposo como durante el ejercicio o el sueño con las pruebas pertinentes.
Oxygen-conserving devices include transtracheal catheters, reservoir cannulas, and demand oxygen delivery systems. They are designed to extend the amount of time portable oxygen cylinders will last and correct hypoxemia with a lower flow of oxygen. Transtracheal catheters increase the fraction of inspired oxygen by delivering oxygen directly to the trachea, bypassing the dead space of the oropharynx and improving the efficiency of the upper airway as a reservoir. Reservoir cannulas increase the fraction of inspired oxygen at the beginning of the inspiratory phase. Demand oxygen delivery systems have a valve that is activated during inspiration, meaning that oxygen is only delivered during this stage of the respiratory cycle. Each system has advantages and disadvantages arising from differing design features. Prescription should be based on individual tests in all cases to ensure optimal oxygen delivery during rest, exercise, and sleep.
Comparison of two demand oxygen delivery devices for administration of oxygen in COPD
2005, Chest
Citation Excerpt :
When a DODS is being titrated, oxygen should be administered for > 15 min before a blood gas analysis is performed, since the Po2 continues to increase between the 15 and 30 min of use. This is also in conformity with the results of other publications,710 in which oxygen equilibrium was established only after 30 min. In other studies, measurements were carried out after only 10 min11 or 15 min.12
Demand oxygen delivery systems (DODSs) were developed to secure the mobility of patients requiring oxygen therapy. The aim of the present study was to compare the efficacy of two currently available DODS with continuous oxygen administration (CONT).
Thirteen patients with COPD (mean [± SD] FEV₁, 28 ± 5.2% predicted; mean Po₂, 56.4 ± 8.1 mm Hg [breathing room air]).
Treatment for 30 min with CONT at a flow rate of 2 L/min, with the DODSs Oxytron 3 (Weinmann; Hamburg, Germany) or DeVilbiss EX 3000 (Somerset, PA) in random sequence. Arterialized blood samples were obtained from a hyperaemized ear lobe after 15 and 30 min.
After 15 min, no significant differences in Po₂ or arterial oxygen saturation (Sao₂) were observed. In comparison with CONT (mean Po₂, 70.5 ± 10.4 mm Hg; mean Sao₂, 94.8 ± 2.13%), oxygenation with the Oxytron 3 (mean Po₂, 66.3 ± 10.3 mm Hg; mean Sao₂, 93.5 ± 2.6%) was significantly less after 30 min when measured independently by blood gas analysis and pulse oximetry. The DeVilbiss EX 3000 (mean Po₂, 69.1 ± 12.0 mm Hg; mean Sao₂, 94.5 ± 3.2%) and CONT showed no differences.
Po₂ did not reach equilibrium after 15 min of treatment with the DODSs. The titration of a patient to a DODS is recommended, since simply accepting the manufacturer's information on oxygen equivalent does not guarantee an adequate supply of oxygen.
Comparison of four demand oxygen delivery systems at rest and during exercise for chronic obstructive pulmonary disease
2004, Respiratory Medicine
Citation Excerpt :
No other long-term efficacy and safety data are available. Nocturnal oxygenation seems satisfactory.6,13,20 Similar sleep quality with DODS and CFO has been reported, with the DODS providing 60% oxygen savings.5
Objectives: The aim of this study was to assess the performance of four demand oxygen delivery systems (DODS) in improving oxygenation and effort tolerance, at rest and during exercise, in chronic obstructive pulmonary disease (COPD) patients.
Materials and methods: Thirteen COPD patients were prospectively included. Four DODS (Oxiclip, Versatile, Venture and Impulse) were compared with continuous-flow oxygen (CFO).Nine of these patients performed 6-min walking tests on room air and on 3 l/min oxygen by DODS and CFO; Oxygen saturation, walking distance and the Borg dyspnea score were recorded.
Results: With all four DODS devices arterial oxygenation was improved with lower oxygen flow rates than with CFO. Oxygen economy was best with Impulse, but at a cost of less satisfactory oxygenation. Exercise desaturation was similar with CFO, Oxiclip, Venture, and Impulse but significantly higher with Versatile (P<0.05). Borg dyspnea scores were similar with CFO, Oxiclip, Venture, and Versatile but worse with Impulse (P<0.05). There was no significant difference in walking distances.
Conclusions: All four DODS improved oxygen saturation and saved oxygen. However, performance was better with the two devices (Oxiclip and Venture) that deliver a bolus of oxygen at inspiration onset.

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: Manuscript received June 25; revision accepted January 29.

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Chest

Clinical InvestigationsPerformance of a Demand Oxygen Saver System during Rest, Exercise, and Sleep in Hypoxemic Patients

Section snippets

Study Population

Seated Rest

Discussion

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Clinical Investigations
Performance of a Demand Oxygen Saver System during Rest, Exercise, and Sleep in Hypoxemic Patients