Portable Oxygen Research Articles

Clinical evaluation of long‐term use of a portable oxygen concentrator capable of operating under car battery power

An oxygen concentrator that can be powered by a car battery was clinically evaluated. The oxygen concentrator was used on a 67‐year‐old man with sequelae of pulmonary tuberculosis who was receiving long‐term home oxygen therapy (HOT) after long‐term use of 4.7 years. His work required automobile trips over long distances. The equipment used was an adsorption‐type oxygen concentrator capable of operating on a DC 12 V power supply, which could be powered from a residential power outlet (AC 100 V) using a dedicated voltage converter. Using this equipment, he was capable of driving himself in comfort for 2 hours or longer, over a period of 4 years. Furthermore, it was possible to stay in a hotel during a trip, inhaling oxygen generated by the equipment. Hereafter, this equipment should enable or facilitate long‐distance driving, travel and lodging for HOT patients.

Effektivität von Sauerstoff-Demand-Systemen bei Patienten mit chronisch obstruktiver Atemwegserkrankung

To maintain mobility in patients with chronic hypoxemia who are under long-term oxygen therapy, portable oxygen systems are available. They have the disadvantage of a short range. To prolong the range and to reduce the cost of oxygen treatment, demand oxygen delivery systems (DODS) are used. Aim of the study was to compare three DODS (DOC-2000 [D], TransTracheal Inc.; Oxytron [O], Weinmann; Pulsair [P], DeVilbiss, Sunrise Medical) with continuous oxygen delivery. 17 patients (age 67.82 +/- 9.46 years; FEV1 1.23 +/- 0.69 l; PaO2 48.8 +/- 6.7 mm Hg) were studied. The continuous flow oxygen (CONT) and the DODS were applied to the patients for 30 minutes each in random sequence with an airflow of 2 l/min. After 15 and 30 minutes arterial blood gas analysis was done. Oxygen saturation was recorded continuously by pulseoximetry. After 15 minutes no significant differences in PaO2 were found between CONT and DODS. After 30 minutes no significant difference in PaO2 was found in CONT as compared to P. Significant lower PaO2 values were found for O and D as compared to CONT (p < 0.01). With P the range of a portable oxygen source was increased by 161.5 percent, with O by 172 percent, with D the range was increased by only 17.2 percent. Prolongation of range of a portable oxygen source can be achieved by means of DODS without a decrease of PaO2 and thus without loss of quality of the oxygen treatment. However, there are differences in efficacy between the DODS.

The Evaluation and Management of Hypoxemia in the Chronic Critically Ill Patient

Hypoxemia is a prevalent problem in the chronically critically ill patient. This article reviews the pathophysiologic mechanisms of hypoxemia in this patient population, discusses how oxygenation is evaluated, and reviews methods for delivery of oxygen. Other topics directly related to oxygen use, such as oxygen toxicity, heliox use, and portable oxygen devices, are included.

A newly developed “winterized” cart to carry portable oxygen cylinders for patients receiving home oxygen therapy

A newly developed “winterized” cart to carry portable oxygen cylinders for patients receiving home oxygen therapy

Randomized controlled trial of ambulatory oxygen and an ambulatory ventilator on endurance exercise in COPD

In a prospective, randomized study we examined the effect of (i) ambulatory oxygen and (ii) a portable, inspiratory pressure support (IPS) device on the endurance shuttle walk test (ESWT) in patients with severe chronic obstructive pulmonary disease (COPD). Ten outpatients [median (range) FEV10.60 l (0.35, 1.45)] performed the ESWT under five test conditions: baseline walk (no assistance), IPS at 14 cmH2O from a portable ventilator (the HIPPY, Friday Medical, U.K.), sham IPS (<8 cmH2O), ambulatory oxygen at 2 lmin−1, and sham oxygen (carrying the portable oxygen cylinder and breathing air). There were significant improvements in the ESWT with ambulatory oxygen, but a negative effect with the HIPPY device [mean (SD) time: baseline 172 (48) sec; oxygen 242 (62) sec; HIPPY 84 (35) sec]. The ESWT appeared sensitive to the effect of cylinder weight although differences in endurance capacity were not significant [sham oxygen 151 (45) sec]. The ESWT was sensitive to the acute application of oxygen, demonstrating a beneficial effect on endurance performance in patients with severe COPD. The ESWT could form the basis of a standardized assessment for ambulatory oxygen.

Skin hemodynamics during change from supine to lateral position.

The purpose of this study was to identify the skin hemodynamics during the position change from supine to lateral in patients with neurodegenerative diseases. The participants were 19 patients with neurodegenerative diseases and 12 healthy volunteers. The alteration in the total concentration of oxyhemoglobin and deoxyhemoglobin, indicative of change in blood volume, was measured in the skin of the left flank by using a portable noninvasive tissue oxygen monitor by near-infrared spectroscopy. The positions were changed from the left and right lateral with a return to the supine between each procedure. In healthy volunteers, total hemoglobin concentration (skin blood volume) increased when the position changed from supine to left lateral and decreased when changed from supine to right lateral. The decreased skin blood volume gradually recovered after a change from the supine to the right lateral position in healthy volunteers. However, it did not recover in three sporadic olivopontocerebellar atrophy (OPCA) patients with marked autonomic dysfunction and one Parkinsonian patient with severe orthostatic hypotension. Our study identified that the intracutaneous blood was changing dynamically during the position change from supine to lateral and was regulated by autonomic nerve function.

Reported Circuit Board Failures In Portable Oxygen Generator Lead to Field Correction

Reported Circuit Board Failures In Portable Oxygen Generator Lead to Field Correction

PHYSIOLOGICAL RESPONSES TO RECREATIONAL SNOWSHOEING

691 In recent years, the popularity of snowshoeing has increased due to innovations in snowshoe design; they are smaller, lighter, have maintenance-free aluminum frames, and a more versatile binding system. The purpose of this study was to provide descriptive data relative to exercise intensity when subjects snowshoed at a self-selected pace on both flat and variable terrain. Twenty volunteers (10M and 10FI aged 21-42 years participated in the study. Subjects snowshoed at a self-selected pace for 30 minutes on flat and variable terrain courses, in random order. Individual subjects were tested within a 2-3 day span so that conditions would be similar due to the possible effect that snow conditions and temperature may have had on the results. VO2 (ml/kg/min), HR (bpm), RPE, and caloric expenditure (Kcals/30 min) were measured during each trial. VO2 and Kcals were determined using the Aerosport KB1-C portable oxygen analyzer, HR was measured with a Polar HR watch, and RPE was assessed using the Borg (6-20) scale. (Table)TableIt was found that snowshoeing on the flat and variable courses elicited HR values equivalent to 75 and 84% of age-predicted maximal HR, respectively. The average RPE values of 13.7 and 15.1 indicate that subjects were working "somewhat hard" to "hard" on the two courses and the caloric expenditure values compare favorably to other common exercise modes. The results of this study indicate that snowshoeing at a self-selected pace continuously for 30 minutes provides sufficient intensity to increase cardiovascular endurance and positively alter body composition based on current ACSM guidelines.

Efectos de la oxigenoterapia líquida portátil sobre la deambulación

The effect on walking of portable liquid oxygen therapy (PLOT), which involves carrying a tank, remains unclear. Our aim was to evaluate the repercussion of PLOT on performance in the 6 minute walking test. We enrolled 30 patients receiving home oxygen therapy in a randomized crossover study, collecting data on arterial blood gases at baseline, spirometry, and performance on the 6 minute walking test at baseline and at later sessions with PLOT and with compressed air simulating oxygen. During the tests we measured peak heart rate, distance walked and time that oxygen saturation remained over 89%. For compressed air, no improvement over baseline values was observed for any of the parameters measured. During the PLOT tests, however, patients walked farther than at baseline and arterial oxygen saturation rose to the prescribed flow rate. Dyspnea was not significantly affected.

Do patients using long-term liquid oxygen differ from those on traditional treatment with oxygen concentrators and/or compressed gas cylinders? A comparison of two national registers

Long-term oxygen therapy (LTOT) in patients with chronic hypoxaemia is an expanding field. Traditional stationary oxygen, with and without portable compressed gas cylinders, and portable liquid oxygen equipment is available today. No official guidelines exist for the prescription of liquid oxygen vs traditional oxygen supply in LTOT, although it is generally thought that patients receiving liquid oxygen are younger and less seriously affected. The authors tested this hypothesis by comparing register data from two national Scandinavian registers of patients on LTOT in the same time period; one including all the patients on traditional oxygen treatment alone, e.g. concentrators and compressed gas cylinders ( n=1039), the other including all the patients using portable liquid oxygen alone ( n=117). About 80% of the patients in both groups suffered from chronic obstructive pulmonary disease. Younger patients were found in the liquid oxygen group ( P<0·004), but with clinically slightly worse blood gas derangement (mostly statistically significant). They had higher frequency of previous or present oedema ( P<0·0001), and there were more smokers in this group ( P<0·0001). No significant differences were seen with respect to sex distribution or oxygen delivery systems. Higher oxygen dose and longer daily oxygen treatment ( P<0·0001) were prescribed for the liquid oxygen patients compared with the patients on traditional oxygen with statistically higher oxygen tension during the prescribed treatment. A slight further increase in PaCO 2 was seen in both groups during oxygen treatment, of doubtful significance. Compared with patients on traditional oxygen, liquid oxygen thus appears to be prescribed for younger patients, independent of clinical status or blood gas levels.

Portable Oxygen Systems with PulseDose

Portable Oxygen Systems with PulseDose

Metalized Paint Chips Could Cause Short Circuit in Portable Oxygen Monitor

Metalized Paint Chips Could Cause Short Circuit in Portable Oxygen Monitor

Home Oxygen Therapy in Medicare Beneficiaries, 1991 and 1992

Obtain descriptive data on the use of home oxygen by Medicare beneficiaries and study the impact of certain demographic factors and diagnoses on oxygen use. A home oxygen user was defined as any Medicare beneficiary with at least one claim for home oxygen in the Health Care Financing Administration National Claims History 5% Physician Supplier Files for 1991 and 1992. Railroad board beneficiaries, health maintenance organization members, and those without continuous part B coverage were excluded. In 1991, there were 21,489 beneficiaries in the sample who received oxygen therapy. In 1992, there were 8,418 new users. Twenty-six percent of new users died in 1992. Factors significantly associated with death included age 76 years or older (relative risk [RR], 1.3), pneumonia (RR, 1.3), lung cancer (RR, 3.8), male gender (RR, 1.2), heart failure (RR, 1.3), and diagnoses suggestive of COPD (RR, 0.45). Seven percent of new users discontinued therapy within 1 month, 28% within 6 months. Liquid oxygen was used by 19% of current and 14% of new users. Factors significantly associated with liquid oxygen use included portable oxygen claims (odds ratio [OR], 2.4), nonmetropolitan residence (OR, 0.73), and white race (OR, 1.2). Descriptive information on patterns of home oxygen use, including associated medical conditions, types and duration of therapy, and survival is useful for regulatory purposes. This information supports concerns that current payment policy may discourage suppliers from providing liquid oxygen in underserved areas.

Portable Oxygen Units Could Read Inaccurate Quantity

Portable Oxygen Units Could Read Inaccurate Quantity

A solid polymer electrolyte-based oxygen sensor for portable oxygen meters

A solid polymer electrolyte-based oxygen sensor for portable oxygen meters

A laboratory assessment of oxygen delivery from a portable chemical generator.

A simple portable chemical oxygen generator was tested in the laboratory. The device is designed for use by the public as an oxygen supply until an emergency team arrives with appropriate oxygen cylinders. The generator was found to supply a mean (SD) flow of oxygen of 3.6 (0.01) l.min-1 for 12.5 (range 12.4-12.6)min. The mean (SD) total volume of oxygen produced was 47(0.17) l. The supplied oxygen mask was a variable performance type with the problems and limitations inherent in this design; an oxygen flow of 8 l.min-1 is required to provide 40% oxygen and most of the oxygen is wasted and not available to the patient. This poses a serious limitation to any device which has a limited capability (in flow and/or total volume) for producing oxygen.

Oxygen flow through nasal cannulae.

Since many operating theatres do not have distinct oxygen flowmeters, flow rates of oxygen were measured via nasal prongs at several settings and attachments to three anaesthetic machines. Oxygen-flow rates were measured using a Timeter RT-200 Calibration Analyzer at three, five and eight L.min-1 via nasal prongs attached to a distinct flowmeter, the common gas outlet (CGO) and the Y-piece of a circle system with the adjustable pressure release (APL) valve closed, open and partially open at circuit pressures of 10 and 20 cm H2O. The most accurate delivery of oxygen from a distinct flowmeter and the CGO (mean difference 0.2 +/- 0.2 and 0.4 +/- 0.4 respectively). Differences between the flowmeter and CGO were not significant (P = 0.1). Accuracy of flows via the Y-piece were worse than via the flowmeter and CGO (P < 0.0001). Flows via the Y-piece were less than those dialed, especially at high rates. With a partially open APL valve, flow depended upon pressure in the anaesthetic circuit, not upon the flow set. With the APL valve completely open, no flow occurred. To deliver supplemental oxygen in the operating theatre when there are no distinct flowmeters, nasal prongs should be attached to the CGO of the anaesthetic machine or a flowmeter on a portable E-tank oxygen cylinder. Connecting nasal prongs to the Y-piece of a circle system should be avoided since oxygen delivery is less than dialed, especially when the APL valve is open.

Oxigenoterapia portátil en la Comunidad de Madrid

Portable oxygen therapy using liquid oxygen has been available in the Madrid area since 1992 as part of a government program. The prescription of liquid oxygen theoretically requires the careful selection of patients who will benefit from a portable source of oxygen, as well as the performance of a series of treadmill tests with and without supplemental oxygen in order to assess the benefit derived from this expensive means of delivering therapy. As no studies had been done of whether these criteria for prescribing liquid oxygen were being met, we conducted telephone interviews with patients residing in the Madrid area who had portable oxygen sources at their disposal. Of a total of 190 patients, whose names were provided by oxygen supply companies, 145 could be evaluated. Liquid oxygen was not being used by 17%. Stress tests had not been performed before prescription of liquid oxygen in 65%. In conclusion, it can be suspected that a high percentage of patients receive liquid oxygen who do not meet the criteria for prescription and who have not performed the recommended tests, and that compliance is low.

Portable Hyperbaric Oxygen Therapy in the Emergency Department With the Modified Gamow Bag

Study objective: To compare oxygen administration by means of an inflatable portable hyperbaric chamber with that through a nonrebreather mask for the elimination of carboxyhemoglobin (COHb). Design: Double-crossover prospective analysis. Setting: University emergency department, Level I trauma center. Participants: Twelve healthy paid adult volunteers, all smokers. Interventions: Each subject smoked five cigarettes within 60 minutes. COHb levels were measured before and after smoking by means of cooximetry. Subjects then breathed hyperbaric and normobaric oxygen in separate trials for 40 minutes. Normobaric oxygen was administered through a nonrebreather face mask at 15 L/minute outside the Gamow bag. Hyperbaric oxygen was delivered inside the Gamow bag with a demand valve regulator mask at a pressure of 1.58 atmospheres absolute pressure (8.5 psi). Venous blood (.5 mL) was sampled every 5 minutes. The specimens were iced and assayed for COHb in triplicate. Results: A significant increase in the elimination of COHb was observed for each subject in the Gamow bag ( P<.05, repeated- measures ANOVA). The average half-life for COHb elimination was 27.5±1.08 minutes (mean±SE) (n=10). IV access failure occurred in two patients, with incomplete data as a result. Conclusion: The modified Gamow bag eliminated COHb more quickly than did nonrebreather mask oxygen and proved simple to operate and maintain. No complications were noted for any of the subjects. One subject experienced claustrophobia, but it abated after the bag was inflated. [Jay GD, Tetz DJ, Hartigan CF, Lane LL, Aghababian RV: Portable hyperbaric oxygen therapy in the emergency department with the Gamow bag. Ann Emerg Med December 1995;26:707-711.]

Comparison of oxygen uptake during a conventional treadmill test and the shuttle walking test in chronic airflow limitation

The purpose of this study was to investigate the relationship between performance on the shuttle walking test and maximal oxygen uptake (VO2max) during a conventional treadmill test in patients with chronic airflow limitation. Two different techniques were used to measure oxygen consumption, i.e. conventional Douglas bag techniques (treadmill test) and a portable oxygen consumption meter (shuttle test). Initially, 19 patients performed a shuttle walking test (after one practice walk) and a maximal treadmill walking test, in a randomized, balanced design. Subsequently, 10 patients, (after one practice) completed an unencumbered shuttle walking test and one supporting the portable oxygen consumption meter, in random order. The results of the first experiment revealed a strong relationship between performance during the shuttle walking test and VO2max during the treadmill walking test (r = 0.88). The results of the second experiment consistently demonstrated an incremental increase in oxygen consumption and ventilation in response to the increasing intensity of the shuttle walking test. Again, a strong relationship between VO2max and performance on the shuttle test was demonstrated (r = 0.81). We concluded that the shuttle walking test is a valid field exercise test of functional capacity. Performance on the test relates strongly to VO2max, the traditional indicator of cardiorespiratory capacity.