Oxygen concentrators.

This study focuses on molecular-sieve concentrators that deliver high-content oxygen for continuous, long-term therapy, which improves and extends the quality of life for adult patients who suffer from such illnesses as chronic obstructive pulmonary disease. We did not include membrane concentrators, which produce a maximum concentration of 40% oxygen (compared with 90% or more for molecular-sieve concentrators), because they are not suitable for most long-term oxygen-therapy applications. Although oxygen concentrators are most often used at home, they are also occasionally used in hospitals or nursing homes as an economical method of delivering oxygen when built-in systems are not required or available. We evaluated 10 oxygen concentrators from nine manufacturers. All of the units are similar in general design and appearance, except for one 3 L/min capacity unit that is smaller and lighter than the other 4 or 5 L/min units. Our ratings and rankings are based primarily on the availability of an oxygen concentrator status indicator that meets our criteria, as well as on electrical safety and maintenance issues. Nine units are rated Acceptable; one unit is rated Conditionally Acceptable because it poses an electrical safety hazard. Readers are cautioned not to base purchasing decisions on our ratings alone, but on a thorough understanding of all issues surrounding the use of oxygen concentrators, which can be gained only by reading this study in its entirety. In the Discussion section, "Issues in Selecting, Purchasing, and Using Oxygen Concentrators," we discuss important factors to consider, such as required flow, oxygen concentration status indicators, high-temperature performance, electrical safety, noise, maintenance, and cost. Manufacturers' specifications for these and other units are available in ECRI's Hospital Product Comparison System.