A concentrator is a device that separates oxygen from room air.
It is small, reliable and relatively inexpensive. A hidden cost is
the electricity that is consumed during its operation, which is not
normally reimbursable and may cost the patient thirty dollars or
more a month. The concentrator is not an ambulatory product. It
stays in the room in which it is placed, and patients use different
lengths of oxygen tubing to move around. Maximum flow rate is
normally 5 to 6 LPM.

Vessels for conventional liquid oxygen are highly efficient means
of transporting oxygen. One liter of liquid oxygen equals 860
gaseous liters. Liquid oxygen is approximately -297�F and when kept
under pressure of 18 to 22 psi will remain in a liquid state. Liquid
oxygen is delivered to the patient’s home in a base unit that can be
the primary source of oxygen while at home and can be used to fill a
smaller portable unit when the patient leaves home. Conventional
liquid oxygen vessels require no power source to operate, making it
an appropriate choice for patients in areas with frequent power
outages. Conventional liquid oxygen systems are quiet and have no
major moving parts. When the conventional liquid oxygen base unit is
used as the primary oxygen source, it needs to be refilled
approximately every two weeks, depending on the patient’s
consumption rate and liter flow.

*(16BPM1;3IE)

Thirty years ago a cylinder and regulator were the standard for
patients who were receiving home oxygen therapy. When it is the only
source of oxygen, patients require that two or three large cylinders
be delivered once weekly. These units are very heavy and should only
be handled by the oxygen provider. Today, cylinders of varying sizes
are used as backup systems and for use when the patient H-cylinder
travels outside the home. Oxygen conservers with small aluminum
cylinders are currently used as an alternative to small liquid
oxygen vessels to provide for moderate ambulation when concentrators
are used in the home.

Often referred to as the “standard oxygen setup,” this is the
most common modality combination used to deliver home oxygen. The
oxygen concentrator can deliver oxygen with 50 feet of oxygen
tubing. However, because the patient must stay close to the
concentrator, it is not a good method for patients who are very
active outside the home. An E cylinder pulled in a cart may be used
when the patient leaves home, but E cylinders are cumbersome to
handle and maneuver for many patients. Often, providers allow the E
cylinders to serve as backup in the event of a power outage. One E
cylinder running at 2 LPM will last approximately five hours. When
used with a conserver, duration can be 15 hours or more.

When a concentrator is used in conjunction with a smaller,
lighter cylinder, such as an M6 or M9 with a conserving device, the
patient is able to easily leave the house for most activities.
Conserving devices fit most sizes of high pressure cylinders and
regulate the flow of oxygen so that less is wasted, thereby making
the cylinder last longer. Patients are still required to store
cylinders and must know how to change a regulator. Most conservers
extend use time 2 to 4 times that of continuous flow. Refer to page
7 for more information on conserving devices.

The combo system is intended for the highly ambulatory patient.
This oxygen modality provides a concentrator for use within the home
and a liquid stationary and portable unit for use away from home.
The exclusive purpose of the liquid stationary is to fill the liquid
portable system and is not used while the patient is home unless
there is a power failure. The stationary liquid unit serves two
purposes: to fill the liquid portable and as a backup unit in the
event of a power failure. The liquid oxygen system allows patients
to fill a portable unit at will and keeps them from having to store
and handle cylinders. Using a concentrator in conjunction with the
liquid system also reduces the frequency of deliveries required to
refill the liquid system.

This traditional liquid oxygen setup is still used today. There
is less equipment for patients to operate since they use the
stationary unit for at-home use, and they have the ability to fill
their portable when they desire. Patients using this combination are
visited every 7 to 11 days so the stationary system can be refilled.

Pneumatic conserving devices require no batteries and allow the
liquid stationary system to last twice as long as without the
device. This substantially reduces the number of trips to the
patient’s home for refill. This cost reduction, together with the
savings realized by not purchasing a concentrator, makes this a good
choice for very active patients. The conserver can be clipped to
anything close to the patient and permits patient movement up to 100
feet from the base unit. Conserving devices added to an existing
stationary and portable combination may not be covered under
Medicare allowables.

The personal liquid oxygen system is a modality that has brought
recent change to home oxygen therapy and is appropriate for patients
with a more active lifestyle. It is a single-device, low-cost oxygen
therapy option that can be used 24 hours a day. Patient compliance
and outcomes may be improved by its small size, portability and
long-lasting duration. The portable unit worn by the patient is
filled from the reservoir and can be connected to it during sleep or
rest.