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Guide to Prescribing Home Oxygen

by Thomas L. Petty, M.D.


The Key to Prescibing Home Oxygen


Keys to Successful Treatment

Home Oxygen Options

Conserving Device Technology

Costs and Reimbursement

Patient Considerations in Selecting Equipment

About Thomas L. Petty, M. D.



Home Oxygen Options

Patient Interfaces

There are several patient interface options available. Each has an appropriate use.

Device Flow* FIO2 Range Appropriate Use
Nasal Cannula 1/4-8 LPM 22-45% Long-term oxygen therapy (LTOT) patients
Transtracheal Catheter 1/4-4 LPM 22-45% Patients who don't accept cannulas, high flow requirements
Reservoir Cannula 1/4-4 LPM 22-35% LTOT patients
Simple Mask 6-12 LPM 35-50% Acute short-term therapy requiring moderate FIO2
Reservoir Mask 6-10 LPM 35-60% Emergencies, acute hypoxemia, moderate FIO2
Nonrebreather Mask 10-15 LPM 80-100% Emergencies, respiratory failure

* Liter Flow and FIO^ are reflective of continuous flow only.
+ Device yields arterial oxygen saturation equivalent to an inhalant in this FIO: range.

Types of Home Oxygen Systems

There are three basic home oxygen delivery systems that can be used in various combinations to meet your patient's needs. They are oxygen concentrators, liquid oxygen units and high-pressure cylinders.

Oxygen concentrator device

Oxygen Concentrator

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.

Base unit of liquid oxygen

Liquid Oxygen

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 -297F 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.

Persoanl liquid oxygen system

New on the scene is the personal liquid oxygen system, a way of using liquid oxygen that can enhance patient mobility and fitness. Comprised of a small and lightweight portable component that is worn by the patient and a proprietary, high-capacity, no-loss reservoir for refilling, the personal liquid oxygen system is more affordable and convenient for active patients than the other oxygen modalities. Duration of the portable is approximately 10 hours at a flow setting of two* The portable unit may be connected to the reservoir for continued breathing during sleep. Oxygen deliveries for the reservoir are as few as eight per year.



High pressure oxygen system

High Pressure Systems

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.

Following are descriptions of the commonly used combinations of oxygen systems:
Oxygen Concentrator, E Cylinder and Cart

Combination 1
Oxygen Concentrator, E Cylinder and Cart with Standard Flow Regulator

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.

Oxygen Concentrator and M6 or M9 Cylinder with Conserving Regulator

Combination 2
Oxygen Concentrator and M6 or M9 Cylinder with Conserving Regulator

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.

Oxygen Concentrator, Liquid Oxygen Stationary and Liquid Oxygen Portable (Combo System)

Combination 3
Oxygen Concentrator, Liquid Oxygen Stationary and Liquid Oxygen Portable (Combo System)

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.

Liquid oxygen stationary and portable

Combination 4
Liquid Oxygen Stationary and Portable

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.

Liquid Oxygen Stationary, and Liquid Portable with Demand Conserving Device

Combination 5
Liquid Oxygen Stationary, and Liquid Portable with Demand Conserving Device

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.

Personal Liquid Oxygen System, Portable Unit and Reservoir

Combination 6
Personal Liquid Oxygen System, Portable Unit and Reservoir

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.

TABLE 3 Advantages and Disadvantages of Available Home Oxygen Systems
Accommodates Activity Easy To Operate Quiet Operation
Combination 1 C>2 Concentrator and standard flow regulator Adequate Average Average
Combination 2 C>2 concentrator, M6 or M9 cylinder with conserving device Above Average Average Average
Combination 3 Combo system: 0^ concentrator, conventional liquid stationary and portable Above Average Above Average Average
Combination 4 Conventional liquid oxygen stationary and portable Above Average Excellent Excellent
Combination 5 Conventional liquid oxygen stationary, portable and conserving device Excellent Above Average Excellent
Combination 6 Personal liquid oxygen system Excellent Excellent Excellent