Home oxygen providers, physicians, and managed care organizations must work together to ensure that the benefits of LTOT remain both accessible and affordable, and RCPs play a key role in that success.

Since publication of the landmark Nocturnal Oxygen Therapy Trial¹ in 1980, home oxygen use has grown steadily. That study irrefutably demonstrated that “Long term oxygen therapy (LTOT) use improves both the length and quality of life of hypoxemic chronic obstructive pulmonary disease (COPD) patients.”² Growth has additionally been fueled by the trend to send patients home “quicker and sicker,” negating the once common practice of weaning patients from oxygen before discharging them to home. Guidelines for home oxygen prescriptions clarify the need for supplementary oxygen and ensure that the patients who need it, get it, while virtually eliminating abuses caused by providing unnecessary equipment to patients who will not benefit from it.

Indications
Supplementary home oxygen is indicated for any patient who presents with hypoxemia, which may be differentiated from hypoxia. “Hypoxia is a general term that means an inadequate availability of oxygen for cell function, whereas hypoxemia refers to a diminution in the actual content of oxygen in blood and implies tissue hypoxia but does not indicate what tissue or to what degree.”³ Hypoxemia can be either acute, as with pneumonia or postoperative atelectasis, or chronic, as with COPD or fibrotic lung disease.

The Centers for Medicare & Medicaid Services (CMS), formerly known as the Health Care Financing Administration (HCFA), provides guidelines for supplemental oxygen and sets the standard for nearly all adult oxygen prescriptions whether the patient has Medicare or a managed care (insurance) provider. Hypoxemia must be documented by a physician’s office or hospital, on room air, and must indicate a Pao2 of 55 torr or less, or Sao2 of 88% or less at rest. These patients are classified as Group I, making it permissible for the attending physician to prescribe the LTOT for up to 99 months (also known as “lifetime” in Medicare parlance). Documentation of the patient’s oxygen saturation can never be provided by a home oxygen company due to the obvious potential for conflict of interest.

The CMS specifically requires the documentation to be obtained on room air. Clinicians are sometimes surprised to learn that documenting an oxygen saturation of 87% while the patient is receiving 2 L of oxygen, for example, is unacceptable.

The Certificate of Medical Necessity (CMN), which home oxygen providers submit as documentation of patient need, also has provisions for documenting oxygen requirements “with sleep” or “with exercise.” It is important to note that home oxygen providers cannot be reimbursed for providing both a base (oxygen concentrator) and portable (E-cylinder outfit) to patients who qualify only under one of the latter two categories. They are reimbursed for providing only a portable oxygen system to patients who require oxygen only with exercise. And they are reimbursed for providing only a base system for patients who require oxygen only when sleeping.

The definition of exercise can lead to confusion when considering patients who may have relatively normal oxygen saturations at rest, but who desaturate rapidly when performing normal activities of daily living (ADL), such as walking across the room. These patients clearly require a continuous oxygen system, and their desaturation is not confined to exercise. In these instances, most clinicians consider saturations obtained while the patient performs routine, nonexertional activity, to fall into the “at rest” category. Conversely, saturations obtained during treadmill studies, for example, clearly fall into the “exercise” category. While these subtleties are sometimes lost on clinicians documenting the patient’s oxygen needs, and physicians who complete the CMNs, they are essential to home oxygen providers who must choose an appropriate oxygen delivery system and obtain reimbursement for the services most appropriate to the patient’s needs.

There is an exception to the requirement for oxygen saturations to be 88% or less, permitting saturations of 89% or less for patients presenting with very specific clinical conditions (cor pulmonale, congestive heart failure, or erythrocythemia with a hematocrit >56). These patients are categorized as Group II, and require recertification (via a new ABG [arterial blood gas] or pulse oximetry test) between the 61st and 90th day following the initial prescription date.

Children and infants typically require home oxygen resulting from clinical scenarios that are substantially different from adults. This, coupled with the fact that their oxygen requirements and goals of therapy may be more patient-specific, has thus far enabled physicians to prescribe home oxygen for pediatric patients with more latitude than for adults. Frequent titration of oxygen liter flows in infants is essential, requiring clinicians to use “...the lowest possible oxygen flow needed to maintain normoxia in infants requiring prolonged oxygen therapy via nasal cannula.”⁴

Modality
Home oxygen systems allow delivery of both low flow oxygen via nasal cannula or transtracheal oxygen catheter, and high flow oxygen via trache collar, aerosol mask, or facemask. There are three modes of delivery; each has relative merits and requires an experienced clinician to match the advantages of the system to the needs of the patient.

Oxygen concentrators are electrically powered and use a compressor to force room air through a sieve bed, which separates oxygen and nitrogen molecules from room air based on size and polarity. These can achieve an oxygen concentration of 90%-95%, and deliver flows of up to 5 or 6 L/min. When the patient requires portable oxygen for use outside the home, a supplemental system must be provided. Advantages of oxygen concentrators include economy, convenience, and a high rate of dependability. Disadvantages include noise generation, power consumption, and the inability to function during a power outage. A compressed gas backup system is normally provided for patients who require continuous oxygen use. In the event of a power outage, the patient’s portable oxygen system often serves as an appropriate backup system.

Liquid oxygen systems utilize cryogenic technology to store oxygen at minus 297° F. Because 1 L of liquid oxygen is equal to 840 L of gaseous oxygen, a large quantity of oxygen can be contained in a small receptacle. These systems provide a stationary base unit, which is refilled at regular intervals, and a lightweight portable unit that can be refilled from the base. Home oxygen suppliers often help offset the considerable labor costs of refilling the liquid oxygen base units by providing (at no additional charge) an oxygen concentrator for use when the patient is home. This practice invariably reduces the frequency of liquid oxygen refills. Advantages include silent operation (saving the occasional hiss of a pop-off valve), and the convenience of a refillable, lightweight portable tank.

The Money Crunch
CMS applies a “modality neutral” method of oxygen reimbursement, which applies the same fixed payment regardless of the mode of delivery (compressed gas, concentrator, and liquid system); however, the costs of supplying various systems can vary considerably.

Because the fixed-rate reimbursement is all inclusive, there are no additional payments for supplies or home visits by an RCP. Transtracheal oxygen (TTo2) catheters are an excellent example of an underutilized technology resulting from this situation. The fact that oxygen suppliers must provide the specialized tubing and catheter replacements every 90 days without additional compensation may discourage them from proactively assessing patients and recommending the technology to the physicians of appropriate patients.

In 1997, HCFA cut reimbursement of LTOT by 30% based on an assessment of LTOT reimbursement in Department of Veterans Affairs (VA) hospitals and additional cuts followed. Most experts agreed the comparison was of questionable validity because “VA hospitals’ costs are lower because of arbitrary limits on the kinds of systems provided, regardless of patient need. Most VA hospitals simply provide an oxygen concentrator and a small number of wheeled high pressure oxygen tanks (usually E-cylinders).”² In addition, the cost assessment did not consider costs for regulators, tubing, and cannula. “The reimbursement reduction is causing some suppliers to restrict the use of ambulatory oxygen systems in the private sector, even though they are medically necessary and prescribed by physicians.”²

Competitive bidding experiments, for example, increasingly reward oxygen providers for cutting costs at all cost, while offering only lip service to the concepts of customer service and quality of life. “Many patients who once enjoyed monthly visits by RCPs are now only visited quarterly (or less often), and at times by nonclinicians. Further cuts in equipment reimbursement via competitive bidding, application of inherent reasonableness, and other reductions in equipment reimbursement are currently being considered and proposed.”⁵ If some of these proposals are implemented, “the impact on patient care, patient safety and patient outcomes would be devastating.”⁵

When oxygen reimbursement is cut dramatically, it becomes increasingly problematic to provide quality service to patients who live in remote areas, or to patients who would benefit from oxygen delivery modalities they perceive as being more expensive, such as liquid oxygen or TTo2 catheters.

Consequently, physicians may need to carefully specify the most appropriate home oxygen delivery system if the patient is to be optimally served. Meanwhile, oxygen providers may be pressured into diminishing services and downsizing clinical staff when reimbursement has been calculated on an unrealistic model.

Recertification
Studies have documented that at one time, up to 60% of patients receiving home oxygen therapy could have potentially been discontinued from oxygen if properly evaluated. Physicians who prescribed home oxygen were sometimes lax in reevaluating patients’ conditions, and although home oxygen providers sometimes asked physicians to reevaluate patients’ conditions with the intent to discontinue oxygen service, there was a financial disincentive to do so.⁶ The Fifth Oxygen Consensus Conference recommended that patients receiving LTOT be reevaluated within 90 days of discharge to home, and that recommendation is in the process of being implemented by the CMS. The conference further suggested, “If an ongoing need for LTOT is determined at the 90-day retesting, then additional arterial blood gas or saturation measurements are unnecessary.”²

In most cases, the documentation can and should be part of routine follow-up visits that are essential to comprehensive management of chronic disease; however, CMS has not made entirely adequate provisions for recertifying patients by providing reasonable compensation and convenient access to retesting. When a physician’s office cannot provide overnight oximetry, for example, the only alternative may be to admit the patient into a hospital to conduct the testing.

The American Association for Respiratory Care has urged consideration of the following recommendations⁷:

1. Medicare should provide options for retesting in order to ensure uninterrupted patient access to medically necessary home oxygen.

2. Medicare should establish coverage of and reimbursement for pulse oximetry in all care settings.

3. Medicare should provide fair compensation for pulse oximetry.

4. Medicare should ensure appropriate oversight of home oxygen patients in the recertification process.

“To enable patients to comply with recertification requirements [CMS] must properly establish a retesting mechanism that includes coverage of and reimbursement for pulse oximetry in all settings, including the patient’s home. This coverage would be especially helpful to home oxygen patients in rural, urban, and other underserved areas. Patients depend on these options.”⁷

Planes, Trains, and Winnebagos
Many home oxygen providers agree that part of their service to patients includes providing appropriate oxygen systems for use during extended travel within the 48 states. Providing oxygen aboard cruise ships, trains, and bus lines is usually in joint agreement between the oxygen provider and the patient. The oxygen provider almost never absorbs the costs of providing oxygen for trips abroad. Kari Fritz, RRT, a consultant for Banner Health Systems, says, “There’s a lot more CMS could do to facilitate travel [for patients who require oxygen].”

Air travel can be problematic as CMS does not provide for reimbursement for the cost of in-flight oxygen. Travel regulations prohibit patients from using their own oxygen systems on board, and there is substantial variability in the availability of in-flight oxygen by the airlines. Most airlines require patients to make in-flight oxygen arrangements 2 to 7 days ahead of time, and a copy of the prescription is normally required.

In some cases, in-flight oxygen is not available except for emergencies, and, in others, there may be no ability to specify the appropriate liter flow. Typically, airline charges for providing in-flight oxygen are approximately $75 for each leg of the trip. This can add $300 to the cost of a round-trip flight that includes a single connecting flight, making air travel all but impossible for individuals of limited means.

The Fifth Oxygen Consensus Conference stated, “…patients have a right to medically necessary oxygen during air travel. The airline industry should develop and promote industry guidelines regarding provision of and pricing of supplementary oxygen during air travel.”²

Conclusion
The benefits of home oxygen for patients who need it are well documented, and the United States arguably surpasses any other nation in the ability to deliver innovative, high-quality products, and affordable home oxygen services to its citizens. The opportunity to be discharged from the hospital more quickly with the benefit of home oxygen enhances quality of life, while reducing overall health care costs. As managed care guidelines for home oxygen use evolve, RCPs have a greater responsibility than ever before to recognize the challenges and opportunities presented by the growing needs and limited resources.

John A. Wolfe, RRT, is a contributing writer for RT Magazine.

References
1. Nocturnal Oxygen Therapy Trial Group. Continuous or nocturnal oxygen therapy in hypoxemic chronic obstructive lung disease: a clinical trial. Ann Intern Med. 1980;93:391-398.
2. Petty TL, Casaburi R. Recommendations of the Fifth Oxygen Consensus Conference. Respir Care. 2000;45:957-961.
3. Egan DF. Fundamentals of Respiratory Therapy. St Louis: CV Mosby Co; 1977:182-183.
4. Kuluz JW, McLaughlin GE, Gelman B, et al. The fraction of inspired oxygen in infants receiving oxygen via nasal cannula often exceeds safe levels. Respir Care. 2001;46:897-901.
5. Spratt G, Petty TL. Partnering for optimal respiratory home care: physicians working with respiratory therapists to optimally meet respiratory home care needs. Respir Care. 2001;46:475-485.
6. Oba Y, Salzman GA, Willsie SK. Reevaluation of continuous oxygen therapy after initial prescription in patients with chronic obstructive pulmonary disease. Respir Care. 2000;45:401-406.
7. AARC comments submitted to HCFA regarding the transmittals on February 15, 2001. Members contact Jill Eicher, AARC Director of Government Affairs.