Disease management of COPD with pulmonary rehabilitation.

Pulmonary rehabilitation is a set of tools and disciplines that attends to the multiple needs of the COPD patient. It extends beyond standard care by addressing the disabling features of chronic and progressive lung disease. It centers on self-management, exercise, functional training, psychosocial skills, and contributes to the optimization of medical management. Exercise enables other components by building strength, endurance, confidence, and reducing dyspnea. Patients who have undergone rehabilitation often enjoy a reduced need for health-care utilization. On the downside, rehabilitation is a one-time intervention, the benefits of which dissolve over time. The patient's physician is rarely a participant in the program; thus, the physician is at a disadvantage in being able to support a long-term response. Rehabilitation is available to a small percentage of a large patient population who could benefit. Optimal disease management would entail redesigning standard medical care to integrate rehabilitative elements into a system of patient self-management and regular exercise. It should emphasize physician involvement in self-management, which is essential in developing and maintaining an effective exacerbation protocol. Pulmonary rehabilitation should take its place in the mainstream of disease management through its integrative and reconciliative role in the multidisciplinary continuum of services, as defined by the National Institutes of Health, Pulmonary Rehabilitation Research, Workshop of 1994.

Reversing disability of irreversible lung disease.

Pulmonary rehabilitation is a comprehensive multifaceted team approach for integrating medical management, coping skills, self-management techniques, and exercise reconditioning. It provides patients with chronic lung disease the ability to adapt and live full and nearly normal lives. These changes are possible because the overall disability includes significant reversible components: Patients have bronchospasm, infection, and cor pulmonale; they respond to progressively impaired lungs by progressive inactivity, leading to physical deconditioning. Both factors contribute to dyspnea. Because patients naturally fear dyspnea, they panic easily. During panic, their work of breathing may increase and respiratory failure may result. Pulmonary rehabilitation provides good medical management; provides exercises to increase strength, endurance, and tolerance to dyspnea; and trains patients in panic control. These programs have not been shown to lengthen life span or improve static lung function. They increase exercise performance and render patients functional, independent, and subject to fewer hospital admissions. Pulmonary rehabilitation is the only approach to chronic lung disease short of lung transplantation that improves the long-term outlook for these patients.

Long-term home oxygen therapy.

Oxygen therapy improves mortality and morbidity in hypoxemic patients with COPD. For best results, oxygen should be administered continuously. The general guidelines that qualify a patient for long-term home oxygen therapy are rather explicit, although there are some gray areas, such as increasing exercise performance in normoxemic COPD patients and the treatment of dyspnea in certain patients. The physiologic goals of oxygen therapy are to reverse or prevent tissue hypoxia under the various conditions of life. Patients often experience a fall in oxygen saturation during REM sleep and during exercise. Thus, the oxygen prescription should specify the oxygen setting during wakeful rest, sleep, and exertion. Pulmonary rehabilitation is the definitive long-term management for patients with chronic lung diseases by building endurance, strength, and coping skills. Patients undergoing pulmonary rehabilitation are taught to become active and mobile. The rehabilitation programs have a special role in helping patients to accept and properly administer their own oxygen therapy. Oxygen therapy should be based on mobility and portability. Improvements in the weight and bulk of oxygen containers and the introduction of oxygen-conserving devices have rendered oxygen systems more portable and less costly. The prescription initiates a clinical triad relationship between the patient, physician, and home oxygen vendor. Prescribing home oxygen is now more time-consuming, and the prescription process requires the careful attention of the physician. The prescription must include patient data, the diagnostic reasons for oxygen, the blood gases, the type of system, and the liter-flow for the various living conditions such as rest, sleep, and exertion. Reimbursement for oxygen via Medicare and other carriers will depend upon the physiologic data as well as the successful completion of a rather complex form. Oxygen therapy should be monitored by regular arterial blood gases or pulse oximetry where appropriate. Patients should have a blood gas sample taken upon any change of condition or adjustment of the oxygen flow setting. Successful oxygen therapy should be physician directed, based on a solid understanding of the physiologic processes involved.

Pulsed nasal and transtracheal oxygen delivery.

Oxygen conserving devices, the TTO catheters, electronic pulsed DODS and reservoir cannulas, increase efficacy of oxygen delivery; TTO also improves cosmetic appearance, comfort and compliance. We speculated that pulsing of oxygen transtracheally can increase efficiency of TTO. We modified the DODS to include settable delays and a rapid pre-inspiratory trigger. The first part of the study was performed with nasal oxygen on seven subjects and the second part, with TTO on 17 subjects. Nasal oxygen results indicate improved delivery efficiency with more rapid response. The TTO results indicate no significant change for each delay setting, but there was improvement in delivery efficiency when DODS was combined with TTO vs continuous flow TTO. Thus, early inspiratory delivery increases efficiency of oxygen therapy. Small delays in response time are critical in nasal delivery but not important in TTO. Pulsed TTO is more efficient than continuous flow TTO and merits long-term studies.

Demand oxygen delivery for patients with restrictive lung disease.

The demand oxygen delivery system has been reported to improve oxygen delivery 7:1 vs steady flow during rest and exercise in COPD patients. The present study evaluates the DODS during rest and exercise in eight patients with restrictive lung disease. It was concluded that the DODS provides substantial oxygen savings in RLD patients, particularly during exercise.

Inpatient pulmonary rehabilitation. A team approach to the more fragile patient.

Despite having fixed changes in lung structure, patients with chronic obstructive pulmonary disease and interstitial pulmonary fibrosis can be helped by pulmonary rehabilitation. They learn that shortness of breath is not to be feared but rather accepted and tolerated as a step toward eventual successful rehabilitation. They are taught to accept the reality of their disease but not to dwell on its limitations. They learn to fight depression and anxiety and to overcome their disability within a realistic framework. From the exercise program they build strength, endurance, and confidence and become more independent and mobile. Even very compromised patients can benefit from an intensive inpatient rehabilitation program.

A new pendant oxygen-conserving cannula which allows pursed lips breathing.

Multiple benefits of oxygen therapy for hypoxemic patients with chronic lung disease are well established. Steady flow oxygen therapy is inefficient, wasteful and has a high cost. The Oxymizer pendant improves efficiency of oxygen delivery compared with SF. However, the device requires that the patient inhale and exhale nasally to maximize its oxygen-saving properties. When patients do PLB they may not receive full oxygen-saving benefit of the pendant. Yet PLB itself can increase SaO2. We evaluated an AP, which does not require nasal exhalation, in nine patients with COPD. We measured SaO2 while breathing oxygen via SF and the AP with nasal-only breathing and PLB. Results indicate that the AP maintains an increase in SaO2 over SF during nasal-only breathing and a further increase during PLB. We conclude that AP acts as an oxygen conserver during PLB; PLB with the AP achieves greater savings than with nasal-only breathing.

Oxygen conservation and oxygen-conserving devices in chronic lung disease. A review.

The efficacy of long-term oxygen therapy for hypoxemic COPD patients is well established. However, oxygen is expensive and the portability of home oxygen is limited by the weight and bulk of the oxygen source. As a result, there has been a recent surge of interest in creating oxygen-conserving devices and methods. The efficiency of oxygen therapy can be improved over steady flow delivery by focusing oxygen delivery to early inspiration. Three methods for improving oxygen delivery efficiency--transtracheal catheter, reservoir cannula and demand-pulse oxygen delivery--are currently available for patient use. Each has its own set of advantages and disadvantages. By using oxygen conservation methods, the oxygen required to achieve adequate blood oxygenation can be reduced by a factor of 2:1 to 7:1 compared to steady flow. Thus, the cost of oxygen can be substantially reduced while increasing the portability and range of home oxygen therapy.

Demand oxygen delivery during exercise.

Nine hypoxemic patients with COLD, whose hypoxemia is aggravated by minimal exercise, volunteered for this study. Each subject underwent two treadmill exercise trials at two oxygen delivery settings, each on the DODS and SF delivery systems for a total of four exercise trials. We measured SaO2 via ear oximetry and recorded oxygen usage per minute. We compared the oxygen usage required for the two techniques to achieve an SaO2 of 90 percent. The results indicate that the mean oxygen requirement using the DODS to achieve an SaO2 of 90 percent was 211.4 ml/min as compared to SF delivery which required 1,610.9 ml/min. This implies an oxygen savings advantage of the DODS over SF of 7:1. The fact that the DODS oxygen savings extends to exercise conditions lends support to its use in portable oxygen therapy. Widespread use of this and other oxygen savings techniques could result in significant cost savings while maintaining the desired benefits of supplemental oxygen administration.

Pursed lips breathing training using ear oximetry.

Pursed lips breathing (PLB) training is often used in the management of patients with chronic obstructive lung disease (COLD). Previous clinical studies have demonstrated that PLB improves arterial oxygen saturation (SaO2) and CO2 removal as well as relieving dyspnea. Twelve hypoxemic subjects with stable COLD were randomly assigned to either the pursed lips (P) or control group consisting of general relaxation (R). The SaO2 was monitored via ear oximetry, and respiratory rate and tidal volume were monitored using a strain gage transducer and the minute volume was calculated. The PLB was taught by an experienced instructor using the ear oximeter as a monitoring display with a goal toward increasing SaO2. The subject was taught general relaxation (Rlx) with the aid of pleasant music. We compared PLB and Rlx treatments using an A-B-A crossover study design. In both groups, PLB significantly improved SaO2 over baseline (p less than 0.001) whereas Rlx did not. We conclude that patients can learn to increase their SaO2 by PLB using ear oximetry adjunctively.

Low-concentration oxygen therapy via a demand oxygen delivery system.

Recent heightened concern about the costs of medical care has stimulated research and development in devices and schemes for saving costs while retaining quality of care. Consistent with that concern is the fact that standard steady-flow oxygen delivery is so wasteful. Almost its entire benefit occurs at the very beginning of inspiration. We compared the efficacy of nasal oxygen delivery via a new demand oxygen delivery system (DODS) with the standard steady-flow (SF) method. The DODS incorporates a valve and sensor interposed between the oxygen reservoir and the patient, which meters oxygen to the patient only during early inspiration. Twelve COPD subjects with hypoxemia at rest received oxygen at flow settings of 1 to 4 L/min via SF and at various breath interval settings via the DODS method, calculated to match the above spectrum of the SF. We measured oxygen delivery using an ear oximeter. The results indicate that significantly less oxygen was required to provide equivalent saturations using the DODS compared with the SF method (p less than .001). The mean comparative savings in oxygen is better than seven to one favoring the DODS over the SF method. Further study is warranted, since the widespread use of such a device could result in substantial cost saving while increasing the range of portable oxygen delivery.

A new pendant storage oxygen-conserving nasal cannula.

With increasing interest in reducing the cost of oxygen therapy, we recently designed an oxygen-conserving cannula. It reduces the oxygen supply flow necessary to achieve adequate oxygen saturation, but because it requires the use of a reservoir situated under the nose, some patients find it obtrusive. We therefore designed a similar system but displaced the reservoir away from the face and onto the anterior chest wall where it could be hidden from view by the patient's clothing. We evaluated this pendant conserving nasal cannula (PNC) in seven hypoxemic patients with chronic obstructive pulmonary disease. We compared oxygen saturations achieved using the PNC vs the standard steady flow nasal cannula (SNC) at 0.5 through 4 L/min. The mean improvement in oxygen saturation using the PNC vs the SNC was 3.3 percent at 0.5 L/min, 4.3 percent at 1 L/min and 3.1 percent at 2 L/min. These differences were statistically significant (p less than 0.001). The saturation achieved by the PNC at 0.5 L/min was equivalent to that achieved by the SNC at 1.8 L/min. We conclude that the PNC provides effective oxygen delivery to patients at supply flows substantially less than the SNC. The device is aesthetically acceptable to patients and its widespread use in patients requiring chronic oxygen therapy could bring about significant financial savings.

Evaluation of a low-flow oxygen-conserving nasal cannula.

Oxygen therapy is one of the most frequently ordered therapies for patients with chronic obstructive pulmonary disease (COPD). In a large percentage of these cases, oxygen therapy is supplied via nasal cannula. With the rising cost of medical care and the search for more effective means of oxygen delivery, a new oxygen-conserving nasal cannula (CNC) that incorporates a closely coupled 20-ml reservoir was developed. Oxygen is stored in the reservoir during exhalation so that 20 ml of approximately 85% oxygen is the first gas inhaled. To test the hypothesis that the CNC is more efficient than the standard nasal cannula (SNC), 20 patients with COPD were evaluated. All patients were chronically hypoxemic at rest. Results indicate that when the CNC was compared with the SNC, arterial oxygen saturation levels were significantly different (p less than 0.001) at flow rates of 0.5, 1.0, and 2.0 L/min. Oxygen saturation were 2.9% higher at 0.5 L/min, 2.9% higher at 1 L/min, and 2.6% higher at 2 L/min for the CNC than for the SNC. In summary, the CNC offers a more efficient oxygen delivery system for those patients requiring supplemental oxygen administration by nasal cannula.