Cardiopulmonary Rehabilitation



Cardiopulmonary Rehabilitation


Kenneth A. Wyka




Steady improvements in acute care are presenting new medical and social problems. As more patients survive acute illnesses, there are increasing numbers of individuals with chronic disorders. These chronic disorders are associated with a wide spectrum of physiologic, psychologic, and social disabilities. Foremost among these individuals with chronic disorders are individuals with chronic cardiopulmonary disease. Chronic obstructive pulmonary disease (COPD) is expected to be the third leading cause of death in the United States by 2020.1


Although differences in diagnoses can have an impact on treatment outcomes and survival, patients with chronic pulmonary disorders have much in common. All of these patients have difficulty coping with the physiologic limitations of their diseases, and these physiologic limitations result in many psychosocial problems. The end result often is an unsatisfactory quality of life. The high incidence of repeated hospitalizations and the progressive disability of these patients require well-organized programs of rehabilitative care. This chapter provides foundational knowledge regarding the goals, methods, and issues involved in providing planned programs of rehabilitation for individuals with chronic pulmonary disorders.



Definitions and Goals


The Council on Rehabilitation defines rehabilitation as “the restoration of the individual to the fullest medical, mental, emotional, social, and vocational potential of which he or she is capable.”2 The overall goal is to maximize functional ability and to minimize the impact the disability has on the individual, the family, and the community. Pulmonary rehabilitation is the “art of medical practice wherein an individually tailored, multidisciplinary program is formulated, which through accurate diagnosis, therapy, emotional support, and education stabilizes or reverses both the physio- and psychopathology of pulmonary diseases and attempts to return the patient to the highest possible functional capacity allowed by his or her pulmonary handicap and overall life situation.”3


The general goals of pulmonary rehabilitation are to control and alleviate symptoms, restore functional capabilities as much as possible, and improve quality of life.4 Pulmonary rehabilitation does not reverse or stop progression of the disease, but it can improve a patient’s overall quality of life. Health care providers from various disciplines are needed to reach these goals.



Historical Perspective


Pulmonary rehabilitation is not a new concept. In 1952, Barach and colleagues5 recommended reconditioning programs for patients with chronic lung disease to help improve their ability to walk without dyspnea. Decades passed before clinicians paid any attention to this concept. Instead of having their patients participate in reconditioning programs, most physicians simply prescribed oxygen (O2) therapy and bed rest. The result was a vicious cycle of skeletal muscle deterioration, progressive weakness and fatigue, and increasing levels of dyspnea including at rest. Patients became homebound, then room-bound, and eventually bed-bound. Improved avenues of therapy and rehabilitation were needed.


In 1962, Pierce and associates6 published results confirming Barach’s insight into the value of reconditioning. They observed that patients with COPD who participated in physical reconditioning exhibited lower pulse rates, respiratory rates, minute volumes, and carbon dioxide (CO2) production during exercise. However, they also found that these benefits occurred without significant changes in pulmonary function. Soon thereafter, Paez and associates7 showed that reconditioning could improve both the efficiency of motion and O2 use in patients with COPD. Subsequently, Christie8 showed that the benefits of reconditioning could be achieved on an outpatient basis with minimal supervision. Since Christie’s work in 1968, other investigators have continued to research the benefits of pulmonary rehabilitation.


The available evidence at the present time consistently indicates that pulmonary rehabilitation benefits patients with chronic obstructive and restrictive pulmonary disease.9-12 When combined with smoking cessation, optimization of blood gases, and proper medication use, pulmonary rehabilitation offers the best treatment option for patients with symptomatic pulmonary disease. Programs for pulmonary rehabilitation must be founded on the sound application of current knowledge in the clinical and social sciences. In fall 2006, the American College of Chest Physicians (ACCP) and the American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR) released their evidence-based guidelines relating to pulmonary rehabilitation aimed at improving the way pulmonary rehabilitation programs are designed, implemented, and evaluated through patient outcomes.13



Scientific Basis


Rehabilitation must focus on the patient as a whole and not solely on the underlying disease. For this reason, effective pulmonary rehabilitation programs combine knowledge from both the clinical and the social sciences. Knowledge from the clinical sciences can help quantify the degree of physiologic impairment and establish outcome expectations for reconditioning. Application of the social sciences is helpful in determining the psychological, social, and vocational impact of the disability on the patient and family and in establishing ways to improve the patient’s quality of life.



Physical Reconditioning


At rest, an individual maintains homeostasis by balancing external, internal, and cellular respiration. Physical activity, such as exercise, increases energy demands. To maintain homeostasis during exercise, the cardiorespiratory system must keep pace. Figure 50-1 shows how the body responds to exercise. Ventilation and circulation increase to supply tissues and cells with additional O2 and to eliminate the higher levels of CO2 produced by metabolism.



As depicted in Figure 50-2, O2 consumption and CO2 production also increase in linear fashion as exercise intensity increases. If the body cannot deliver sufficient O2 to meet the demands of energy metabolism, blood lactate levels increase above normal. In exercise physiology, this point is called the onset of blood lactate accumulation (OBLA). As this excess lactic acid is buffered, CO2 levels increase, and the stimulus to breathe increases. The result is an abrupt upswing in both CO2 and image (referred to as the ventilatory threshold). Beyond this point, metabolism becomes anaerobic, the efficiency of energy production decreases, lactic acid accumulates, and fatigue sets in.




Patients with COPD who lack adequate pulmonary function have severe limitations to their exercise capabilities. Their high rate of CO2 production during exercise results in respiratory acidosis and a shortness of breath out of proportion to the level of activity. In addition, as ventilation increases, the rate of O2 consumption in a patient with COPD increases significantly (Figure 50-3). Together, these factors limit patient tolerance for any significant increase in physical activity.



Pulmonary rehabilitation must include efforts to recondition patients physically and increase their exercise tolerance. Reconditioning involves strengthening essential muscle groups, improving overall O2 use, and enhancing the body’s cardiovascular response to physical activity (Box 50-1).




Psychosocial Support


If the overall goal of pulmonary rehabilitation is to improve the quality of patients’ lives, physical reconditioning alone is insufficient. Psychosocial indicators generally are good predictors of morbidity in patients with COPD. Studies show that the relative success of reconditioning plays less of a role in determining whether patients complete a program than meeting their psychosocial support needs.14


There is a well-established relationship between physical, mental, and social well-being in humans. Everyday life is full of such relationships, such as the physical fatigue that follows a period of emotional tension. Many of these associations are part of normal human behavior. However, emotional states such as stress can cause or aggravate an existing physical problem. Likewise, physical manifestations of disease, such as recurrent dyspnea, can worsen stress.


The progressive nature of COPD can negatively affect the patient’s overall outlook on his or her disease and reduce motivation to adapt to its consequences. The best medical care available can be negated, and a patient can experience a progressively downhill course because of an unfavorable mental state. Patients with COPD often have a tendency to develop severe anxiety, hostility, and stress as a direct consequence of their disability. Because patients are fearful of economic loss and death, they can develop hostility toward the disease and often toward the people around them.


In terms of social function, the physiologic impairment of chronic lung disease combined with other variables can severely restrict a patient’s ability to perform routine tasks requiring physical exertion. Intolerance for physical exertion lessens patients’ social activity. More important, however, is patients’ potential loss of confidence in their ability to care for themselves that can accompany such impairments, followed by resultant loss of feelings of dignity and self-worth.


Figure 50-4 presents elements of how chronic lung disease and other variables can have an impact on a patient’s quality of life. It is here that the link between the physical reconditioning and psychosocial support components of rehabilitation becomes most evident. By reducing exercise intolerance and enhancing the body’s cardiovascular response to physical activity, patients can develop a more independent and active lifestyle. For some patients, simply being able to walk to the market or play with their grandchildren can contribute to a greater feeling of social importance and self-worth. For others, physical conditioning may allow a return to near-normal levels of activity, including vocational pursuits.



Many patients disabled with pulmonary disease are in their economically productive years and are anxious to return to economic self-sufficiency. For these patients, occupational retraining and job placement are key ingredients in a good rehabilitation program. An occupational therapist can play a vital role here and should be included, if possible, as a member of the interdisciplinary rehabilitation team and in the pulmonary rehabilitation program. The pulmonary rehabilitation program should be based on the individual needs and expectations of each patient. Each patient’s physical ability and his or her education, past experience, aptitude, and personality should be considered. Evaluation and placement of the rehabilitation patient require the skills of vocational counselors and occupational therapists and the cooperation of business and industry.



Structure of A Pulmonary Rehabilitation Program


Program Goals and Objectives


Pulmonary rehabilitation programs vary in their design and implementation but generally share common goals. Examples of these common goals are listed in Box 50-2. These general goals assist planners in formulating more specific program objectives. When determining objectives, both patients and members of the rehabilitation team should have input. These objectives should always be stated in measurable terms because this helps facilitate the determination of both patient outcomes and the therapeutic success and value of pulmonary rehabilitation. Depending on the specific needs of the participants, program objectives can include the following:




When program objectives are specifically defined and structured in a measurable way, strategies can be tailored to ensure the maximum results and benefit. Demonstration of program effectiveness also becomes easier and more acceptable by the medical community. However, benefits realized by participating patients are not always easy to identify and may be controversial.



Patient Evaluation and Selection


Before beginning a pulmonary rehabilitation program, clinicians need to define and establish criteria for entry or selection. Patient selection requires comprehensive evaluation and testing.



Patient Evaluation


Pulmonary rehabilitation programs must have a qualified medical director, usually a pulmonologist, to provide overall medical direction of the program and to screen prospective patients.17 Patient evaluation begins with a complete patient history—medical, psychologic, vocational, and social. A well-designed patient questionnaire and interview form assist with this step. The patient history should be followed by a complete physical examination (see Chapter 15). A recent chest film, resting electrocardiogram (ECG), complete blood count, serum electrolytes, and urinalysis provide additional information on the patient’s current medical status (see Chapter 16).


To determine the patient’s cardiopulmonary status and exercise capacity, both pulmonary function testing and a cardiopulmonary exercise evaluation may be performed. Pulmonary function testing includes assessment of pulmonary ventilation, lung volume determinations, diffusing capacity (DLCO), and spirometry before and after bronchodilator use (see Chapter 19).


The cardiopulmonary exercise evaluation serves two key purposes in pulmonary rehabilitation. First, it quantifies the patient’s initial exercise capacity. This quantification provides the basis for the exercise prescription (including setting a target heart rate) and yields the baseline data for assessing a patient’s progress over time. In addition, the evaluation helps determine the degree of hypoxemia or desaturation that can occur with exercise; this provides the objective basis for titrating O2 therapy during the exercise program. To guide practitioners in implementing exercise evaluation, the American Association for Respiratory Care (AARC) has published clinical practice guidelines on exercise testing for evaluation of hypoxemia or desaturation or both18 and pulmonary rehabilitation. Excerpts from these guidelines appear in Clinical Practice Guidelines 50-1 and 50-2.19



50-1


Exercise Testing for Evaluation of Hypoxemia, Desaturation, or Both


AARC Clinical Practice Guideline (Excerpts)*




Contraindications


Absolute contraindications include the following:



Relative contraindications to exercise testing include the following:




Precautions and Possible Complications


Indications for ending testing include the following:



Abnormal responses that may require discontinuation of exercise include (1) increase in systolic blood pressure to >250 mm Hg or diastolic pressure to >120 mm Hg, (2) increase in systolic pressure of >20 mm Hg from resting level, (3) mental confusion or headache, (4) cyanosis, (5) nausea or vomiting, (6) muscle cramping.





*For the complete guidelines, see American Association for Respiratory Care: AARC clinical practice guideline: exercise testing for evaluation of hypoxemia and/or desaturation. Respir Care 46:514, 2001.


Refer to the Modified Borg Dyspnea Scale (immediately following).



50-2   Pulmonary Rehabilitation


AARC Clinical Practice Guideline (Excerpts)*









*For the complete guidelines, see American Association for Respiratory Care: AARC clinical practice guideline: pulmonary rehabilitation. Respir Care 47:617, 2002.



The exercise evaluation procedure involves serial or continuous measurements of several physiologic parameters during various graded levels of exercise on either an ergometer or a treadmill (Box 50-3). To allow for steady-state equilibration, these graded levels are usually spaced at 3-minute intervals. Work levels are increased progressively until either (1) the patient cannot tolerate a higher level or (2) an abnormal or hazardous response occurs.


Jun 12, 2016 | Posted by in RESPIRATORY | Comments Off on Cardiopulmonary Rehabilitation
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