Continuing Education Activity

Chronic respiratory disorders are a group of respiratory ailments with significant morbidity. Pulmonary rehabilitation is a comprehensive intervention imparted by a multidisciplinary team in chronic respiratory diseases to improve outcomes from a clinical and a healthcare standpoint. This activity will highlight the essential components of the rehabilitation program. It will go over the definition, the physiological basis of the exercise program, indications, structure, conglomerated interventions, and its benefits with evidence highlighting them. This activity highlights the role of the interprofessional team in evaluating and improving care for patients with chronic lung diseases.

Objectives:

• Identify the different components of a pulmonary rehabilitation program.
• Outline the indications for enrollment in pulmonary rehabilitation.
• Review the interventions used in a pulmonary rehabilitation program.
• Summarize the benefits of different modalities of exercises in a pulmonary rehabilitation program.

Introduction

Pulmonary rehabilitation (PR) is a “comprehensive intervention based on a thorough patient assessment followed by patient-tailored therapies that include, but are not limited to exercise training, education, and behavior change, designed to improve the physical and psychological condition of people with chronic respiratory disease and to promote the long-term adherence to health-enhancing behaviors” as per the official American Thoracic Society/ European Respiratory Society statement.[1]

In the National Emphysema Treatment Trial (NETT), it was noted that pulmonary rehabilitation showed benefits in patients with COPD. These patients underwent pulmonary rehabilitation before and after lung volume reduction surgery.[2] No significant improvements in mortality or lung function were presumed as a lack of its efficacy of pulmonary rehabilitation in the past. The use of meaningful endpoints such as exercise tolerance, symptoms of dyspnea, endurance, and quality of life has changed the outlook at pulmonary rehabilitation. When the goals of pulmonary rehabilitation were readdressed, the benefits became clearer.

Anatomy and Physiology

Limitations in work capacity are noted in patients with advanced lung disease due to impaired gas exchange and alveolar ventilation. The resulting decrease in oxygen supply to skeletal muscles can shift towards anaerobic metabolism in the skeletal muscles and build-up of lactic acid.[3] Additionally, there is a decrease in aerobic enzyme activity and a lower fraction of aerobic muscle fibers (Type I).[4] 

A program involving high-intensity exercises can bring about biochemical changes at the cellular level and structural changes in the muscle fibers leading to more aerobic metabolism and a decrease in lactic acid and carbon dioxide production. This leads to delayed onset of fatigue and enhanced exercise tolerance.[3][5]

Indications

Pulmonary rehabilitation benefits patients with chronic lung disease and can be beneficial to patients irrespective of the severity of the lung disease. The majority of earlier literature on pulmonary rehabilitation involves patients with advanced COPD (chronic obstructive pulmonary disease) as it was developed and implemented for them. However, lung function should not be the sole criterion. The selection of patients for pulmonary rehabilitation should be based on symptoms and functional limitations. Patients with mild to moderate COPD also benefit from pulmonary rehabilitation.[6] 

With its benefit in COPD, pulmonary rehabilitation has been extended to other pulmonary disease processes such as asthma, bronchiectasis, interstitial lung diseases, chest wall disorders, and pulmonary hypertension.[7][8][9][10] Additionally, pulmonary rehabilitation can have a significant impact on patients enrolled in lung transplantation. It is employed pre and post-transplant as part of the comprehensive transplant plan.[11] 

According to the recommendations of the American College of Chest Physicians and American Association of Cardiovascular and Pulmonary Rehabilitation (ACCP/AACVPR) practice guidelines, "pulmonary rehabilitation is appropriate for any stable patient with a chronic lung disease who is disabled by respiratory symptoms."[12]

Contraindications

Sometimes, certain underlying medical and physical conditions can prevent patients from effectively participating in the rehabilitation program. Some examples include angina pectoris, decompensated congestive health failure, acute cor-pulmonale, inability to perform exercises due to severe orthopedic impairments, and severe cognitive deficits. Individualized evaluation and plan for patients with potential roadblocks to pulmonary rehabilitation are essential.[3]

Equipment

The pulmonary rehabilitation program can be conducted in the hospital, outpatient, or home. The ability to provide rehabilitation in different settings can help assist patients with varying severity of pulmonary impairments. Equipment for exercise and monitoring are essential components of the program, and they vary depending on the location and setting. Exercise equipment usually includes a treadmill, stationary bicycle, access to stairs or step box, arm crank ergometer, hand weights, resistive exercise bands, and weights. Most researches on the benefits of pulmonary rehabilitation are based on cycle ergometers and treadmills for endurance training and weight machines for resistance training.[13] Essential monitoring devices needed include a pulse oximeter, sphygmomanometer, and tape to measure incremental shuttle walk.

Personnel

Even though no clear guidelines exist regarding the structure of the team itself, several key members are essential to developing a successful pulmonary rehabilitation program. The team usually includes providers, physiotherapists, occupational therapists, respiratory therapists, exercise physiologists, nurses, psychologists, behavior specialists, nutritionists, and social workers. This allows for a multi-modal approach.

The provider in charge serves as the medical director, who is responsible for the intake assessment, development of the plan along with the team, and monitoring of the progress and necessary adjustments to the treatment protocol. The psycho-social morbidity associated with progressive advanced lung disease needs to be understood when making treatment plans. A decrease in anxiety, depression, and improvement in cognition has been demonstrated with comprehensive pulmonary rehabilitation.[13] Thus, input from psychologists and social workers is an essential part of pulmonary rehabilitation as much as exercises and the physical aspect of it.

Preparation

The patient selection process involves evaluating patients' diagnosis and disease severity based on pulmonary function tests. Initial assessment of every patient includes- Borg scale of perceived exertion during supervised baseline incremental exercise test, dyspnea scores during initial maximal exercise capacity, a baseline 6-minute walk test, and Saint George Respiratory Questionnaire (SGRQ) to estimate the quality of life.[13][14][15]

An individualized exercise program is developed based on the assessments mentioned above. Additionally, it is necessary to evaluate the need for supplemental oxygen, rule out cardiovascular limitations, and also assess the safety of exercise interventions. Although a formal cardiopulmonary exercise testing is not necessary for all patients, it helps assess factors contributing to exercise limitations, the safety of exercise, and also prescribing appropriate exercise plan.[14] It may also help in assessing exercise-induced bronchospasm, unmasking cardiac dysrhythmias, and cardiac ischemia.[15][14]

Technique or Treatment

Exercise training focusing on endurance, strength training, and flexibility is the cornerstone of pulmonary rehabilitation. The load during exercise is assessed based on initial assessment and also individual requirements. The load must reflect an individual's daily requirements and escalate as the exercise program progresses incrementally with close monitoring. The goal is to improve patients' aerobic capacity and muscle strength.[1] The crux of endurance training is the conditioning of muscles of ambulation and augmentation of cardiorespiratory fitness, translating to an increase in physical activity with decreased dyspnea and fatigue.[1][16]

Cycling and walking exercises remain the most common form of endurance exercises.[1] Frequency of three to five times per week is recommended for endurance exercise training at an intensity of more than 60% maximal work rate for 20 to 60 minutes.[17] The target training intensity is approximately a Borg dyspnea score of 4 to 6 or a rating of perceived exertion of 12 to 14, which is considered moderate to severe intensity.[18] Interval training is an alternate option to standard endurance training in individuals who have difficulty with continuous training. In interval training, periods of intense training are separated by rest or training at a lower intensity. It also allows achieving most of the benefits of endurance training while reducing dyspnea and fatigue.[19][20][21] 

Resistance training/strength training is another modality of exercise used in pulmonary rehabilitation. It involves training with resistive loads with repetitions, and loads are increased progressively to achieve maximal benefits.[22] Lesser dyspnea is noted in resistance training compared to endurance training and is sometimes better tolerated by patients.[23] Resistance training also helps improve muscle mass and bone mineral density.[24][25][26] The American College of Sports Medicine recommends 1 to 3 sets of 8 to 12 repetitions done on 2 or 3 days each week to improve muscle strength as part of resistance training.[27] About 60 to 70% of one-repetition maximum is considered a suitable initial load.[28] 

The exercise load and repetitions are increased over time in a supervised fashion to help build up strength, muscle mass, and endurance.[27] The best strategy is to include endurance training or interval training along with resistance training in an individual exercise plan as it is known to confer the best benefit than individuals components by themselves.[29] Supplemental oxygen delivery during exercise depends on patients' requirements during rest and during exercise. It has been noted that in COPD patients, supplemental oxygen during exercise in hypoxemic and even in non-hypoxemic patients results in improved exercise tolerance and higher intensity training. It may be due to a decrease in pulmonary artery pressures, carotid body inhibition, and decreased ventilatory drive, and also reduced lactic acid production.[1][30]

Pulmonary rehabilitation is not limited to exercise only. Education, psychosocial support, and nutrition are crucial to achieving patient well-being. Advanced lung diseases have significant psychological and social impacts. It may be more severe if patients need supplemental oxygen.[31] Anxiety and depression are noted among patients with progressive chronic lung diseases.[32]

Alterations in functionality and social life can worsen deconditioning and motivation needed to participate in pulmonary rehabilitation exercises. Hence, it is equally important to focus on the psychological impact of the disease. Pulmonary rehabilitation confers significant benefits in anxiety and depression associated with COPD and also other chronic lung diseases.[13] Breathing techniques are also discussed with the patients to help reduce anxiety and panic. Patients are often screened for untreated depression and anxiety via standardized questionnaires and assessed post-rehabilitation for improvements.[33] If needed, referrals are made to psychologists to help in the management of these co-morbidities.

Nutrition and education are other aspects of pulmonary rehabilitation that are integral to the success of the program. Weight loss and muscle mass loss is a common occurrence in advanced pulmonary diseases. This is multifactorial, often related to increased load on respiratory muscles and also poor oral intake.[34] Detailed dietary history and nutritionist input are helpful in many patients. Patient education involving an understanding of the disease process, treatment options, and rationale, self-management, the role of supplemental oxygen helps participants feel empowered and become active participants in the program.[35]

A written individualized action plan is part of the educational component of the pulmonary rehabilitation program. It involves understanding the symptoms of exacerbations and triggers. It has management strategies for early exacerbations.[36] Many of the patients enrolled in pulmonary rehabilitation have advanced progressive lung disease with other co-morbidities. Advanced care planning is an aspect of comprehensive care that is often overlooked. Advanced care planning involves discussions related to patient care but not restricted to end of life care and advanced directives.[37][38] It can also include discussions about the process of dying and the prevention of suffering.[1]

A maintenance strategy is essential in a pulmonary rehabilitation program. Without a maintenance plan, the benefits appear to diminish by 6-12 months. Quality of life is maintained slightly better than exercise capacity.[39] The maintenance program should include home exercises, a plan for managing the disease process, and a robust psychosocial support network. A structured program with maintenance exercise and self-management plan is essential to have sustained benefits. Ultimately the goal of a pulmonary rehabilitation program is to create a lifestyle change. This requires a dedicated plan followed by continuous reinforcement.

Complications

Complications from pulmonary rehabilitation are mostly due to improper patient selection. Following patient selection, it is essential to create a safe and effective individualized plan. It is vital to screen the participants for co-morbidities, as many of the patients with advanced lung diseases have cardiac and musculoskeletal ailments. Cardiovascular ischemic events and arrhythmias in patients at risk who were not appropriately screened.

Vitals and oxygen levels require monitoring during exercises, and supplemental oxygen should be provided and titrated as needed. The patient's limitations due to muscle wasting and weakness have to be considered to avoid falls and injuries. If available, cardiopulmonary exercise testing before enrollment might help unmask underlying ischemia, cardiac dysrhythmias, musculoskeletal issues.[14] However, most complications can be avoided with appropriate patient selection, careful planning, and close monitoring.

Clinical Significance

 The benefits of the pulmonary rehabilitation program are measured using different parameters. Most of the initial studies in pulmonary rehabilitation were done in patients with COPD, but that has changed recently. Pulmonary rehabilitation is being utilized for patients with different lung diseases, and outcomes may be driven inherently by the underlying disease process.

Survival benefit is one of the important outcomes looked at in pulmonary rehabilitation. In one study, pulmonary rehabilitation initiated within three months of hospital discharge was noted to have a lower risk of mortality at one year; however, other studies have challenged that.[40][41] Quality of life and exercise capacity are important parameters that can be measured. Pulmonary rehabilitation has been shown to improve quality of life as measured on the Chronic Respiratory Disease Questionnaire (CRQ) and St. George's Respiratory Questionnaire (SGRQ).[42][43] 

Multiple studies have shown improvements in maximal exercise capacity and functional exercise capacity with pulmonary rehabilitation in patients with various chronic lung diseases, including post-lung transplant.[44][45][46] Pulmonary rehabilitation was shown to affect the decline of FEV1 over time in COPD patients.[47] Psychosocial benefits from rehabilitation are as important as physical benefits as they are interconnected. Worsening depression and anxiety can adversely affect a person's ability to partake in rehabilitation activities and continuing maintenance programs. Multiple studies have shown clinically relevant improvement in anxiety and depression symptoms.[13]

Chronic respiratory diseases, such as COPD, also have a major monetary impact. Healthcare costs attributable to COPD are estimated to reach approximately $49 billion by 2020 as per the Center for Disease Control (CDC).[48] It includes all aspects of care, including frequent emergency room visits, hospital admissions, exacerbations, and medications. Besides pharmacological interventions, pulmonary rehabilitation is a useful tool that can help reduce exacerbations, readmissions, and hospital length of stay. A written action plan helps reduce health care utilization, costs, and early recovery by early recognition and treatment of exacerbations.[49] The multidisciplinary approach in a pulmonary rehabilitation program can decrease the use of health services and readmissions.[36][50][51]

With smoking contributing to the bulk of the COPD cases and its role in the progression of the disease, pulmonary rehabilitation program provides a unique opportunity to address smoking cessation. Smokers are motivated to stop smoking in a rehabilitation environment with the effects of positive reinforcement.[52] Smoking cessation is often a part of the action plan at the program. The availability of multiple disciplines in pulmonary rehabilitation also provides an opportunity for patients to partake in advanced care planning. Patients enrolled in pulmonary rehabilitation were conducive to having a more detailed advanced care discussion.[53] 

With the increasing volume of evidence in favor of early initiation of pulmonary rehabilitation, the British Thoracic Society guidelines recommend that patients hospitalized for acute exacerbation of COPD should be offered pulmonary rehabilitation at hospital discharge to commence within one month of discharge.[54]

Enhancing Healthcare Team Outcomes

A pulmonary rehabilitation program is a multi-disciplinary team-based intervention. It involves the input of various professionals who work towards a common goal, and studies have shown that working as a team helps improve outcomes.[55] [Level 3] 

The initial assessment and plan take into account the input of a provider from a clinical standpoint. An exercise physiologist working with a physical therapist helps plan the exercise program. Respiratory therapists help with patients’ underlying lung disease and breathing techniques to provide symptom relief.

Psychiatrists and psychologists' assessment before, during, and after is important as depression, anxiety and mental health issues associated with chronic diseases need to be addressed concurrently. Social workers help with addressing issues at home and social hindrances in achieving the ultimate goal of delivering high-quality care. No intervention is successful without a proper follow-up, appropriate medication reconciliation, and education which is imparted by a nursing team.

Many of the professionals in the team are not locked in their roles. Working in a team, they can identify and often fill in the roles of other team members. In a system with so many moving parts, communication is the key. Roadblocks in each step or intervention have to be discussed with other members of the team as it helps in problem-solving and customizing it to patients' needs. Periodic meetings are beneficial to discuss the progress and modifications needed.