Chronic pulmonary disease and its associated dysfunction have a slow yet progressive course. The person with pulmonary dysfunction often avoids activities that result in the uncomfortable sensation of dyspnea. A slow but steady decrease in these patients' functional activities follows, resulting in progressive aerobic deconditioning. It is not uncommon for someone with pulmonary disease to have lost many functional abilities before ever seeking medical help. The intended outcome of pulmonary rehabilitation is to interrupt this downward spiraling of physical ability, improve exercise performance, decrease the symptom of dyspnea, and improve quality of life.50,51,52
The Guide for Physical Therapist Practice provides a general framework for physical therapy intervention for patients with impaired ventilation, respiration, and aerobic capacity and endurance associated with ventilatory pump dysfunction (Practice Pattern 6F).53 The development of specific anticipated goals and expected outcomes for the individual patient with pulmonary dysfunction can be based on the general goals presented in Box 12.1.
Box 12.1 Examples of General Goals and Outcomes for Patients with Chronic Pulmonary Dysfunction
Patient/client, family, and caregiver understanding of disease process, expectations, goals, and outcomes is enhanced.
Cardiovascular endurance is increased.
Strength, power, and endurance of peripheral muscles are increased.
Performance of physical tasks, both basic activities of daily living and instrumental activities of daily living, is improved.
Strength, power, and endurance of ventilatory muscles are increased.
Independence in airway clearance is improved.
Overall work of breathing is decreased.
Patient/client decision making ability regarding the use of health care resources is improved.
Patient/client self-management of symptoms and self-management of pulmonary disease are enhanced.
The examination of a patient's pulmonary status has several purposes: (1) to evaluate the appropriateness of the patient's participation in a pulmonary rehabilitation program; (2) to determine the therapeutic interventions most appropriate for the participant's plan of care (POC); (3) to monitor the participant's physiological response to exercise; and (4) to appropriately progress the participant's POC over time.
A patient interview should begin with the chief complaint and the patient's perception of why pulmonary rehabilitation is being sought. Commonly, the chief complaint is often SOB and/or loss of function. A medical history contains pertinent pulmonary symptoms specific to that patient: cough, sputum production, wheezing, and SOB. Occupational, social, medication, and family histories should also be obtained and documented.
HR, BP, oxygen saturation (SaO2), respiratory rate, temperature, and presence of pain (usually associated with SOB) should be examined and documented (see Chapter 2, Examination of Vital Signs). An individual's height should be measured, because there is a direct relationship between height and lung volumes. Weight should be measured on a standard scale and each subsequent measurement should be performed on the same scale.
Observation, Inspection, and Palpation
By observing the neck and shoulders of a patient with pulmonary disease, the use of accessory muscles of ventilation can be observed (see Fig. 12.5). A normal configuration of the thorax reveals a ratio of AP to lateral diameter of 2:1. Destruction of the lung parenchyma results in an increase in the AP diameter and a reduction of this ratio (up to 1:1) (see Fig. 12.4). During inhalation and exhalation, both sides of the thorax should move symmetrically; asymmetries should be noted and documented.
Cyanosis is a bluish discoloration of the skin that can be observed periorally, periorbitally, and in nail beds; it indicates acute tissue hypoxia. An indicator of more chronic tissue hypoxia is digital clubbing of the fingers and toes. In digital clubbing, there is an increase in the angle created by the distal phalanx and the point where the nail exits from the digit. The tip of the distal phalanx becomes bulbous (Fig. 12.11).
Digital clubbing is a sign of chronic tissue hypoxia. (a) Normal. (b) Early clubbing with increased angle present between nail and proximal skin. (c) Advanced clubbing; tip of distal phalanx becomes bulbous.
Auscultation of the Lungs
Auscultation involves listening over the chest wall as air enters and exits the lungs. To perform auscultation of the lungs, a stethoscope is placed firmly on the patient's thorax anteriorly, laterally, and posteriorly (Fig. 12.12). The patient is asked to inspire fully through an open mouth, then to exhale quietly. Inhalation and the beginning of exhalation normally produce a soft rustling sound. The end of exhalation is normally silent. This characteristic of a normal breath sound is termed vesicular. When a louder, more hollow, and echoing sound occupies a larger portion of the ventilatory cycle, the breath sounds are referred to as bronchial. When the breath sounds are very quiet and barely audible, they are termed decreased. These three terms—vesicular, bronchial, and decreased—allow the listener to describe the intensity of the breath sound.54
Auscultation of the lungs. A global assessment of lung sounds requires that the therapist listen through a stethoscope, which is placed anteriorly, posteriorly, and laterally on the upper, middle, and lower thorax.
In addition to the description of the intensity of the breath sound, there may be additional sounds and vibrations heard during auscultation. These are called adventitious breath sounds. These sounds are superimposed on the already-described intensity of the breath sound. According to the American College of Chest Physicians and the American Thoracic Society, there are two types of adventitious sounds: crackles and wheezes.55 Crackles, historically termed rales and rhonchi, sound like the rustling of cellophane and have a multitude of potential causes (tissue fibrosis, secretions in the airways, and so forth) while wheezes have been described as high-pitched, coarse, whistling sounds. A decrease in the size of the lumen of the airway will create a wheezing sound, much as stretching the neck of an inflated balloon narrows the passageway through which air must escape and produces a whistling sound.
Measurement of Dyspnea and Quality of Life
Quantifying dyspnea at the beginning and the end of a rehabilitation program and during periods of exacerbation can be accomplished using the Baseline Dyspnea Index (BDI) (Table 12.6).56,57 Quality-of-life (QOL) measures specific to chronic pulmonary dysfunction such as the Chronic Respiratory Questionnaire or the St. George's Respiratory Questionnaire may be helpful in determining the patient's baseline health-related quality of life. The Chronic Respiratory Questionnaire has a subscore for rating dyspnea and the St. George's Respiratory Questionnaire has a subscore for symptoms. Both of these QOL measure as well as the BDI may be helpful in demonstrating improvement made with physical therapy intervention.58,59
Table 12.6Baseline Dyspnea Index ||Download (.pdf) Table 12.6 Baseline Dyspnea Index
|Functional lmpairment ||Magnitude of Effort |
|____Grade 4: ||No Impairment. Able to carry out usual activities and occupation without shortness of breath. ||____Grade 4: ||Extraordinary. Becomes short of breath only with the greatest imaginable effort. No shortness of breath with ordinary effort. |
|____Grade 3: ||Slight Impairment. Distinct impairment in at least one activity but no activities completely abandoned. Reduction in activity at work or in usual activities that seems slight or not clearly caused by shortness of breath. ||____Grade 3: ||Major. Becomes short of breath with effort distinctly submaximal. Tasks performed without pause unless the task requires extraordinary effort that may be performed with pauses. |
|____Grade 2: ||Moderate Impairment. Patient has changed jobs and/or has abandoned at least one usual activity due to shortness of breath. ||____Grade 2: ||Moderate. Becomes short of breath with moderate effort. Tasks performed with occasional pauses and require more time to complete than the average person. |
|____Grade 1: ||Severe Impairment. Patient unable to work or has given up most or all customary activities due to shortness of breath. ||____Grade 1: ||Light. Becomes short of breath with little effort. Tasks performed with little effort or more difficult tasks with frequent pauses and requiring 50%-100% longer to complete than the average person might require. |
|____Grade 0: ||Very Severe Impairment. Unable to work and has given up most or all customary activities due to shortness of breath. ||____Grade 0: ||No Effort. Becomes short of breath at rest, while sitting, or lying down. |
|____W: ||Amount Uncertain. Patient is impaired owing to shortness of breath, but amount cannot be specified. Details are not sufficient to allow impairment to be categorized. ||____W: ||Amount Uncertain. Patient has limited exertional capacity due to shortness of breath, but amount cannot be specified. Details are not sufficient to allow impairment to be categorized. |
|____X: ||Unknown. Information unavailable regarding impairment. ||____X: ||Unknown. Information unavailable regarding limitation of effort. |
|____Y: ||Impaired for Reasons Other than Shortness of Breath. For example, musculoskeletal problem or chest pain. ||____Y: ||Impaired for Reasons Other than Shortness of Breath. For example, musculoskeletal problem or chest pain. |
|Magnitude of Task |
|____Grade 4: ||Extraordinary. Becomes short of breath only with extraordinary activity, such as carrying very heavy loads on the level, lighter loads uphill, or running. No shortness of breath with ordinary tasks. || || |
|____Grade 3: ||Major. Becomes short of breath only with such major activities as walking up a steep hill, climbing more than three flights of stairs, or carrying a moderate load on the level. || || |
|____Grade 2: ||Moderate. Becomes short of breath with moderate or average tasks, such as walking up a gradual hill, climbing less than three flights of stairs, or carrying a light load on the level. || || |
|____Grade 1: ||Light. Becomes short of breath with light activities, such as walking on the level, washing, standing, or shopping. || || |
|____Grade 0: ||No Task. Becomes short of breath at rest, while sitting, or lying down. || || |
|____W: ||Amount Uncertain. Patient has limited exertional capacity due to shortness of breath, but amount cannot be specified. Details are not sufficient to allow impairment to be categorized. || || |
|____X: ||Unknown. Information unavailable regarding limitation of magnitude of task. || || |
|____Y: ||Impaired for Reasons Other than Shortness of Breath. For example, musculoskeletal problem or chest pain. || || |
Examining a patient's functional abilities at baseline using the 6-Minute Walk Test (6-MWT) or the 10-Meter Shuttle Walk Test (10-MSWT) should be used as an outcome measure to document physical improvements following physical therapy intervention.
Patients with pulmonary disease may show peripheral and ventilatory muscle weakness due to deconditioning, malnutrition, steroid use, and systemic effects of the disease process.10,11,60 Muscle weakness can contribute to exercise limitations and an inability to perform activities of daily living (ADL). Therefore, measurement of muscle strength (e.g., manual muscle tests) and inspiratory pressures (e.g., PImax) should be performed to determine the need for strength training during rehabilitation.
Various laboratory studies may be performed to examine patients with pulmonary disease. These include radiology, pulmonary function tests (PFTs) including flow rates, exercise tolerance tests (ETTs), functional performance measures, arterial blood gas (ABG) analysis, SaO2 measurements, and electrocardiograms (ECGs).
Exercise Testing in Patients with Pulmonary Disease
A determination of functional capacity is part of the examination of a patient with pulmonary disease. An ETT can provide the objective information to (1) document a patient's symptomatology and physical impairment; (2) prescribe safe exercise; (3) document changes in oxygenation during exercise and determine the need for supplemental oxygen; and (4) identify any changes in pulmonary function during exercise performance. If the ETT is repeated following physical therapy intervention, it can provide important outcome data.
A number of testing methods are available to determine the maximal oxygen consumption and functional abilities of patients with pulmonary disease. An ETT protocol, usually utilizing a treadmill or cycle ergometer, gradually increases exercise intensity to stress the patient with pulmonary dysfunction to the point of limitation. Vital signs are monitored throughout the test. The ECG, continuously displayed during exercise, records the exercise HR and electrical activity of the cardiac conduction system. BP measurements recorded at 1- to 3-minute intervals during exercise and during recovery from the test provide information on the hemodynamic status of the patient. ABGs measured during exercise provide the best method for determining arterial oxygenation and the adequacy of alveolar ventilation, though the invasive nature of this test limits its use. Arterial SaO2 monitoring provides less information, but the noninvasive nature of the test makes its use more widespread. Oxygen consumption, VO2, is a helpful measure that can be collected during an ETT, but requires equipment not always found in an exercise testing laboratory. A number of ETT protocols are outlined in Table 12.7.61,62,63,64,65,66 (Refer to the section on exercise testing in Chapter 13, Heart Disease, for more information on exercise protocols.) The symptom-limited ETT requires the patient to continue the exercise protocol until symptoms dictate cessation of exercise. Criteria for stopping a pulmonary exercise test are presented in Box 12.2.
Table 12.7Exercise Testing Protocols Used for the Patient with Pulmonary Disease ||Download (.pdf) Table 12.7 Exercise Testing Protocols Used for the Patient with Pulmonary Disease
|Test ||Author(s) ||Protocol |
|Cycle tests ||Jones62 ||Begin at 100 kpm, increase 100 kpm every minute |
| ||Berman and Sutton63 ||Begin at 100 kpm, increase 100 kpm every minute, or 50 kpm if FEV1, is <1 L/sec |
|Treadmill tests ||Bruce et al64 ||Begin at 1.7 mph, 10% treadmill grade; increase both speed and grade every 3 minutes |
| ||Naughton et al65 ||Begin at 1.2 mph 0% grade; increase speed and 3% grade every 2 minutes |
| ||Balke and Ware66 ||Begin at constant speed of 3.3 mph, increase grade 3.5% every minutes |
|10-Meter Shuttle Test ||Revill et al67 ||Walking between two markers, 10 m apart, at increasing walking velocities, which are synchronized to an auditory signal or metronome |
|Walk Test (6- or 12-minute) ||American Thoracic Society69 ||Ambulate (walk) as far as possible in the allotted time |
Box 12.2 Graded Exercise Test Termination Criteria
Maximal shortness of breath
A fall in PaO2 of greater than 20 mm Hg or a PaO2 less than 55 mm Hg
A rise in PaCO2 of greater than 10 mm Hg or greater than 65 mm Hg
Cardiac ischemia or arrhythmias
Symptoms of fatigue
Increase in diastolic blood pressure readings of 20 mm Hg, systolic hypertension greater than 250 mm Hg, decrease in blood pressure with increasing workloads
Signs of insufficient cardiac output
Reaching a ventilatory maximum
From Brannon, F, et al: Cardiopulmonary Rehabilitation: Basic Theory and Application. FA Davis, Philadelphia, 1998, p 300, with permission.
The 10-MSWT is a functional performance measure that uses a recorded audio signal to dictate incrementally increasing walking speeds on a level 10-meter course. Two destination points are placed 10 meters apart. The person is asked to reach each destination point by the time the increasingly frequent audio signal sounds. The results of the 10-MSWT have a positive correlation with VO2 max (maximal oxygen consumption).67,68
The 6-MWT is also a functional performance measure that asks a patient to walk as far as possible in 6 minutes. The patient is allowed to stop and rest during the administration of the test as total distance walked is the recorded result of the test. The 6-MWT has been shown to be a good predictor of functional abilities.69,70 Both the 10-MSWT and the 6-MWT are easy to administer, and the ready availability of the required equipment makes them useful outcome measurements to demonstrate changes in a patient's abilities following physical therapy intervention.
Exercise test data provide information that can be used to determine disability, predict mortality, assess the ability to perform ADL, quantify health-related quality of life, determine the need for oxygen therapy, demonstrate the effectiveness of medication changes, and prescribe exercise.13,68,69,70,71,72 PFTs performed before and after an exercise test document the effects of exercise on lung function. A reduction of greater than or equal to 10% in FEV1 is an indication that exercise provoked airway hyperresponsiveness.73 Finally, a prescription for exercise that will safely promote improved cardiopulmonary fitness can be developed based on the ETT.
Exercise prescription incorporates four variables that together allow the therapist to develop a patient-specific exercise formula designed to produce an increase in functional capacity. These variables are mode, intensity, duration, and frequency.
Any type of sustained aerobic exercise can be used for pulmonary rehabilitation. Lower extremity (LE) activities, including walking, jogging, and cycling, are often used to improve exercise tolerance because these modes of exercise more easily translate into functional abilities. Upper extremity (UE) aerobic exercise (e.g., arm ergometry, free weights) can also be included. The combination of UE and LE training in a rehabilitation program results in improved functional status compared to either exercise alone.74 Many programs utilize a circuit approach (combining a variety of resistive and aerobic exercises) to train different muscle groups and maintain the participant's interest.
Three parameters can be used to prescribe exercise intensity: oxygen consumption, HR, and rating of perceived exertion (RPE) or rating of perceived dyspnea (RPD). Below is a discussion of each means of prescribing exercise intensity.
Exercise Intensity as a Percent of VO2max
An ETT may report functional capacity in terms of maximal VO2. Exercise intensity can be prescribed using a moderate intensity, 40% to 60% of the maximum VO2 achieved on an ETT, or moderate to vigorous intensity, greater than 60% of the maximum VO2 achieved on an ETT.75 Patients with mild to moderate pulmonary disease may be able to exercise for a period of time at these intensities in order to produce a training effect. However, patients with severe pulmonary disease may not tolerate long periods of activity at high intensities (greater than 60% of their maximum). Lowering the exercise intensity may not be the answer for patients with severe pulmonary disease as using a lower exercise intensity has resulted in a lesser to no training effect.76,77 Rather, exercise will be tolerated and a training effect achieved when short bursts of activity using a high percentage of a participant's peak workload are interspersed with low-intensity exercise or rest periods.75,76,77,78,79,80,81,82,83,84 Current research on interval training versus continuous exercise training is presented in Box 12.3 Evidence Summary. There is a dose relationship between exercise intensity and training outcomes, meaning the higher the exercise intensity, the greater the training.50
Box 12.3 Evidence Summary Exercise Training Intensity: Interval versus Continuous Exercise
|Reference ||Subjects ||Design/Intervention ||Duration ||Results ||Comments |
|Beauchamp et al80 (2010) ||8 randomized clinical trials using 388 patients ||Systematic review || ||No difference was found between interval training and continuous training in their effect on exercise capacity or health-related QOL measures in patients with COPD. || |
|Nasis et al81 (2009) ||42 patients with COPD (FEV1 42% predicted) || |
Randomized clinical trial (RCT) of 2 treatment groups:
Interval training group using 126% of peak workload from cycle ergometer test
Continuous training group using 76% of peak workload from cycle ergometer test
|Both groups: 3 sessions per week for 10 weeks. Interval training group used 30 sec of training with 30 sec of rest for 45 min on cycle ergometer. Continuous session was 30 min on cycle ergometer. ||BODE index scores (by reducing dyspnea scores and increasing the 6-MWT distance) were significantly improved in both groups. There was no significant difference between the groups on these measures. ||If interval training is as good as continuous exercise in lowering the BODE index, which is a prognostic indicator, then both training strategies would be beneficial to patients with COPD. |
|Arnardottir et al82 (2007) ||60 patients with COPD (FEV1 of 32%-35% predicted) || |
RCT of 2 treatment groups:
Interval training group using alternating 80% and 30%-40% of peak workload from cycle ergometer test
Continuous training group using 65% of peak workload from cycle ergometer test
|Both groups: 2 sessions of 39 min of exercise twice weekly for 16 weeks. Interval training group alternated between 3 min of high-intensity training with 3 min of low-intensity training for 39 minutes. Continuous training group performed 39 min of continuous exercise on cycle ergometer. ||Peak work and VO2 peak were significantly increased in each group. Functional capacity, dyspnea ratings, and health-related QOL measures were significantly improved in each group. There was no difference in the improvement between groups. ||If interval training is as effective as continuous exercise, then interval training is beneficial for those patients who cannot sustain long periods of activity. |
|Varga et al83 (2007) ||71 patients with COPD (FEV1 of 55% of predicted) || |
Pre-test, post-test clinical trial of 3 treatment groups.
Interval training group using alternating 90% and 50% of peak workload using cycle ergometer
Continuous training group using 80% of peak workload using cycle ergometer
Self-paced group used the maximum load tolerated using either a cycle ergometer, level walking, or stair climbing
|All groups: 45 min per session, 3 times per week for 8 weeks. Interval training group: 2 min of high-intensity training alternating with 1 min of low-intensity training for 30 min with 7.5 min warm-up and 7.5 min cool-down. Continuous training group: 45 min on cycle ergometer. Self-paced group: exercised starting with 30 min and increasing for 45 min duration by the study's end. ||All three interventions were equally effective in improving the scores on an activity questionnaire. The supervised groups (interval and continuous) groups had a significantly higher peak work rate compared to the self-paced group. Peak VO2 and lactic acidosis thresholds were improved in all groups without statistical significance between groups. ||Participants were assigned to the self-paced group if they lived too far from the research center. Remaining patients were then randomized into the interval training group or the continuous training group. Therefore, this is not a true randomized clinical trial. |
|Puhan et al84 (2006) ||87 patients with COPD, FEV1 of 34% of predicted || |
RCT of 2 treatment groups:
Interval training group using alternating 50% and 10% of peak workload using steep ramped cycle ergometer
Continuous training group using 70% of peak workload using incremental cycle ergometer
|Both groups participated in 12 to 15 sessions of exercise lasting 20 min each over 3 weeks of an in-patient pulmonary rehabilitation program. Interval training: alternating between 20 sec of high-intensity and 40 sec of low-intensity training for 20 minutes. Continuous training: 20 min of continuous cycling. ||Both groups showed a greater than minimally important change in the CRQ scores. Both groups showed statistically significant increases in the 6-MWT (42 m improvement in the interval exercise group after training and 37 m improvement in the continuous exercise group after training). ||Changes in the 6-MWT, although statistically significant, did not approach the clinically significant difference of 54 m. Patients assigned to the interval training group had better adherence than those in the continuous training group. Therefore, it might be worth considering using interval training to improve exercise adherence. |
Exercise Intensity as a Percent of Heart Rate Reserve
While using a percentage of VO2 may be the most accurate method of prescribing exercise from a graded exercise test, it does not give the clinician a means to monitor exercise intensity during actual performance of the exercise. There is a relationship between increasing workloads, increasing VO2, and increasing HR, making exercising HR a practical choice for measuring and monitoring exercise intensity.85 The target heart rate range (THRR) defines a wide, safe, and effective range of exercise intensity that can be performed during the treatment session. The target heart rate (THR) for a specific patient defines a more narrow HR (within the prescribed THRR) that will be most appropriate to ensure aerobic training and patient adherence.
A common method to determine a patient's THRR and the THR is using the heart rate reserve (HRR) method or Karvonen's formula.75 The HRR is the difference between the resting HR (HRrest) in the seated position and the maximal HR (HRmax) achieved on an ETT. To calculate the THRR, percentages (40% and 85%) of the HRR are added to the resting HR. Karvonen's formula for determining the upper and lower limits of the THRR is:
For example, a person achieves a maximal HR of 165 beats per minute (beats/min) on an ETT. The person's resting HR was 85 beats/min. The HRR is calculated to be 165 (85 = 80 beats/min; 40% of 80 beats/min (32) + resting HR (85) = 117 beats/min; 85% of 80 beats/min (68) + resting HR (85) = 153 beats/min. Thus, for this person, a THRR of 117 to 153 beats/min has been calculated from the exercise test data.
Determination of the appropriate THR is based on a complete patient's history as well as data from all tests and measurements. Patients with mild to moderate pulmonary disease may not have a pulmonary limitation to their ability to perform exercise; therefore, a maximal cardiovascular exercise test is likely to have been performed. If the patient has no other concomitant diseases, has no musculoskeletal or neurological constraints, and is committed to exercise, the higher end of the THRR could be used. For example, if the THRR was determined to be 117 to 153, the THR for this person could be at the high end or 141 to 153. If, on the other hand, the patient had other co-morbidities, such as Musculoskeletal, neurological, or renal issues, and has no exercise experience, then the middle (129 to 141) or even lower (117 to 129) end of the THRR might be used.
Patients with severe pulmonary impairment will likely approach their ventilatory maximum before their cardiovascular maximum is reached; that is, their peak exercise HR may be lower than their cardiovascular HR maximum owing to pulmonary constraints. For these patients, exercise intensities that approach their maximum ventilatory symptoms can be used. This may translate into the upper end of the THRR as calculated by Karvonen's formula or even higher.61,79 According to the Guidelines for Pulmonary Rehabilitation from the American College of Chest Physicians (ACCP) and the American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR), an exercise intensity that uses a high percentage of the patient's peak exercise capacity is well tolerated and physiological training effects have been documented.79 However, they caution that lower intensity exercise may be associated with better adherence.79 It should be emphasized that exercise intensity, when prescribed by HR, should have an upper and a lower HR limit, not a single number.
Exercise Intensity by Rating of Perceived Exertion or Rating of Perceived Dyspnea
With severe pulmonary disease, dyspnea is often reported as the limiting factor in the patient's ability to perform exercise. Using HR to prescribe exercise, as described in the previous section, does not always directly address the cause of physical limitation in patients with low ventilatory reserve. Borg's RPE is often used as a means of prescribing exercise intensity for patients with cardiovascular and pulmonary diseases.75,86 Using the RPE scale allows the patient to self-regulate exercise intensity based on his or her perception of exertion (Table 12.8). RPE has been correlated with VO2, making it a useful means of prescribing and monitoring exercise intensity. Perceived exertion ratings of 3, 4, and 5 were correlated with 60%, 72%, and 78% of VO2max, respectively.80 A variation of the RPE scale uses rating of perceived dyspnea (RPD) as a gauge for exercise intensity87,88 (Table 12.9). Perceived dyspnea ratings between 3 (moderate SOB) and 6 (between severe and very severe SOB) define the range within which patients with pulmonary dysfunction generally exercise. A rating of up to 3 corresponds approximately to 50% of VO2max. A rating of about 6 (between 4 and 8) corresponds to approximately 80% of VO2max89 (see also Chapter 13, Heart Disease, for additional information).
Table 12.8Rating of Perceived Exertion: The Borg CR10 Scale ||Download (.pdf) Table 12.8 Rating of Perceived Exertion: The Borg CR10 Scale
|The Borg CR10 Scale® |
|0 ||Nothing at all ||"No P" |
|0.3 || || |
|0.5 ||Extremely weak ||Just noticeable |
|1 ||Very weak || |
|1.5 || || |
|2 ||Weak ||Light |
|2.5 || || |
|3 ||Moderate || |
|4 || || |
|5 ||Strong ||Heavy |
|6 || || |
|7 ||Very strong || |
|8 || || |
|9 || || |
|10 ||Extremely strong ||"Max P" |
|11 || || |
|12 ||Absolute maximum ||Highest possible |
Table 12.9Rating of Perceived Shortness of Breath ||Download (.pdf) Table 12.9 Rating of Perceived Shortness of Breath
|Scale ||Perceived Shortness of Breath |
|0 ||Nothing at all |
|0.5 ||Very, very slight (just noticeable) |
|1 ||Very slight |
|2 ||Slight |
|3 ||Moderate |
|4 ||Somewhat severe |
|5 ||Severe |
|6 || |
|7 ||Very severe |
|8 || |
|9 ||Very, very severe (almost maximal) |
|10 ||Maximal |
Clinicians often prefer to prescribe exercise by utilizing a combination of parameters (e.g., THR and RPE and RPD).
Exercising within prescribed exercise intensity for at least 20 to 30 minutes is recommended.75 The duration of the training session varies according to patient tolerance, with some participants not being able to maintain continuous exercise for 20 to 30 minutes. Frequent rest periods can be interspersed with exercise to accomplish a total of 20 to 30 minutes of discontinuous exercise.
The frequency of exercise refers to the number of sessions performed on a weekly basis during the exercise-training period. The frequency of exercise is often dependent on the intensity that can be achieved and the duration that can be maintained. If 20 to 30 minutes of continuous aerobic exercise can be accomplished within the THR, then three to five evenly spaced workouts per week are recommended. More frequent exercise sessions are recommended for patients with lower functional abilities. One to two daily sessions are advisable for patients with very low functional work capacities.
The aerobic exercise training portion of a pulmonary rehabilitation session includes the following components: check-in, warm-up, aerobic exercise, and cool-down. The check-in period is a time to obtain baseline data, including resting HR, respiratory rate, BP, oxygen saturation, auscultation of the lungs, and weight. It is also the time to discuss medication schedules, any problems the patient may have encountered since last visit, and any changes that need to be addressed by a member of the pulmonary rehabilitation team, such as a change in flow rates, cough, or sputum production. If the patient were found to have a significant decrease in FEV1 on the ETT, a maintenance drug would typically be prescribed to reduce or minimize pulmonary symptoms. PFTs with a handheld device may be performed pre and post exercise to assess the impact of the maintenance medication. The potential need for use of a beta-2 adrenergic inhaler before exercise should be determined. If a patient is found to have a significant decrease in oxygenation with exercise, supplemental oxygen should be readied before initiation of physical activity.
The warm-up component is a time to slowly increase the HR and BP to ready the cardiovascular system for aerobic exercise. For those patients with mild to moderate lung disease who had a cardiovascular end point to their exercise test, the warm-up is usually accomplished by performing the same mode of exercise that will be used in the aerobic portion of the program but at a lower intensity, with an emphasis on controlled breathing. For example, cycling with no resistance could be used as a warm-up activity for a biking program. The warm-up for patients performing continuous exercise lasts between 5 and 10 minutes. For patients with severe lung disease who are prescribed short bursts of high-intensity exercise, there is little opportunity for a warm-up. In these situations, the program should be designed so that each exercise bout of the circuit gradually builds on the previous exercise to ramp up activity.
The aerobic portion of the exercise session consists of a mode or modes of aerobic activity at the appropriate intensity to maintain the THR of the exercise prescription for the advised duration. This portion of the program lasts for at least 20 minutes of either continuous or discontinuous activity. Participant monitoring can be accomplished using RPE and RPD scales, and measures of HR, respiratory rate, and SaO2 (oximetry).
The aerobic training period should be followed immediately by a cool-down period consisting of a slow decline in exercise intensity as the patient nears completion of the circuit. This may consist of 5 to 10 minutes of low-level aerobic activities that slowly return the cardiovascular system to near pre-exercise levels or ramping down of the intensity of short bouts of exercise. Again, there is an emphasis on controlled breathing.
Finally, stretching exercises are performed to maintain joint and muscle integrity and to help prevent injury. Stretching exercises should be performed during exhalation to prevent a Valsalva maneuver, which would worsen a participant's pulmonary capabilities. Patients often use accessory muscles of ventilation during the exercise program; therefore, the muscles of the neck and UEs should be incorporated into the stretching program.
General Strength Training
While cardiopulmonary endurance training through aerobic exercise is the mainstay of pulmonary rehabilitation, generalized strength training has been found to counter the systemic effects of COPD that result in peripheral and ventilatory muscle weakness. Strength of both UEs and LEs has been shown to increase with appropriate training. Strength training can use similar modes of exercise as the endurance training with a change to higher resistance and lower repetitions (i.e., increase the grade of treadmill, increase resistance on stationary cycle or arm ergometer), or weight training of the targeted muscle groups can be prescribed. Participants should be encouraged to refrain from using the Valsalva maneuver during training because this may impair ventilatory exchange and affect exercise performance.
Ventilatory muscle training
Patients with COPD may have weak inspiratory muscles that translate into breathlessness and exercise limitations.79 Ventilatory muscle training devices provide resistance to the inspiratory phase, the expiratory phase, or both phases of ventilation in order to increase the strength and endurance of the muscles of ventilation. Figure 12.13 shows one type of ventilatory muscle training device (Philips Healthcare, Andover, MA). Many research studies have demonstrated the ability to increase ventilatory muscle strength and endurance using these loading devices, especially in the presence of known respiratory muscle weakness.90,91,92,93,94 Ventilatory muscle trainers have also been studied for their ability to alter the perception of dyspnea. A number of researchers have demonstrated a decrease in the severity of dyspnea with ventilatory muscle training during the performance of ADL and during exercise.92,95,97,98 Current research on the benefits of ventilatory muscle training can be found in Box 12.4 Evidence Summary.
Box 12.4 Evidence Summary Ventilatory Muscle Training
|Reference ||Subjects ||Design/Intervention ||Duration ||Results ||Comments |
|Scherer et al91 (2000) ||30 patients with COPD, FEV1 50%-52% predicted, <15% improvement in FEV1 with bronchodilation || |
RCT using two groups:
Treatment: respiratory muscle endurance training using a ventilatory muscle training device
Control: use of incentive spirometry
|Both groups trained twice daily, 15 min per session, 5 days per week for 8 weeks. Treatment group: training apparatus was set at frequency of 60% MVV and tidal volume of 50%-60% VC. ||Significant increase in respiratory muscle endurance post training. Significant increases in PEmax, 6-MWT, VO2 peak and physical components of SF12 after training. No difference between groups in PImax or mental component of the SF12 after training. No difference between groups in dyspnea index or treadmill endurance after training. ||Training apparatus was not a threshold or resistance trainer, but a device that used a fixed tidal volume (TV) and frequency rather than resistance to provide the endurance training. |
|Riera et al92 (2001) ||20 patients with severe COPD FEV1 <50% || |
Randomized control trial using 2 groups:
Treatment: IMT at 60% of SIPmax
Control: zero resistance applied through flowmeter
|Treatment and control groups: 15 min of training on device, 2x/day, 6 days/wk for 6 months. Both groups used flowmeter, with different resistances (see design). || |
Significant increase in SIPmax and PImax after training. Significant increase in SWT distance after training. Significant decrease in dyspnea after training.
Significant improvement in CRQ scores (QOL). No significant change in VO2max′ VEmax′ or Wmax was found in either group after training. No significant change in rate of perceived exertion was found in either group after training.
|Home-based program training was at 60% of sustained inspiratory pressure, that is, approximately 30% of PImax. Device controlled inhalation and exhalation time via visual feedback. |
|Weiner et al93 (2003) ||32 patients with COPD, FEV1 < 50% predicted || |
Randomized control trial using 3 treatment groups + 1 control group:
SIMT group: high-load IMT and low-load EMT
SEMT group: high-load EMT and low-load IMT
SEMT and SIMT group: high-load IMT and EMT
Control group: low-load IMT and EMT
|1 hr/day (30 min of IMT and 30 min of EMT), 6 days/wk for 3 months. High load was ramped up to 60% of max by the end of first month. Low load was 7 cm H2O pressure. ||Groups that trained inspiratory muscles showed a significant increase in PImax. Groups that trained expiratory muscles showed a significant increase in PEmax. Significant increase in 6-MWT in treatment groups. Significant change in dyspnea scores in only the SIMT and SEMT + SIMT group. Significant change in perception of dyspnea in only the SIMT and SEMT + SIMT group. ||Small sample size of only 8 participants per group. Increases in 6-MWT were statistically significant but the SEMT and the SEMT + SIMT did not reach clinical significance for improvement in that test (>54 m). |
|Beckerman et al95 (2005) ||42 patients with COPD, FEV1 < 50% predicted || |
Randomized control trial using 2 groups:
Treatment: began IMT with 15% of PImax load, increasing to 60% by 4 weeks, and increased to maintain 60% of new weekly PImax.
Control: trained with S-IMT at a low load known to not improve inspiratory muscle strength
|Both groups trained for 15 min, 2 times/day, 6 days a week for 12 months. Training for the first month was onsite in the rehabilitation center, the next 11 months was at home with daily phone calls and weekly home visits. Assessments were at 3,6,9, and 12 months. ||6-MWT—significant increase in the treatment group beginning at 3 months with small gains following during next 9 months. No change in the control group. Inspiratory muscle strength: statistically significant increase in PImax in the treatment group (not in the control group) starting at 3 months and continuing throughout the course of study. Dyspnea: treatment group showed a significant decrease in dyspnea beginning at 6 months compared to the control group. HRQOL as measured by SGRQ improved significantly over the control group beginning at 6 months. ||Daily contact for 1 year by a health care professional is unreasonable; therefore the ability to replicate this study is questioned. 11 out of 42 participants did not complete the program (6 were deaths). There was a decrease in hospital length of stays among the treatment group; the number of exacerbations requiring hospitalization was similar between groups. |
|Weiner and Weiner96 (2006) ||28 patients with COPD (FEV1 of 36%-39% predicted) and documented inspiratory muscle weakness || |
Randomized control trial using 2 groups:
Treatment: began IMT with 15% of PImax load, increasing to 60% by 4 weeks, and increased to maintain 60% of new weekly PImax
Control: IMT at a steady load of 7 cm H2O
|Training was 6 days per week, 1 hr/day for 8 weeks for each group. ||Statistically significant increase in the PImax in the training group (46.1 to 58.7 cm H2O), no change in the control group. ||The increase in PImaxwas also correlated to an increase in peak inspiratory flow rates. These higher flow rates would improve the drug deposition to the lungs when using a dry powder inhaler. |
|Magadle et al97 (2007) ||34 patients with COPD (FEV1 45%-46% predicted) currently enrolled in a 12-week pulmonary rehabilitation program of GER || |
Randomized control trial using 2 groups of IMT or S-IMT in addition to continued GER for another 6 months:
Treatment group began IMT training with 15% of PImax load increasing to 60% by 4 weeks, and increased to maintain 60% of new weekly PImax
Control group used S-IMT, the same device as the treatment group but set at a fixed, sufficiently low load that would not provide a training effect
|Pulmonary rehabilitation program was 1.5 hr/day, 3 times per week for the first 12 weeks. Second 6 months included 1 hr/day, 3 days/week of GER for both groups. IMT was performed daily, 6x/wk for the next 8 weeks. It is difficult to distinguish between how the treatment and control groups were handled. ||Following the first 12 weeks of GER, there was significant increase in 6-MWT for all participants. There was no significant improvement in perceived dyspnea or SGRQ scores. After the addition of IMT and S-IMT to GER, there was no further improvement in the 6-MWT in either group. The treatment group showed a significant increase in PImax, and significant improvement in perceived dyspnea and in the SGRQ when compared to the control group. ||The addition of the IMT caused changes in QOL measures and dyspnea ratings that were not found in pulmonary rehabilitation programs of GER alone. As patient's chief complaint is often dyspnea or loss of function, this article is compelling in its recommendation to add IMT to an already existing pulmonary rehabilitation program. |
|Hill et al98 (2006) ||35 subjects with COPD (FEV1 of 37.4% predicted) || |
Randomized control trial using 2 groups:
Treatment (H-IMT) used the maximum load tolerable for 2 min followed by 1 min rest, repeated 7 times
Control: S-IMT used a constant load of 10% of baseline PImax throughout training
|Sessions were 21 min, 3x/wk for 8 weeks for both groups. ||Inspiratory muscle strength significantly increased by 29% in the H-IMT, whereas the S-IMT group increased by 8%. Inspiratory muscle endurance increased by 56% in the H-IMT group whereas the S-IMT group remained unchanged. 6-MWT increased by 27 m in the H-IMT group, with no change in the S-IMT group. QOL measures in the dyspnea and mastery domains increased in both groups. The H-IMT group also showed improvements in the domains of fatigue and emotional functioning. ||Although the results show an increase of 27 m in the 6-MWT, an increase of 54 m is necessary in order to be clinically significant. Therefore, although there is a significant change in the 6-MWT, this will not necessarily relate to clinical improvement. |
A type of ventilatory muscle training device. This is a Threshold® inspiratory muscle trainer for use in improving strength and endurance of the muscles of inspiration. (Photo courtesy of Phillips Respironics, Murrysville, PA.)
Whether training the muscles of ventilation alone translates directly into a clinically significant functional improvement is still not clear. Statistically significant changes in 6-MWT and 10-MSWT data have been demonstrated with ventilatory muscle training.92,93,95,98 However, these changes do not always translate into a clinically significant improvement. For example, a change of greater than 54 meters needs to be realized on a 6-MWT in order to be clinically significant.69 Although Hill et al98 found a statistically significant increase in distance on the 6-MWT in those patients in the ventilatory muscle treatment group, the increase was less than 54 meters, meaning that the increase may not be of clinical value. Following a meta-analysis, Lotters et al90 indicate that the ability to affect functional improvement by the use of ventilatory muscle training is yet to be determined. In patients with severe pulmonary disease and documented ventilatory muscle weakness, training improved their ventilatory muscle strength and endurance and decreased dyspnea.79,94 However, in patients with mild to moderate pulmonary disease, training did not significantly improve ventilatory muscle function. The use of a specific ventilatory muscle training device should be made individually, based on the type of disease, the severity of disease, the presence of inspiratory muscle weakness, and the motivation of the participant.79
A patient's age, functional ability, symptoms, and severity of disease should be considered before any change in the exercise prescription. Exercise progression is appropriate when the individual perceives the exercise session to be easier (lower RPE or target dyspnea) or when the same exercise workload is performed with a lower HR, that is, as the individual physiologically adapts to exercise.
Exercise progression should first be directed toward increasing the number of continuous minutes of exercise and decreasing the amount of time spent in low-intensity exercise or rest periods. When 20 minutes of continuous activity can be accomplished, an increase in exercise duration or intensity can be proposed. Frequency should be adjusted as necessary, based on duration and intensity.
Improved exercise tolerance can occur in multiple settings: an inpatient rehabilitation hospital program, an outpatient pulmonary rehabilitation program, or a home-based program.1 Because of the limited length of stay for many inpatient rehabilitation hospital admissions, most increases in functional capacity occur in an outpatient or home pulmonary rehabilitation program. Generally, conditioning exercises are conducted up to three times per week over a course of 6 to 12 weeks.79 At the end of the rehabilitation program, QOL measurements and dyspnea measurements should be readministered to assess the benefits of pulmonary rehabilitation for each participant. A follow-up 6-MWT or a 10-MSWT should be repeated at the end of the program to assess the change in aerobic conditioning of each participant. Exercise abilities gained in a pulmonary rehabilitation program have been found to gradually decline over 12 to 18 months following completion of the program. Pulmonary rehabilitation programs that last longer than 12 weeks have shown greater sustained benefits than shorter programs.79
An unfortunate reality is that patients with pulmonary dysfunction often have decreased exercise ability following an exacerbation of their disease. It is currently not clear that repeated bouts of pulmonary rehabilitation are beneficial to patients with pulmonary disease.99 Continued support in the form of self-help groups and community exercise groups is essential to maintaining the new level of physical activity obtained with pulmonary rehabilitation.1
A home exercise program (HEP) begins while the participant is enrolled in a pulmonary rehabilitation program. When deemed appropriate (based on exercise response and laboratory data), the participant can be assigned home exercise activities. The patient uses an exercise log to record parameters such as exercise HRs, RPEs, exercise workloads, and any questions that may arise about the HEP (Fig. 12.14). At regular intervals, the therapist analyzes the data and adjusts the HEP as necessary. Progression to an independent HEP is an important rehabilitation goal to promote a participant's lifelong commitment to exercise.
An exercise log that can be used to follow a patient's ability to exercise both during and independent of the pulmonary rehabilitation program.
Although aerobic exercise training is integral to pulmonary rehabilitation, patients require additional services and information to optimize their exercise capability and to improve quality of life. The following sections address other elements of a pulmonary rehabilitation program: patient education, secretion removal techniques, and activity pacing. Smoking cessation should also be considered as a component of pulmonary rehabilitation. (See the section on smoking cessation in the medical management section of this chapter.)
The concept of self-management is promoted in the individual and group educational sessions of a pulmonary rehabilitation program.79 Participants are given individual, one-on-one time to identify their own needs and address issues that are particular to themselves. Benefits from group discussions include support from peers regarding the patient's feelings or needs, learning from others' experiences and questions, and the socialization only a group can provide. Key components of a patient's education program are presented in Box 12.5.
Box 12.5 Education Topics
Anatomy and Physiology of Respiratory Disease
Airway Clearance Techniques
Stress Management and Relaxation
Benefits of Being Smoke Free
Impact of Environmental Factors on COPD
Pharmacology/Use of MDIs
Oxygen Delivery Systems
Psychosocial Aspects of COPD
Management of COPD
Exercise: Effects, Contraindications, Adherence
COPD = chronic obstructive pulmonary disease; MDIs = metered-dose inhalers.
Education makes it possible for patients to assume the responsibility for their own wellness. A patient will carry out the required activities to produce the desired outcome only if the patient knows what to do, knows how to do it, and also wants to do it. This theory of self-efficacy for the patient with pulmonary disease begins with a daily routine that includes self-assessment, adherence to a medication schedule, performance of airway clearance techniques, ADL with pacing, and an appropriate HEP.
Self-assessment is used to recognize the first sign of an exacerbation of the disease: increased dyspnea, decreased exercise tolerance; change in pulmonary flow rates, sputum color or consistency; pedal edema; or any other significant change from baseline. An exacerbation protocol is individually devised that includes a set of standard instructions consistent with the participant's disease and abilities. These instructions may include the use of airway clearance techniques, pacing techniques, or a change in the exercise prescription, as well as contact with the primary care physician for a review of symptoms and pharmacological management.
Managing lung disease can be taught through educational programs that address the needs of individuals with pulmonary disorders. Compared to general education alone, education as part of an individualized comprehensive pulmonary rehabilitation program produced significantly improved exercise abilities, decreased dyspnea, and greater self-efficacy.100 Once the patient has progressed through pulmonary rehabilitation, access to new information and continued support is possible through community support groups (e.g., the Better Breathing Club, sponsored by the American Lung Association).
Secretion Removal Techniques
Secretion retention can interfere with ventilation and the diffusion of oxygen and carbon dioxide in some patients with pulmonary disease. Patients with secretion retention may improve their exercise performance if proper secretion removal techniques have been performed before the physical activity. The preferred practice pattern from the Guide to Physical Therapist Practice for these individuals would be 6C-1: Impaired ventilation, respiration, and aerobic capacity associated with airway clearance dysfunction.53 An individualized program of secretion removal techniques directed to the areas of involvement can optimize ventilation and therefore gas exchange capabilities. Secretion removal techniques include dependent programs that rely on a caregiver (postural drainage, percussion, and shaking) or independent programs, such as the active cycle of breathing technique (ACBT); positive expiratory pressure (PEP), such as the TheraPEP® PEP Therapy System (Smiths Medical, Dublin, OH); airway oscillation devices, such as the Flutter® (Cardinal Health, Dublin, OH) or the Acapella® (Smiths Medical, Dublin, OH); or high-frequency chest compression (HFCC) devices such as The Vest® System (Hill-Rom, St. Paul, MN).
Manual Secretion Removal Techniques
Positioning a patient so that the bronchus of the involved lung segment is perpendicular to the ground is the basis for postural drainage. Using gravity, these positions assist the mucociliary transport system in removing excessive secretions from the tracheobronchial tree. Standard postural drainage positions are presented in Fig. 12.15. Although these postural drainage positions are optimal for gravity drainage of specific lung segments, such positioning may not be realistic for some patients. Modification of these standard positions may prevent any untoward effects yet still enhance secretion removal. Box 12.6 lists precautions that should be considered before instituting postural drainage with patients with signs and symptoms of increased daily pulmonary secretions. These are not absolute contraindications, but relative precautions. The list is not meant to be inclusive; however, it does provide a range of considerations that should be addressed before instituting postural drainage.
Box 12.6 Precautions for Postural Drainage
Precautions for the use of the supine, head lower than feet (Trendelenburg) position:
Circulatory: Congestive heart failure, hypertension
Pulmonary: Pulmonary edema, shortness of breath made worse with lowered head position
Abdominal: Obesity, abdominal distention, hiatal hernia, nausea, recent food consumption, or any patient-specific precautions
Precautions for the use of the side-lying position:
Vascular: Axillofemoral bypass graft
Musculoskeletal: Arthritis, recent rib fracture, shoulder bursitis, tendonitis, or any patient-specific precautions
Positions used for postural drainage. (From Rothstein, J, Roy, S, and Wolf, S: The Rehabilitation Specialist's Handbook, ed 3. FA Davis, Philadelphia, 2005, p 444, with permission.)
Percussion is a force rhythmically applied with the therapist's cupped hands to the patient's chest wall. The percussion technique is applied to a specific area on the thorax that corresponds to an underlying involved lung segment. The technique is typically administered for 3 to 5 minutes over each involved lung segment. Percussion is thought to release the pulmonary secretions from the wall of the airways and into the lumen of the airway. By coupling percussion with the appropriate postural drainage position for a specific lung segment, the probability of secretion removal is enhanced. Because percussion is a force directed to the thorax, there are conditions that would necessitate caution with this technique, such as a fractured rib, a flail chest, osteoporosis, elevated coagulation studies, or a decreased platelet count. These examples are by no means inclusive, but they provide some patient presentations that might require modification (a gentler force applied to the thorax) or elimination of the percussion technique.
Following a deep inhalation, a bouncing maneuver is applied with the therapist's open hands to the rib cage throughout the expiratory phase of breathing. This shaking is applied to a specific area on the thorax that corresponds to the underlying involved lung segment. Five to seven deep breaths with shaking on exhalation are appropriate to hasten the removal of secretions via the mucociliary transport system. Shaking is commonly used following percussion in the appropriate postural drainage position. Because this technique consists of a force applied to the thorax, the same circulatory and musculoskeletal considerations are needed as in the application of percussion.
Once the secretions have been mobilized with postural drainage, percussion, and shaking, the task of removing the secretions from the airways is undertaken using an airway clearance technique. Coughing is the most common and easiest means of clearing the airway. However, it should be noted that high intrathoracic pressures, such as those generated during coughing, could force the closing of small airways in some patients with obstructive pulmonary diseases. By trapping air behind the closed airway, the forced expulsion of air during a cough becomes ineffective in clearing secretions. Huffing is an alternative method of airway clearance that is useful for patients with obstructive pulmonary disease. A huff uses many of the same steps of coughing, without creating the high intrathoracic pressures. The patient is asked to take a deep breath and then rapidly contract the abdominal muscles while forcefully saying "HA HA HA." This allows a forced expiration through a stabilized open airway and makes secretion removal more effective.101
Active Cycle of Breathing Techniques
ACBT is an independent breathing exercise program the patient can perform to clear secretions from the airways that includes (1) a breathing control phase; (2) thoracic expansion exercises; and (3) a forced expiratory technique. ACBT begins with a few minutes of the breathing control phase, defined as relaxed, diaphragmatic, tidal volume breathing. Three to four thoracic expansion exercises, defined as deep inhalations with a 3-second hold followed by a passive exhalation, are performed next. A return to the breathing control phase follows. Depending on the patient's needs, this breathing control phase can last for seconds to minutes. If the patient feels that there are secretions ready to be moved upward, then the forced expiratory technique completes the cycle. If secretions are not ready to be moved, the patient returns to thoracic expansion exercises followed by another period of breathing control for rest and for the patient to assess the status of secretions is their airways. The forced expiratory technique, defined as one or two huffs from tidal volume down to low lung volumes, is used to move secretions higher into the larger airways. The forced expiratory technique is followed by a rest period of breathing control. Using ACBT, secretions are "milked" from smaller to larger airways. Once the secretions have moved into the larger airways, huffs from mid or high lung volumes remove the secretions from the airways. This independent technique has been demonstrated to be as effective as postural drainage, percussion, and shaking.102 Figure 12.16 emphasizes that the patient begins at breathing control and always returns to breathing control for rest and the patient's own assessment of his or her status before moving to either thoracic expansion with breath hold or the forced expiratory technique.
Active cycle of breathing begins with breathing control. All choices are made from the breathing control phase. After each choice is made, thoracic expansion or forced expiratory technique, the patient returns to breathing control to rest and make the next choice.
Oral Airway Oscillation Devices
Airway oscillation devices, such as the Flutter® or the Acapella® (Fig. 12.17), alter the exhaled airflow throughout the airways. The patient inhales a normal size breath. During active exhalation through the device, the exhaled air causes an intermittent backward air pressure that jars the airways. The usual procedure is to exhale 10 or so breaths through the device, followed by two large exhaled volumes through the device and finally a huff or cough to clear mobilized secretions. This routine is repeated until secretions are cleared from the lungs. An airway oscillation device has been shown to help in the removal of secretions from airways.103,104
The Acapella® device used for an independent program of secretion removal. (Courtesy of Smith Medical, Dublin OH, 43017.)
Positive Expiratory Pressure
PEP devices include a valve to regulate expiratory resistance (Fig. 12.18). Inhalation of a normal size breath through the mask or mouthpiece is unresisted. Active exhalation is against a positive expiratory pressure, measuring 10 to 20 cm H2O. A treatment session lasts approximately 10 to 20 minutes with frequent pauses to remove the mask so that the patient can huff to clear secretions. The session is completed when all secretions have been cleared from the airways. PEP has been shown to be as effective as postural drainage, percussion, and shaking.105,106
The PEP system for an independent program of secretion removal. (Courtesy of Smith Medical, Dublin OH, 43017.)
High-Frequency Chest Compression Devices
HFCC devices use an inflatable vest with air channels that is worn over the patient's thorax (Fig. 12.19). The vest is attached to an air compressor that rapidly delivers small air volumes in and out of the vest. The inflation of the vest causes compression to the chest wall and the deflation allows the chest wall to recoil back to its resting position. The patient assumes a comfortable seated position for treatments lasting between 20 and 30 minutes. Secretions may be huffed clear any time throughout the treatment. High-frequency chest wall compression has been shown to be as effective as other secretion removal techniques.107
The high-frequency chest wall compression device (the vest) can be used for an independent program of secretion removal. (Courtesy of Hill-Rom, St. Paul, MN 55126.)
Pursed-lip breathing involves an unresisted inspiration followed by an active oral exhalation through a narrowed (or pursed) mouth opening. When pursed-lip breathing is used by patients with COPD, it may delay or prevent airway collapse, allowing for better gas exchange.108,109 Most patients demonstrate this strategy during periods of dyspnea and rarely need to be taught the technique.
Although diaphragmatic breathing has been taught to patients with chronic pulmonary dysfunction for years, there is little evidence to support its use to improve pulmonary mechanics.109 Some patients require the use of accessory muscles with exercise, with exacerbation of their disease, or with periods of dyspnea. Strengthening accessory muscles of ventilation may be a more effective treatment program than encouraging the use of an ineffective diaphragm with little ability to generate muscle force and/or limited muscle excursion. In patients with very flat diaphragms, focusing on diaphragmatic breathing may even be detrimental.
Activity pacing refers to the performance of any activity within the limits or boundaries of that patient's breathing capacity. For example, an activity that usually causes dyspnea needs to be broken down into component parts such that each component can be performed at a rate that does not exceed breathing abilities. By breaking activities down into component parts and interspersing rest periods between each component, the total activity can be completed without dyspnea or undo fatigue. For example, patients often find that climbing stairs causes a great deal of dyspnea and discomfort. Rather than climbing the entire flight of stairs (usually done too fast and with a breath hold), the patient might be instructed as follows: "Take a deep breath. Now, on exhalation, walk up one (or two or three) stair(s). Now recover. Take in another good breath and walk up the next one (or two or three) stair(s) and recover. Repeat this technique until the flight of stairs is completed." The patient is able to reach the top of the stairs without becoming dyspneic and without undue fatigue. Pacing can and should be part of every activity that would otherwise cause dyspnea. Pacing should be used when performing ADL, ambulation, stair climbing, and other daily tasks. Pacing is not a technique to be used during the aerobic portion of a pulmonary rehabilitation program. During exercise, some shortness of breath is expected to occur.