<LEAP> highlights the findings and application of Cochrane reviews and other evidence pertinent to the practice of physical therapy. The Cochrane Library is a respected source of reliable evidence related to health care. Cochrane systematic reviews explore the evidence for and against the effectiveness and appropriateness of interventions—medications, surgery, education, nutrition, exercise—and the evidence for and against the use of diagnostic tests for specific conditions. Cochrane reviews are designed to facilitate the decisions of clinicians, patients, and others in health care by providing a careful review and interpretation of research studies published in the scientific literature.1 Each article in this PTJ series summarizes a Cochrane review or other scientific evidence on a single topic and presents clinical scenarios based on real patients or programs to illustrate how the results of the review can be used to directly inform clinical decisions. This article focuses on an older patient with intermittent claudication. Could a supervised exercise program increase the distance he is able to walk before stopping because of pain?
The Inter-Society Consensus for the Management of Peripheral Arterial Disease defines intermittent claudication (IC) as a symptom of peripheral arterial disease in which muscle pain in the lower extremities is produced by exercise and relieved by rest.2 In men and women over the age of 60 years, the prevalence of IC in the United States is 5% and 2.5%, respectively.3
Claudication pain develops as a result of atherosclerosis, a process in which plaque builds up on the inner lining of an artery, narrowing the lumen and reducing blood flow. During exercise, this decrease in blood flow leads to oxygen deprivation to the working muscles, resulting in leg pain. In severe cases, the blood flow is inadequate at rest, resulting in resting leg pain.4 People with IC may have significant functional disability. They are more likely to have advanced systemic atherosclerosis and are at significantly higher risk of fatal cardiac events.3,4
Interventions for IC may include:
medical management of diabetes, hypertension, and hyperlipidemia; and
surgical interventions such as angioplasty and bypass surgery.
There is a large body of literature supporting exercise therapy for patients with IC, and guidelines for exercise prescription are available. The TASC II (Trans-Atlantic Inter-Society Consensus Document on Management of Peripheral Arterial Disease) guidelines2 recommend a walking exercise program with some level of supervision. The speed and grade of walking should induce claudication pain within 3 to 5 minutes. Walking should be stopped when claudication pain is rated as moderate (score of 2 on the Claudication Pain Rating Scale; see Figure), and the patient should rest until the claudication pain has resolved. At that point, the patient should resume walking until moderate claudication pain is induced again. The walking exercise program should begin with exercise and rest cycles of at least 30 minutes and should progress to 60 minutes. The frequency of the walking exercise program should be 3 times a week for 3 or more months. If the patient is able to walk 10 minutes without inducing moderate claudication pain, the intensity can be increased in either speed or grade.
The American Heart Association and American College of Cardiology (AHA/ACC) Guidelines for the Management of Patients With Lower Extremity Peripheral Arterial Disease6 recommend the following key elements of an exercise program for patients with IC:
Supervised treadmill or track walking at an intensity that elicits claudication symptoms within 3 to 5 minutes (a score of 1 on the Claudication Pain Rating Scale)
Walking until the claudication pain is rated as moderate (a score of 2 on the Claudication Pain Rating Scale), followed by standing or sitting rest to permit symptoms to resolve
Repeating these exercise and rest cycles for 35 minutes of intermittent walking
Increasing the exercise program by 5 minutes per session to 50 minutes, 3 to 5 times per week, for a minimum of 12 weeks.
According to a 2000 Cochrane review, individuals with IC who participated in an exercise program had significantly greater pain-free and maximal walking times and distances compared with individuals who were given a placebo or usual care (variations included placebo tablets, laboratory visits for ankle brachial index measurements, advice to maintain usual activity, no exercise, or lifestyle advice).7 An updated literature search was performed in 2008 by Watson et al,8 and the findings of the original Cochrane review were confirmed.
Because the exercise programs in the studies analyzed in the 2008 Cochrane review varied widely, Bendermacher et al9 conducted a Cochrane review in 2009 to evaluate the effects of supervised versus nonsupervised exercise therapy on the maximal walking distance of people with IC. Secondary outcome measures included pain-free treadmill walking distance, mortality, compliance, functional status, and quality of life. Details of the review are shown in the Table.
Supervised exercise programs are more effective than nonsupervised programs in improving treadmill walking distances in patients with IC.9 The evidence suggests that programs focus on walking at an intensity that elicits symptoms (score of 1 on the Claudication Pain Rating Scale) within 3 to 5 minutes, stopping if symptoms become moderate (score of 2 on the Claudication Pain Rating Scale), resting until symptoms have resolved, then resuming walking. The exercise program should be for 30 to 60 minutes of exercise and rest cycles per session, 3 to 5 times per week, for a minimum of 3 months.2,6
<LEAP> Case #6 Exercise for Intermittent Claudication
Can a supervised exercise program help this patient?
Mr. Phillips was a 61-year-old man who was admitted to an acute care hospital after developing a cold right foot. Computed tomographic angiography showed an occlusion of a previous left to right obturator graft, and Mr. Phillips received thrombectomy of the right obturator bypass graft and endarterectomy of the right popliteal artery. His past medical history included coronary artery disease (CAD), myocardial infarction (MI), peripheral arterial disease, hypertension, and hypercholesterolemia. He was independent in all activities of daily living at baseline. He traveled to work by bus and did not drive.
Prior to seeing Mr. Phillips, the therapist considered several factors for exercise testing based on a review of his chart, including a past medical history of CAD and MI, current risk factors for further cardiac events (hypertension and hypercholesterolemia), medications that included beta blockers, and level of function at baseline and during admission. The physical therapist clarified that Mr. Phillips had not experienced angina since his MI. Using established submaximal exercise guidelines,9,15,16 the physical therapist determined that she would stop activity if Mr. Phillips' heart rate exceeded 85% of his maximum heart rate or if his rate of perceived exertion (RPE) exceeded 14.15 The therapist would follow any postoperative recommended blood pressure parameters for this patient, given his vascular intervention, and ensure that the patient's blood pressure response to the given workload was appropriate. Because Mr. Phillips was receiving an uninterrupted dosage of beta-blockers, the therapist chose to calculate the maximum heart rate using the formula: 164–0.7(age).16 The therapist also would monitor for signs and symptoms that would indicate exercise intolerance.
Upon testing, Mr. Phillips complained of pain in his left calf greater than his right and stopped walking after 15 m (50 ft). He also complained of right popliteal incision pain, but this was not a limiting factor for the walking test. Mr. Phillips' goal was to walk 152 m (500 ft) without having to stop. Hemodynamic response, including heart rate, blood pressure, and RPE, was monitored during position changes and throughout activity. Values did not exceed termination guidelines.
How did the physical therapist apply the results of the Cochrane Review to Mr. Phillips?
The physical therapist questioned whether Mr. Phillips would be a good candidate for a supervised exercise program. Using the PICO (Patient, Intervention, Comparison, Outcome) format,17 she asked the question: In a 61-year-old man following lower-limb thrombectomy and endarterectomy, will a supervised exercise regimen be beneficial for increasing walking distance? She determined that the systematic review by Bendermacher et al9 provided relevant information that allowed her to answer her question. The systematic review reported on studies in which the participants included men who were 61 years of age. Although 5 of the 8 studies included in the systematic review had required participants to have stable IC without recent surgery, the physical therapist concluded that this did not prevent application of the results to Mr. Phillips' case. His recent surgery did not limit or preclude exercise. The studies included in the review examined the effects of a supervised walking program, most often treadmill walking, compared with an unsupervised walking program. The primary outcome of the review was maximum walking distance, which also was Mr. Phillips' goal, supporting the use of this particular review in this case.
Based on her assessment of the evidence from the systematic review, the physical therapist recommended a supervised walking program to Mr. Phillips. He agreed to the recommendation and was motivated to exercise to attain his community-level ambulation goals. During the examination on postoperative day 2, Mr. Phillips was educated on the use of the Claudication Pain Rating Scale and was able to walk 24 m (80 ft) self-paced in 68 seconds before experiencing claudication pain, and a further 6 m (20 ft) in 12 seconds before experiencing moderate claudication pain, at which point he stopped walking. Hemodynamic response again was monitored, and termination values were not exceeded.
The hemodynamic response was not the limiting factor to walking during this session; therefore, intensity, time, and type of exercise prescription were based on the literature supporting exercise in IC. In further sessions, the therapist had Mr. Phillips slow his pace in an attempt to maintain pain-free walking for 3 to 5 minutes before the onset of claudication pain. He would walk until he achieved a score of 2 on the Claudication Pain Rating Scale, stop, rest until the pain had resolved, and then resume walking. Exercise and rest cycles would be repeated as tolerated, with a long-term goal of 30 minutes. According to the literature for IC, the frequency of exercise sessions is 3 times per week (TASC II)2 and 3 to 5 times per week (AHA/ACC).6 The literature supporting exercise in patients with CAD recommends exercise at least 3 times per week.15 Based on the literature for patients with IC and for patients with a history of CAD, the physical therapist recommended that Mr. Phillips walk 5 times per week.
How well do the outcomes of the intervention provided to Mr. Phillips match those suggested by the systematic review?
Nine days after surgery, Mr. Phillips ambulated 41 m (135 ft) slowly before reaching moderate claudication pain. He was able to approximate this distance 5 times, with each exercise and rest cycle lasting about 4 minutes. He was seen for 3 physical therapy sessions during his admission. Mr. Phillips reached 27% of his walking distance goal at discharge from inpatient physical therapy. He was motivated to follow up with his local outpatient physical therapy clinic to continue with a supervised exercise program. He adhered to this program, and, at the end of 3 months, Mr. Phillips had reached his goal of walking 152 m (500 ft) without stopping. He continues to progress his walking program with a goal of intermittent walking for 45 minutes most days of the week.
Can you apply the results of the systematic review to your own patients?
The findings of the Cochrane review by Bendermacher et al9 indicate that adult patients with IC benefit from supervised exercise programs in terms of walking distance. Although patients with IC often have comorbidities that may limit exercise tolerance, these comorbidities often do not preclude participation in a safe and effective exercise program. In that case, not only would many patients be appropriate candidates for an exercise program, but they would significantly benefit from one. The findings of the Cochrane review still apply; however, appropriate timing of initiation of the exercise program and application of exercise literature pertaining to each patient's comorbidities should be considered.
What can be advised based on the results of these systematic reviews?
Patients with IC who can safely exercise would benefit from a supervised walking program that includes walking at an intensity that elicits symptoms within 3 to 5 minutes, stopping if symptoms become moderate, resting until symptoms have resolved, and then resuming walking, for 30 to 60 minutes of exercise and rest cycles, 3 to 5 times per week, for a minimum of 3 months.2,6 The physical therapist should prescribe an exercise program individualized to the patient and consider the patient's goals, comorbidities, and response to exercise. After completion of a supervised walking program, strategies to enhance long-term participation in a home walking program should be incorporated.
- © 2011 American Physical Therapy Association