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.