Charles Sturt University Week 5 Lecture 1 PAD, Peripheral Artery Disease PDF

Warning This material has been produced and communicated to you by or on behalf of Charles Sturt University in accordance with section 113P of the copyright act (Act). The material in this communication may by subject to copyright under the act. Any further reproduction or c...

Warning This material has been produced and communicated to you by or on behalf of Charles Sturt University in accordance with section 113P of the copyright act (Act). The material in this communication may by subject to copyright under the act. Any further reproduction or communication of this material by you may be the subject of copyright protection under this act. Do not remove this notice Week 5 Lecture 1: Pathophysiology, medications, contraindications and exercise testing and prescription for: ATHEROSCLEROSIS ISCHEMIC HEART DISEASE Angina Peripheral artery disease Valve diseases Revascularisation heart failure 2 Peripheral Artery (Arterial) Disease 3  Introduction Complete or partial blockage of the leg arteries by plaque, which leads to narrowing of arteries in lower extremities Results in stenosis or occlusions which can decrease blood flow Global prevalence= 202 million cases 35-40% have claudication, characterised by pain, champing, or aching in calves, thighs and buttocks 1-2% have critical limb ischemia Majority of clients with PAD are asymptomatic or atypical High prevalence of cardiovascular or cerebrovascular events Prevalence of PAD in clients with diabetes: 29% Other common co-morbidities are heart failure and severe pulmonary disease 4 Risk Factors 1. Smoking 2. Diabetes 3. Hypertension 4. Hypercholesterolemia 5. High levels of homocysteine and fibrinogen 6. Increased blood viscosity 7. Elevated cRP 8. Increased age (< 50) 9. Family history of vascular disease cRP increase levels of free radicals, systemic inflammation and thus endothelial dysfunction 5 Pathophysiology Begins with endothelial damage in arteries in the periphery Process is similar to that outlined in atherosclerosis However, impact now affects the peripheries The abnormal blood flow is predicted on the severity of the stenosis Leg pain symptoms described as cramping, aching, tightening and fatigue Calf claudication: flow-limiting lesions in the femoral and popliteal arteries Buttock pain: flow-limiting lesions in the internal iliac arteries Thigh claudication: flow limiting lesions to the profunda femoral artery 6  Normal = 0.91 to 1.30 - 1.40 Mild to moderate PAD = 0.41 to 0.90 Severe PAD = 0.00 to 0.40 Non-compressible, Calcified vessel is >1.30 NB. Classification descriptors and ‘cut- offs’ can vary Normal pulse wave will be multiphasic Reduced blood flow because of PAD will be dampened and monophasic ABI calculated by dividing the systolic pressure in the ankle artery (the higher of the Posterior Tibial Artery and the Dorsalis Pedis Artery) by the systolic brachial pressure  Critical limb ischemia Presence of Ischemic rest pain Foot ulcers (nonhealing) Gangrene attributable to objectively proven arterial occlusive disease Typically lesions present at multiple levels of tibial vessels and vessels in the foot Issue is the reduction in perfusion, even at rest Poor prognosis for limb loss and cardiovascular morbidity or mortality Mortality rates: 25% in the first year, with 25 % will require amputation 9 Signs and Symptoms Atypical: symptoms that are felt to be consistent with PAD but do not meet the classic definition of claudication. Components of a symptom complex typically Relieved with rest Exertional Located in lower extremity Patients with claudication describe symptoms as Cramping, aching, tightening and fatigue Calf is the most common location 10  Symptom severity scales The Fontaine Stages (Stage: Symptoms) The Rutherford Categories (Grade: Category: Symptoms) I: Asymptomatic IIa: Mild claudication 0: 0: Asymptomatic IIb: Moderate to severe claudication 0: 1: Mild claudication III: Ischemic rest pain I: 2: Moderate claudication IV: Ulceration or gangrene I: 3: Severe claudication II: 4: Ischemic rest pain II: 5: Minor tissue loss III: 6: Major tissue loss 11 Clinical Considerations If PAD is present, the patient should be treated as if cardiovascular disease is also present in terms of risk factor modification, since PAD is a heart disease equivalent Exercise is the first treatment option, and must be supervised Followed by peripheral and surgical options depending on the severity 12 Procedures * Exercise is gold standard treatment for increasing walking distance* 1. percutaneous transluminal angioplasty (PTA): open narrowed or blocked blood vessels that supply blood to your legs 2. Bypass grafting: revascularisation 3. Atherectomy: removing atherosclerosis from blood vessels 14  Exercise Testing Particularly important in determining functional limitations Walking – ADLs Muscular strength and endurance Balance PAD patients with declining functional performance are at increased risk for mobility loss with increasing age Include questionnaires in addition to objective assessments Medical Outcomes Study Short Form 36 (SF-36) https://www.brandeis.edu/roybal/docs/SF-36_website_PDF.pdf Walking Impairment Questionnaire (WIQ) http://geriatricphysiotherapy.yolasite.com/resources/Peripheral_Arterial_ Disease_(PAD)_Walking_Impairment_Questionnaire.pdf 15  Cardiovascular and Functional Testing ABI testing particularly useful For clients with moderate lesions (50-70% stenosis) in the aorto-iliac segment (but also observed in other areas) Atypical symptoms – exercise is required to observe a significant reduction in perfusion pressures associated with onset of symptoms Example Measure ABI at rest = >0.90 and 30 mmHg or 20% from baseline measures and takes more than 3 min to normalise Suggests incidence of lower limb revascularisation (functional limitations) 16 Walking performance. Muscle strength & endurance Walking performance: GXT (superior) or constant load: Claudication onset and peak time 6 MWT is valid and reliable Claudication onset and total distance Strength testing PAD patients have compromised planter flexion strength and knee extension power. Common tests: Calculated 1RM leg press (from 5/10RM) High rep muscle endurance testing Isokinetic strength tests 17  Testing recommendations (ASCM) Dose and timing of medication is noted and repeated for any subsequent test Measure ABI bilaterally after 5-10 mins of supine rest, prior to testing Reproducibility. E.g. Use a standardised treadmill protocol that starts with a slow speed followed by a gradual increase Note the onset as close as possible using a numerical scale as previously outlined Allow the participant to recover in the seated position. A 6MWT can be used to objectively assess ambulatory functional limitations for those not amendable to treadmill testing 18  Aerobic Resistance Mode Walking Free weights, weight machines, elastic bands, stability ball (include major muscle groups) Intensity For patients with claudication, walking to RPE 11 to 14, 30% to 80% of 1RM moderate pain in 3 to 5 min followed by rest and resumption of walking Frequency At least three times per week , progressing to five 2 to 3 d/wk times per week as tolerated Duration 30 to 45 min 8 to 10 exercises, 8 to 15 slow reps, 1 to 4 sets Progression Increase of a few min each session up to 50 min Begin with 1 set of 8 reps at RPE 11 to 12 for each goal; increasing speed to 3.0 mph should also be exercise; gradually increase numbers of repetitions, a goal, as the average PAD patient’s walking sets, resistance, and RPE (13 to 14), as tolerated speed is 1.5 to 2.0 mph (180) Goals Improve: Peak walking time; claudication onset Increase skeletal muscle strength and endurance time; Patient-reported outcomes; VO2peak; Functional performance Considerations For asymptomatic PAD, claudication may not be Avoid Valsalva maneuver or straining. a rate-limiting factor to exercise; thus RPE may Use circuit training for selected patients be used to guide exercise intensity Ex Rx as per ASCM guidelines ACSM Guidelines for Exercise Testing & Prescription 11th ed.