Peripheral Arterial Disease Extremity

Transcription

1 Peripheral Arterial Disease Lower Extremity 05 Contributor Dr Steven Chong Advisors Dr Ashish Anil Dr Tay Jam Chin Introduction Risk Factors Clinical Presentation Classification History PHYSICAL examination Assessment Measurement of Ankle-Brachial Index (ABI) Differential Diagnoses Management Indications for Referral to Hospital 50 nhg_guideline_ _1112.indd 50

2 Peripheral arterial disease INTRODUCTION Peripheral Arterial Disease (PAD) is an occlusive disease of arteries such as the aorta, iliac and lower limb (LL) arteries. The major cause is peripheral atherosclerosis, while a less common cause is thromboembolic disease. The objective definition of PAD is a resting Ankle Brachial Index (ABI) < 0.9. RISK FACTORS These are similar to the coronary risk factors: Diabetes mellitus (DM) Hypertension Hyperlipidemia Smoking Hyperhomocysteinemia Age more than 70 years # Known atherosclerotic coronary, carotid or renal arterial disease # May consider age > 50 years as risk factor if other risk factors are present especially DM and smoking Classification PVD (Fontaine s classification): Stage 1 - Asymptomatic Stage 2 - Pain on walking 2A - Mild claudication (Distance more than 200 metres) 2B - Moderate to severe claudication (Distance less than 200 metres) Stage 3 - Ischaemic rest pain Stage 4 - Ulcerat ion or gangrene Stage 3 and 4 represent the most severe manifestations of PVD and are termed as Critical Limb Ischaemia (CLI). Note: Patients with PAD have the same CVD mortality risk as patients who have had AMI / CVA. oft Tissue Strain Clinical Presentation Patients with PAD can present with classic symptoms of leg ischemia. However, many patients are also asymptomatic. Among the symptomatic patients, atypical symptoms are more common than classic claudication. Atypical symptoms can include symptoms similar to classic claudication but not involving the calves or resolving within 10 minutes of rest. 51 nhg_guideline_ _1112.indd 51

3 peripheral arterial disease History Assess for risk factors and past medical history Early Symptoms Late Symptoms / Signs Acute Critical Limb Ischaemia Intermittent Classic Claudication Common site is the calf/calves Other sites can be buttock, hip, thigh or foot Constant claudication distance, relieved within 10 minutes on resting Atypical Symptoms Similar to classic claudication but does not cause patient to stop walking Similar to classic claudication but does not resolve within 10 minutes of rest Leg pain on both exertion and rest Acute Limb Ischaemia Pain, pallor, paraesthesia, pulselessness, paralysis (5 P s) Ischaemic Ulcers Painful punched-out ulcers on toes and pressure areas (dorsum, heel or lateral part of foot) in patients with prior claudication symptoms Ischaemic Pain Worse at rest day and night / LL in elevated position, relieved with LL in dependent position Common sites: toes & forefoot Ischaemic Neuropathy Painful, numb or burning sensation of forefoot or toes Sensory disturbances such as of feet, muscular weakness Gangrene Can be asymptomatic 52 nhg_guideline_ _1112.indd 52

4 Peripheral Arterial Disease Physical Examination Inspect: Feet for colour, temperature, integrity of skin and ulcers Palpate: Peripheral pulses (femoral, popliteal, posterior tibial, dorsalis pedis) & grade Abdomen for aortic pulsation Auscultate for bruit: Aortic, renal and femoral bruits Note: severely stenotic vessel no bruit Assessment Assessment is done by performing a resting Ankle- Bachial Index (ABI). ABI should be considered for the following: A) Symptomatic patients B) Patients with abnormal examination eg. weak pulses or ischaemic-appearing foot MeasureMENT OF Ankle-Brachial Index (ABI) Place BP cuff over upper arm Inflate to above systolic BP Place Doppler probe over brachial artery Detect resumption of blood flow If reading differs for both arms, take the higher reading Similarly obtain reading for both ankles (take the higher value) by placing Doppler probe over posterior tibial & dorsalis pedis arteries The highest of the four measurements in the ankles and feet is divided by the higher of the two brachial measurements to obtain the ABI ABI Grading of Severity of Peripheral Arterial Disease C) Patients who are asymptomatic but has one or more of the following: Age 50 who have the above risk factors History of atherosclerotic coronary, carotid and renal artery disease. Age 70 ABI SEVERITY Normal Mild Moderate Severe 53 nhg_guideline_ _1112.indd 53

5 Peripheral Arterial Disease Differential Diagnoses Other vascular causes of lower limb ischaemia: Arterial embolism Dissection Trauma Thrombosis of aneurysm Buerger s disease (thromboangiitis obliterans) Non-vascular causes of pseudoclaudication (variable claudication distance, pain not relieved on standing alone, usually require sitting, taking weight off limb or changing body position) Spinal stenosis OA hip or knee Lumbar radiculopathy Nocturnal leg cramp Diabetic neuropathic pain Venous claudication Note: PAD may co-exist with other disease conditions with similar presentation 54 nhg_guideline_ _1112.indd 54

6 Peripheral Arterial Disease Management Treatment Goals for Patients Improve functional status (symptoms, quality of life and exercise capacity) Preserve limb decrease need for revascularisation procedure Prevent progression of atherosclerosis & reduce cardiovascular morbidty / mortality Supervised exercise training minutes 3 times/week for 12 weeks Pentoxifylline 400 mg BD-TDS x 3-6 months Naftidrofuryl oxalate (Praxilene) 200 mg TDS Regular surveillance Timely referral for revascularisation procedure where needed Control Risk Factors Smoking cessation Treat CVD risk factors: DM, Hypertension, Hyperlipidemia (targets as for patients who had AMI or CVA) Initiate Antiplatelet Therapy Aspirin 100 mg OM (Clopidogrel if aspirin not tolerated) Indications for Referral to Hospital for Further Investigation & Management Critical limb ischaemia (rest pain, ischaemic ulcers, gangrene) Acute limb ischemia pain, pulselessness, paraesthesia, pallor, paralysis (5 P s) ABI < 0.5 even in absence of symptom Claudication distance < 200 m & pain unresponsive to medical therapy, with limitation of daily activity (even if ABI > 0.5) Other vascular causes of lower limb ischaemia (eg. arterial embolism, dissection, trauma, aneurysm) Some patients assessed to be in possible need of revascularization but where ABI may be falsely normal e.g. in diabetics (due to calcified arteries) References 1. ACC / AHA Guidelines for the management of Patients with Peripheral Arterial Disease, October Uptodate website ( 55 nhg_guideline_ _1112.indd 55