Comprehensive clinical reference for DHA · DOH · SCFHS · QCHP examinations and vascular ward practice
Peripheral Arterial Disease (PAD) is caused by atherosclerosis of the lower limb arteries — progressive plaque accumulation leads to luminal narrowing (stenosis) and eventually occlusion. Reduced blood flow causes tissue ischaemia, particularly on exertion. Risk factors mirror those for coronary artery disease: smoking (strongest modifiable), diabetes, hypertension, dyslipidaemia, age, male sex, CKD, and family history.
Atherosclerotic process: Endothelial injury → lipid deposition → foam cell formation → fibrous cap → plaque calcification → stenosis → critical ischaemia or acute thrombosis on plaque rupture.
GCC relevance: Diabetes prevalence 15–20% in Gulf states (among world's highest). Smoking endemic in younger males. Dyslipidaemia underdiagnosed. Combined = accelerated PAD onset, often presenting in 5th–6th decade.
| Stage | Description | Clinical Features | Management Focus |
|---|---|---|---|
| Stage I | Asymptomatic | ABPI <0.9 but no symptoms; detectable by screening | Risk factor modification; exercise; surveillance |
| Stage IIa | Mild claudication | Claudication-free walking >200 m | Supervised exercise therapy; antiplatelet; statin |
| Stage IIb | Moderate–severe claudication | Claudication at <200 m; significant lifestyle limitation | As above + consider revascularisation assessment |
| Stage III | Rest pain | Ischaemic rest pain; worse at night; relieved hanging leg | Urgent vascular review; revascularisation planning |
| Stage IV | Tissue loss | Ischaemic ulceration or gangrene; limb-threatening | Emergency: CLTI pathway, revascularisation or amputation |
| Grade | Category | Clinical Description |
|---|---|---|
| 0 | 0 | Asymptomatic — no haemodynamic abnormality on stress testing |
| I | 1 | Mild claudication |
| 2 | Moderate claudication | |
| 3 | Severe claudication | |
| II | 4 | Ischaemic rest pain |
| III | 5 | Minor tissue loss — non-healing ulcer, focal gangrene with diffuse pedal ischaemia |
| 6 | Major tissue loss — extending above transmetatarsal level; functional foot not salvageable |
Note: Rutherford categories 4–6 correspond to Critical Limb-Threatening Ischaemia (CLTI) — requires urgent revascularisation or amputation planning.
Intermittent Claudication: Reproducible muscle pain (calf most common; also thigh, buttock) precipitated by walking a fixed distance, relieved within minutes of rest. Does NOT occur at rest. Location of pain = level of disease (calf = femoro-popliteal; buttock/thigh = aorto-iliac).
Rest Pain (Fontaine III): Constant burning/aching pain in foot and toes at rest. Worse at night (↓ cardiac output in recumbency ↓ perfusion pressure). Relieved by hanging foot over bed edge or standing (gravity ↑ perfusion). Indicates critical ischaemia.
| ABPI Value | Interpretation |
|---|---|
| >1.3 | Incompressible vessels — calcified (diabetes, CKD); use TBI |
| 0.9–1.3 | Normal |
| 0.8–0.9 | Borderline — mild PAD; compression therapy with caution |
| 0.5–0.8 | Moderate PAD — claudication range |
| 0.4–0.5 | Severe PAD |
| <0.4 | Critical Ischaemia — rest pain/tissue loss likely |
ABPI = Highest ankle systolic BP ÷ Highest brachial systolic BP
Use the highest of DP/PT pressures for ankle; use highest brachial (L or R). Calculate for each limb separately.
Compression therapy rule: ABPI >0.8 = full compression safe. ABPI 0.5–0.8 = modified compression only (specialist guidance). ABPI <0.5 = compression CONTRAINDICATED.
Patient supine, resting for 10–15 min. Room temperature must be warm to prevent vasospasm.
Apply cuff above ankle (2–3 cm above malleolus). Apply gel over dorsalis pedis (DP) artery.
Inflate cuff above systolic, then slowly deflate. Record pressure at which Doppler signal returns — this is ankle systolic BP for DP.
Repeat for posterior tibial (PT) artery. Use the HIGHER of the two ankle values.
Measure brachial systolic BP both arms. Use the HIGHER value.
ABPI = Highest ankle ÷ Highest brachial. Repeat for other leg.
Post-exercise ABPI: If resting ABPI normal but PAD suspected, perform after standardised treadmill walk. A drop of >20% post-exercise is diagnostic of PAD.
Calcified vessels (ABPI >1.3): Common in diabetes and CKD. Vessels incompressible → falsely high ABPI. Use Toe-Brachial Index (TBI) instead. TBI <0.7 = PAD; <0.15 = critical ischaemia.
| Investigation | Purpose | Findings / Interpretation | Nursing Role |
|---|---|---|---|
| Duplex USS | First-line imaging; non-invasive | Maps stenosis/occlusion; velocity ratios >2 = 50% stenosis | Consent, position, explain — no prep needed |
| CT Angiography (CTA) | Pre-revascularisation planning | Visualises aorta to foot; identifies bypass targets | IV contrast — check eGFR, allergy, metformin hold |
| MR Angiography (MRA) | Alternative to CTA; no radiation | Good soft tissue; less useful for calcified vessels | Screen for metallic implants, claustrophobia |
| Digital Subtraction Angio (DSA) | Gold standard; also therapeutic | Real-time; allows PTA/stenting same session | Catheter lab prep; post-procedure groin care |
| TcPO2 | Wound healing potential | >40 mmHg = healing likely; <20 mmHg = unlikely to heal | Apply electrodes; patient warm and still |
| Toe pressure | Calcified vessel assessment | TBI <0.7 = PAD; absolute toe pressure <30 mmHg = CLI | Digital cuffs; warm digit first |
10g Semmes-Weinstein monofilament: Apply perpendicular to skin, buckle the fibre (1 second). Test 10 sites per foot. Loss of sensation = protective sensation absent.
128Hz tuning fork: Place on bony prominence (1st MTP, medial malleolus). Absent vibration sense = at risk.
Pinprick and temperature: Gross assessment of small fibre function.
| Risk | Features | Review Frequency |
|---|---|---|
| Low | No neuropathy, no PAD | Annual |
| Moderate | Neuropathy OR PAD | Every 3–6 months |
| High | Neuropathy + PAD or deformity | Every 1–3 months |
| Active | Ulcer / gangrene present | MDT — weekly minimum |
Probing to Bone Test: Sterile probe inserted into ulcer base — if bone is reached, specificity for osteomyelitis >85%. MRI is gold standard for osteomyelitis confirmation. Raised WBC, CRP, ESR support diagnosis.
Wagner Ulcer Classification:
Grade 0: Pre/post-ulcerative lesion
Grade 1: Superficial ulcer
Grade 2: Deep to tendon/capsule/bone
Grade 3: Deep with abscess/osteomyelitis
Grade 4: Partial foot gangrene
Grade 5: Whole foot gangrene
Effect of quitting smoking: Doubles claudication-free walking distance. Reduces amputation risk by 50%. Reduces cardiovascular mortality by 30–50%. Improves outcomes from revascularisation procedures.
Cessation support: Brief advice at every contact (5As: Ask, Advise, Assess, Assist, Arrange). Pharmacotherapy: varenicline (most effective), NRT, bupropion. Refer to smoking cessation clinic. Document smoking status at every admission.
| Drug Class | Agent / Dose | Indication | Nursing Points |
|---|---|---|---|
| Antiplatelet | Clopidogrel 75mg OD (preferred) Aspirin 75mg OD (if clopidogrel not tolerated) | All PAD patients — reduces MI/stroke/CV death | Monitor for bleeding; take with food; GI protection if needed |
| Statin | Atorvastatin 80mg OD (high-intensity) | All PAD patients regardless of baseline cholesterol; also stabilises plaque | LDL target <1.4 mmol/L; monitor LFTs, myopathy (CK if muscle pain) |
| ACE Inhibitor / ARB | Ramipril 10mg OD / Perindopril / Losartan | Hypertension in PAD; also cardioprotective | BP target <130/80; monitor K⁺, creatinine; avoid in bilateral RAS |
| Antidiabetic | Individualised; SGLT-2i / GLP-1 preferred in high CVD risk | Diabetes with PAD — HbA1c <53 mmol/mol (<7%) | Monitor BM; SGLT-2i: foot hygiene critical (DKA, amputation risk) |
| Cilostazol | 100mg BD (phosphodiesterase inhibitor) | Claudication symptom relief (2nd line) | Contraindicated in heart failure; headache, palpitations common |
| Anticoagulation | Low-dose rivaroxaban 2.5mg BD + aspirin 100mg | COMPASS trial — high CV risk PAD patients | Increased bleeding risk; assess benefit vs risk |
Most effective treatment for claudication. Improves collateral circulation, muscle metabolism, endothelial function, and cardiorespiratory fitness. Preferred over revascularisation for stable claudication (Fontaine IIa/IIb).
Prescription: Minimum 2 hours per week × 3 months (NICE recommendation). Treadmill or track walking to near-maximal claudication pain, then rest, then repeat. Supervised by physiotherapist.
GCC Challenge: Supervised exercise programmes are limited in Gulf region. Heat, cultural barriers, limited physiotherapy access, and patient motivation are obstacles. Nurses should encourage structured home walking programmes as an alternative with documented targets.
Do NOT debride dry ischaemic gangrene until revascularisation is completed or deemed impossible. Debridement without perfusion = worsening tissue loss.
Non-adherent dressings for ischaemic wounds: Mepitel One, silicone foam. Avoid wet-to-dry dressings (traumatic removal). Keep dry eschar dry and protected.
No compression in PAD (ABPI <0.8). Compression in ischaemic limb → gangrene. Always confirm ABPI before applying any compression bandaging.
Access via common femoral artery (groin) or radial artery. Introducer sheath inserted.
Guidewire crossed through stenosis/occlusion under fluoroscopic guidance with contrast.
Balloon catheter inflated to dilate stenosis. Drug-coated balloons (DCB) reduce restenosis.
Stent deployed if recoil or residual stenosis >30%. Bare metal or drug-eluting stents used.
Completion angiogram confirms patency. Sheath removed; haemostasis achieved (manual pressure/closure device).
Groin observations: Haematoma/bruising (can expand rapidly — firm pressure if bleeding). Mark haematoma borders to monitor expansion.
Pulse monitoring: Hourly neurovascular obs on treated limb for first 4–6 hours. Document: colour, warmth, sensation, movement, capillary refill, Doppler signal.
Post-procedure checks: ABPI recheck at 24h (expect improvement). Adequate hydration for contrast clearance. Hold metformin 48h post-contrast if eGFR borderline. Dual antiplatelet (aspirin + clopidogrel) post-stenting — typically 4–6 weeks.
| Procedure | Indication | Conduit |
|---|---|---|
| Femoral-popliteal bypass | SFA occlusion; claudication/CLTI | GSV (preferred) or PTFE |
| Femoral-distal bypass | Tibial/peroneal vessel disease; CLTI | GSV only (prosthetic poor patency below knee) |
| Aorto-bifemoral bypass | Aorto-iliac occlusion (Leriche) | Dacron prosthetic graft |
| Femoral endarterectomy | Common femoral disease | N/A — patch closure |
Leriche Syndrome (aorto-iliac): Triad of bilateral buttock/thigh claudication + absent femoral pulses + erectile dysfunction (males).
Graft Surveillance: Duplex USS at 6 weeks, 3 months, 6 months, 12 months, then annually. Peak systolic velocity >300 cm/s at anastomosis = significant stenosis → intervention needed before occlusion.
| Level | Indications | Rehabilitation Potential |
|---|---|---|
| Toe/ray amputation | Localised gangrene/osteomyelitis | Excellent — shoe modification |
| Transmetatarsal (TMA) | Forefoot gangrene | Good — custom footwear |
| Below-knee (BK / transtibial) | Foot/ankle ischaemia; viable knee | Good — prosthetic limb likely |
| Above-knee (AK / transfemoral) | BK not viable; knee joint involvement | Harder — higher metabolic demand |
| Hip disarticulation | Thigh/hip involvement | Very limited prosthetic options |
Pre-op: Baseline mobility assessment, MDT rehab planning, psychological support, explanation of phantom limb pain.
Stump care: Firm bandaging (shaping for prosthesis), wound inspection, haematoma prevention.
Phantom limb pain: Reassure — normal phenomenon. Gabapentin, pregabalin, mirror therapy, amitriptyline, TENS.
Prosthetic referral: Once stump healed and shaped (6–8 weeks). Physio for gait training.
| Feature | Arterial (Ischaemic) Ulcer | Venous Ulcer | Neuropathic (Diabetic) Ulcer |
|---|---|---|---|
| Location | Toes, heel, dorsum foot, pressure points | Gaiter area (medial malleolus) | Plantar surface, metatarsal heads |
| Wound edge | Punched-out, well-defined | Irregular, sloping edges | Punched-out, callus rim |
| Wound bed | Pale/necrotic base, minimal granulation | Sloughy, moist, granulating | Variable — can appear well-granulating |
| Pain | Severe, constant; worse at night | Dull ache; relieved by elevation | Painless (reduced sensation) |
| Surrounding skin | Pale, shiny, hairless, cold | Haemosiderin staining, lipodermatosclerosis | Callus, dry, neuropathic changes |
| Pulses | Absent / diminished | Present (unless mixed) | May be present (bounding) |
| ABPI | <0.8 (often <0.5) | Normal (0.9–1.3) | May be >1.3 (calcified) |
| Treatment | Revascularisation; non-adherent dressing; NO compression | Compression therapy (4-layer); elevation | Offloading; debridement; infection management |
T — Tissue: Remove non-viable tissue. Sharp/surgical debridement (if perfusion adequate), autolytic (hydrogel), enzymatic, larval therapy. NEVER debride dry eschar in ischaemic limb without revascularisation.
I — Infection/Inflammation: Treat clinical infection with systemic antibiotics. Swab for C&S. Signs: erythema, warmth, purulence, odour, pain, cellulitis. Biofilm: consider antimicrobial dressings (Ag, iodine, PHMB).
M — Moisture Balance: Maintain moist wound environment without maceration. Absorptive dressings for exudate (foam, alginate). Non-adherent for low exudate ischaemic wounds (Mepitel, Adaptic).
E — Edges/Epithelium: Stimulate epithelial migration. Consider NPWT (negative pressure wound therapy) for complex wounds after revascularisation. Skin grafting for large defects once granulation established.
Offloading (diabetic neuropathic ulcer): Total Contact Cast (TCC) = gold standard for plantar neuropathic ulcers. Reduces plantar pressure by 84%. Alternatives: removable cast walker (CROW), forefoot offloading shoes. Essential — patient will continue walking on neuropathic foot without feeling pain.
Pain — Sudden onset severe limb pain; out of proportion to findings
Pallor — White/mottled limb; loss of normal colour
Pulselessness — Absent distal pulses; absent Doppler signal
Paraesthesia — Pins and needles; numbness — indicates nerve ischaemia (urgent)
Paralysis — Inability to move toes/foot — indicates muscle ischaemia (irreversible damage imminent)
Perishing Cold — Limb cold to touch compared to contralateral side; clear demarcation line
Immediate IV heparin bolus (5000 units) — prevents propagation
Urgent CTA or DSA for location mapping
Embolectomy (Fogarty catheter) for embolic cause
Thrombolysis (alteplase/urokinase) if <14 days; no neuro symptoms
Fasciotomy if compartment syndrome develops post-reperfusion
Reperfusion injury: Restoration of blood flow releases free radicals, potassium, myoglobin from necrotic muscle. Monitor: hyperkalaemia (ECG changes), myoglobinaemia, acute kidney injury (urine output, creatinine). IV fluids to maintain urine output >0.5 mL/kg/h.
Compartment syndrome: Post-reperfusion oedema within fascial compartments. Signs: severe pain on passive stretch, tense swollen calf, paraesthesia, pain out of proportion. Compartment pressure >30 mmHg = fasciotomy. Nursing: never elevate limb (reduces perfusion).
Extremely high PAD burden in GCC: Type 2 diabetes prevalence 15–20% (world's highest). Smoking rates high in males. Dyslipidaemia and obesity epidemic. Combined risk factors accelerate atherosclerosis — PAD often presents a decade earlier than Western populations.
Diabetic foot — leading cause of amputation: In GCC hospitals, diabetic foot complications account for the majority of major lower limb amputations. Late presentation, poor glycaemic control, and neuropathy contribute to high amputation rates.
Barefoot walking on hot sand: Cultural and religious practice (mosques, beaches). In patients with diabetic neuropathy, thermal burns from hot surfaces go undetected → infected wounds → amputation. Patient education on protective footwear is a critical nursing intervention.
Heat and peripheral vascular disease: GCC extreme heat causes peripheral vasodilation. This may mask signs of ischaemia — limbs may feel warm despite critically reduced perfusion. Never exclude PAD on warmth alone. Always perform ABPI in high-risk patients.
Limited supervised exercise rehab: Extreme heat, cultural factors, and lack of structured vascular rehabilitation programmes in GCC limit exercise therapy uptake. Nurses should offer structured home-walking plans with clear targets and diary recording.
Vascular infrastructure: Major vascular surgery units in Saudi Arabia (KFSH&RC Riyadh, KAUH), UAE (Cleveland Clinic Abu Dhabi, SKMC), Qatar (HMC Hamad). Tertiary centres offer full endovascular and open surgical services. District hospitals refer for CTA and revascularisation.
DHA (Dubai Health Authority): Diabetic Foot Care Pathway mandates ABPI screening for all diabetic patients. Defines referral thresholds to vascular surgery. Wound care documented in electronic health record.
DOH (Abu Dhabi — Malaffi): Standards for diabetic foot management aligned with IWGDF guidelines. All DFU patients registered in Malaffi system. MDT foot clinics mandated in licensed hospitals.
QCHP (Qatar): Diabetic foot standards include annual vascular screening, neuropathy assessment, patient education. HAMAD/HMC limb salvage pathway active for CLTI patients across Qatar.
SCFHS (Saudi Commission): Nursing competency framework includes vascular assessment, ABPI measurement, wound care, and patient education for chronic limb ischaemia. Exam candidates should know Fontaine staging, ABPI interpretation, 6Ps of ALI, and antiplatelet choices.
Trap 1: ABPI >1.3 does NOT mean normal vessels — it means calcified, incompressible. Do not reassure patient. Order TBI.
Trap 2: Warm foot does NOT exclude ischaemia in GCC climate. Perform Doppler/ABPI if pulses absent.
Trap 3: Do NOT apply compression to a leg with ABPI <0.8 — this is a patient safety issue.
Trap 4: Painless ulcer does NOT mean it is not serious — neuropathic ulcers feel no pain but can lead to amputation.
Trap 5: Dry gangrene should NOT be debrided until revascularisation status is established.