Peripheral Vascular Emergencies

In depth

The one-page summary above is what the PDF prints. These sections go further.

Reading the leg: pulses, ABI and toe pressures

Compare both legs: color, temperature, hair, capillary refill, edema and pulses (Open RN grades pulses 0 absent, 1 decreased, 2 normal, 3 bounding). A pulse that cannot be felt is checked with a handheld Doppler and compared with the last documented exam; a new loss of pulse is reported. Unilateral warmth, redness and swelling suggest DVT and are reported at once.

In PAD, a foot raised above the heart blanches and a foot hanging down turns dusky red (dependent rubor); after elevation, venous filling takes more than 15 seconds. Rest pain is usually burning or aching in the forefoot, worse at night with the legs flat, and eased by dangling the legs over the bed. In acute arterial occlusion, the blockage usually sits at the branch point just below the last pulse that can be felt: a palpable femoral pulse with absent popliteal and pedal pulses points to the common femoral bifurcation, and a palpable popliteal pulse with absent pedal pulses points to the popliteal bifurcation.

Acute limb ischemia in depth

Acute limb ischemia is a sudden loss of limb perfusion lasting up to 2 weeks. Embolism (most often from the heart in atrial fibrillation or after an MI) tends to strike a limb with good collaterals, so it is abrupt and severe; thrombosis of a diseased artery, a bypass graft or a stent is often less dramatic because collaterals have formed. Pain is usually the first symptom and may be out of proportion to what is seen. The 2024 ACC/AHA guideline calls acute limb ischemia a vascular emergency needing rapid diagnosis and management; skeletal muscle tolerates ischemia for only about 4 to 6 hours (Merck says 6 to 8).

• Anticoagulation: IV unfractionated heparin on diagnosis unless contraindicated, whatever the cause or level of the occlusion; a direct thrombin inhibitor if the patient has had HIT. The ESVS 2022 update agrees and notes that aPTT, ACT or anti-Xa can guide dosing.
• Revascularization: catheter-directed thrombolysis, catheter or surgical thrombectomy or embolectomy, or bypass for a salvageable limb. Catheter-directed lysis helps occlusions under 14 days old (ACC/AHA); Merck adds that it works best when motor and sensory function are still intact.
• Category III: the limb is not expected to be saved, so amputation is usual (ACC/AHA notes amputation with revascularization can be appropriate after prolonged ischemia). Classic teaching, not read in a source: reperfusing dead muscle floods the blood with potassium, acid and myoglobin.
• Nursing: keep the limb level and padded (heel off the mattress), no heat, no massage, no tight dressings; record sensation and toe movement each check, because new weakness marks an immediately threatened limb.
• Lysis care: bleeding checks at every puncture site, neuro checks and limb checks as ordered.

Reperfusion after hours of ischemia lets capillaries leak into the fixed fascial compartments. The ACC/AHA guideline notes early fasciotomy is linked to fewer amputations and calls prophylactic fasciotomy reasonable for threatened but salvageable limbs (IIa or IIb). Pain on passive stretch and a tense calf are early; the pulse often stays. The full compartment workup, pressure thresholds and positioning are on the CEN Musculoskeletal and Wound Emergencies page. Watch potassium, CK, urine color and acid-base status after reperfusion.

Bypass grafts, surveillance and atheroembolism

Thrombosis of a bypass graft or stent is one of the causes of acute limb ischemia named by ACC/AHA 2024. After a femoral-popliteal or distal bypass, the nurse checks dorsalis pedis and posterior tibial flow by palpation or Doppler with the rest of the neurovascular exam. A signal that was present and is now gone, with pain, pallor or coolness, is a graft occlusion until proven otherwise and is reported to the surgeon at once; sensory or motor loss means the limb is threatened.

Follow-up (ACC/AHA 2024): after a vein bypass or an endovascular procedure, ABI and arterial duplex are reasonable at 1 to 3 months, 6 months and 12 months. A fall in ABI of more than 0.15 suggests the repair is failing. Low-dose rivaroxaban 2.5 mg twice daily with low-dose aspirin (81 mg) is effective in patients not at increased bleeding risk.

Cholesterol (atheroembolic) emboli follow manipulation of a diseased aorta or large artery during catheterization, angioplasty or vascular surgery, and less often anticoagulant or thrombolytic therapy. Plaque debris lodges in small arteries of the skin, muscle, gut and kidney: livedo reticularis, painful discolored toes while larger pulses remain, eosinophilia, eosinophiluria, transient low complement, microscopic hematuria and kidney function that can keep worsening for 3 to 8 weeks. Treatment is supportive (BP, fluid and electrolyte control, dialysis if needed) with a statin. Merck notes anticoagulation has no proven benefit and most experts think it may worsen atheroembolism, so a new heparin order in this picture is worth questioning.

Access-site complications in depth

Femoral access bleeds outward (groin hematoma) or backward into the retroperitoneum, where a large volume can collect with little to see at the groin; in the Bonn series the retroperitoneal bleeds treated by catheter came from the external iliac artery above the inguinal ligament. In a Bonn series of 2,833 femoral PCIs, major vascular complications occurred in 1.9%: retroperitoneal bleeding, dissection with thrombosis, and pseudoaneurysm. Over half of those patients were women and over half were anticoagulated (the series cannot show these are risk factors). emDocs puts retroperitoneal bleeding under 0.2% of femoral procedures; it presents with back or flank pain and can progress to shock.

• Retroperitoneal bleed: notify at once, large-bore IV access, blood for type and crossmatch, hold or reverse anticoagulation as ordered, CT angiography of the abdomen and pelvis, then covered stent, coiling or surgery for active bleeding.
• Hematoma: direct firm pressure at the puncture, mark the border, check distal pulses; an expanding hematoma or falling hemoglobin is reported.
• Pseudoaneurysm: a contained leak through the arterial wall, felt as a pulsatile, tender mass with a bruit. Diagnosis is by duplex; small ones (under about 3 cm in emDocs) may close on their own, larger or symptomatic ones get ultrasound-guided compression or thrombin injection, and surgery when those fail.
• AV fistula: the needle crossed artery and vein. Classic teaching is a continuous (machinery) bruit and thrill without a pulsatile mass. Report it; duplex confirms, and management ranges from observation and compression to repair.
• Arterial occlusion or dissection: a cool, pale leg with a lost pulse below the site is acute limb ischemia.

Radial access avoids most bleeding but can occlude the radial artery (3.9 to 8.1% in the studies reviewed in PMC11664788). It is usually silent because the ulnar artery feeds the hand. Prevention is patent hemostasis: a band tight enough to stop bleeding yet leaving radial flow, kept about 2 hours with patency checked at least hourly. If occlusion is found within 3 to 4 hours of band removal, about 1 hour of ulnar compression with the same band is described; once ultrasound confirms occlusion, 4 weeks of LMWH is an option and raised patency in the review to as much as 86%. Report hand pain, coolness, color change or weakness at once; forearm compartment syndrome after radial access is rare but real.

Carotid endarterectomy and stenting in depth

Hyperperfusion syndrome: after a tight stenosis is opened, flow can exceed what the brain's autoregulation can handle. Signs are a severe headache on the operated side, eye or facial pain, seizures, focal deficits and confusion, usually with high blood pressure; intracerebral hemorrhage is the feared result. In the review by Zhou et al., pooled incidence was about 1.2% with hemorrhage in about 0.7%; it peaks about 12 hours after stenting and about 6 days after endarterectomy, so it can appear after discharge. Prevention and treatment center on blood pressure: stenting studies mostly target under 140/90 mm Hg and under 120/80 in high-risk patients, with readings every 15 minutes or less for at least 24 hours. After endarterectomy the surgeon sets the target. Labetalol and clonidine are proposed because they lower cerebral blood flow; nicardipine titrates easily but may dilate cerebral vessels. Seizures are treated.

Neck hematoma: in ICSS, 6.1% of endarterectomy patients had a neck hematoma and 3.4% a severe one (reoperation, transfusion or longer stay); anticoagulation, atrial fibrillation and female sex raised the risk. A growing hematoma can compress the airway, so new neck swelling, stridor or trouble swallowing means airway support and an immediate call to the surgeon. Cranial nerve injury occurred in 5.5%: facial (lip droop), hypoglossal (tongue deviation, trouble moving food), vagus (hoarseness) and glossopharyngeal (swallowing). In ICSS the median duration was about 30 days among nerve palsies confirmed to resolve, and a few were lasting; check swallowing before oral intake.

Hemodynamic depression: stretching the carotid sinus raises vagal tone, causing bradycardia, hypotension or both; it is mainly described after stenting. Common definitions are SBP under 90 mm Hg and HR under 60/min; most episodes start within 6 hours and settle in 8 to 10 hours, but some last up to 48 hours. Treatment is IV fluids, atropine for bradycardia and a vasopressor if hypotension persists. Persistent depression was linked to major adverse events and hypoperfusion can cause stroke, so it is treated rather than waited out. Atropine use is debated and is usually reserved for bradycardia.

DVT, phlegmasia and catheter-related thrombosis

Findings are often subtle: aching, tenderness, swelling and warmth. A calf more than 3 cm larger than the other (measured 10 cm below the tibial tuberosity) is a specific sign; Homans sign is neither sensitive nor specific. The Wells score sorts pretest probability (3 or more high); a negative D-dimer rules DVT out when probability is low (cut-off age x 10 ng/mL over age 50), and compression duplex ultrasound is the test otherwise.

• Treatment (ASH 2020): home treatment for uncomplicated DVT; a DOAC over warfarin for most patients; a primary course of 3 to 6 months, longer for unprovoked or recurrent clots.
• Activity: Merck says patients may be as active as they can tolerate; elevate the leg on a soft surface while resting.
• Short NSAID courses for pain are acceptable; avoid long courses with anticoagulants.
• IVC filter: ASH 2020 suggests anticoagulation alone rather than adding a filter; a retrievable filter may be considered when anticoagulation cannot be given.
• Stockings: ASH 2020 suggests against routine use to prevent post-thrombotic syndrome; they can still ease swelling and pain.

Phlegmasia cerulea dolens is massive iliofemoral thrombosis that blocks venous outflow so completely that arterial inflow falls: the whole leg is swollen, purple, extremely painful, and pulses fade. Cancer is a common setting. This is an admission with heparin; ASH 2020 says thrombolysis is reasonable to consider for limb-threatening DVT, with catheter-directed preferred over systemic. The nurse tracks pulses, color and sensation.

Catheter-related upper-extremity DVT: arm or neck swelling, aching, distended veins or blue discoloration on the catheter side, though up to half of PICC clots in critically ill patients cause no symptoms. PICCs carry about 2 to 3 times the thrombosis rate of central venous catheters. Treat with anticoagulation for at least 3 months and for as long as the catheter stays. A catheter that works, sits correctly and is still needed can remain; the review lists contraindication to anticoagulation, progressing thrombosis and infection as reasons to consider removal.

VTE prophylaxis: who and how

Virchow's triad (stasis, vessel injury, hypercoagulability) explains the risk factors. Merck lists higher-risk medical patients as those in critical care or with heart failure, cancer, respiratory failure, immobilization of 3 days or more, hormonal medications, known thrombophilia, prior VTE or age 70 or older. Scores such as Padua (high risk at 4 or more) and IMPROVE (increased risk at 2 or more) formalize this, with the IMPROVE bleeding score for bleeding risk.

• ASH 2018 for acutely and critically ill medical patients: a parenteral anticoagulant over none, LMWH preferred over UFH, and LMWH over a DOAC for inpatient prophylaxis.
• Drug prophylaxis over mechanical; mechanical (pneumatic compression or graduated stockings) when no drug is given; one or the other rather than both.
• Prophylaxis stops at discharge for medical patients; it is not extended routinely.
• Long-distance travel over 4 hours: no stockings, LMWH or aspirin for travelers without risk factors; stockings or LMWH for those at substantially increased risk.
• Doses, timing around procedures and HIT recognition are on the Coagulation page.

Chronic venous disease, ulcers and compression

Failed valves or old DVT (post-thrombotic syndrome) leave the leg veins under high pressure. Findings: swelling, often one-sided, hyperpigmentation, stasis dermatitis, hardened skin (lipodermatosclerosis), varicose veins and ulcers near the medial malleolus that are shallow and moist. Arterial ulcers, by contrast, sit on toes and heels and can expose tendon or bone. A low ABI without edema points to arterial disease.

• Elevation: legs above the level of the right atrium for at least 30 minutes, at least 3 times a day (Merck).
• Compression: elastic wraps until edema and ulcer settle, then stockings, about 20 to 30 mm Hg for milder disease and 30 to 40 mm Hg for moderate to severe disease, most pressure at the ankle; an Unna boot (zinc oxide wrap) changed weekly is another option.
• Wounds: hydrocolloid or similar occlusive dressings for light exudate, absorptive dressings for heavy exudate.
• Walking and calf exercises are encouraged.
• Classic teaching kept: no compression on a leg with significant arterial disease, because it can cut off what inflow is left; check pulses (and an ABI when ordered) first.

Stocking technique (MedlinePlus; TRU health care assistant text): put them on first thing in the morning before getting out of bed, when legs are least swollen; if the patient has been up, have them lie with legs raised for at least 15 minutes first. Turn the stocking inside out to the heel, slide it over the foot with the heel in the heel pocket and pull it up the leg. Knee-length stockings end about 2 fingers below the bend of the knee. Smooth every wrinkle (wrinkles cause pressure injury). Classic teaching, not read in a source: once on, never roll or fold the top down, because it makes a tight band. Remove them completely once a day to wash and inspect the skin, then reapply; wash daily and air dry, keep two pairs, and replace every 3 to 6 months as they lose stretch. Report numbness, tingling, pain, blisters, color or temperature change.

PAD care: walking, drugs, feet

• Walking: structured exercise, including supervised exercise therapy, is a core part of PAD care (ACC/AHA 2024); Merck describes about 30 to 60 minutes of walk-rest-walk at least 3 times a week. Walk until pain comes, rest, continue.
• Smoking: advise quitting at every visit, with medication (varenicline, bupropion or nicotine replacement) and counseling; avoid secondhand smoke.
• Antiplatelet: aspirin 75 to 325 mg or clopidogrel 75 mg daily; low-dose rivaroxaban 2.5 mg twice daily plus aspirin in selected patients.
• High-intensity statin aiming for at least a 50% LDL reduction.
• Cilostazol improves walking distance but is contraindicated in heart failure.
• Feet: inspect daily, wash in lukewarm water and dry well, well-fitting shoes, no barefoot walking, no heating pads or hot soaks, podiatry for nails and calluses.

Chronic limb-threatening ischemia (rest pain, nonhealing wounds or gangrene for over 2 weeks) needs vascular evaluation for revascularization, wound care and infection control. Keep the legs level or slightly dependent, keep feet warm with loose socks, float the heels, and protect skin from pressure; elevation worsens the pain.

Buerger disease and Raynaud

Thromboangiitis obliterans (Buerger disease) is segmental inflammation and clotting of small and medium arteries, often with superficial veins, in the hands and feet of people who use tobacco, mostly men aged 30 to 45. It starts with coldness, numbness or burning in the digits, Raynaud phenomenon, claudication in the arch of the foot, migratory superficial phlebitis, then ulcers and digital gangrene. Complete tobacco abstinence is the treatment; with continued use the disease progresses and amputation is common, while prognosis is excellent after quitting. Avoid cold, vasoconstricting drugs and injury from tight shoes.

Raynaud phenomenon is episodic spasm of digital arteries triggered by cold or emotion: fingers turn white, then blue, then red as blood returns. Primary Raynaud (80 to 90%) occurs alone, usually starts before 40 and is mild and symmetric; secondary Raynaud comes with a disease such as systemic sclerosis or lupus, starts later, is more severe and can cause fingertip ulcers. Teaching: keep the whole body warm, wear gloves outdoors and when handling frozen food, stop smoking, avoid caffeine and vasoconstricting drugs (beta blockers, clonidine, ergots, sympathomimetics). Long-acting dihydropyridine calcium channel blockers such as nifedipine are first-line drugs. Report sores, skin breakdown or digits that stay white or blue.

After aortic repair: what to watch

Rupture, dissection, malperfusion and spinal cord protection are on the Aortic Emergencies and Hypertension page. Three later problems come up in exam questions.

Endografts need lifelong imaging: before discharge, at 6 months, at 1 year, then yearly. In the aortoenteric fistula review, a herald bleed occurred in about 60% of patients, with a median of 4 days to massive hemorrhage, and endoscopy found the fistula only 25 to 40% of the time, so any GI bleed in a patient with an aortic graft is reported at once with large-bore access and blood ready. Fluoroquinolones: the levofloxacin label reports more aortic aneurysm and dissection within 2 months of use, worse in older adults, and reserves these drugs for patients with a known aneurysm or higher risk only when no alternative exists; the nurse questions the order and teaches the patient to report sudden chest, back or abdominal pain.

Exam pearls

• Arterial: dangle; venous: elevate. Compression only for venous disease.
• Sudden cold, pale, pulseless leg: notify, heparin, keep level; never elevate, warm or massage.
• Motor weakness or sensory loss beyond the toes makes the limb immediately threatened.
• After revascularization, a palpable pulse does not rule out compartment syndrome.
• Back pain and falling BP after femoral access: retroperitoneal bleed, even with a quiet groin.
• Pulsatile groin mass: pseudoaneurysm. Continuous bruit and thrill without a mass: AV fistula.
• Headache, seizure and high BP days after endarterectomy: hyperperfusion. Neck swelling: airway first.
• Bradycardia and hypotension right after carotid stenting: carotid sinus reflex; fluids and atropine.
• PICC DVT with a working, needed line: anticoagulate and keep the line.
• Blue toes, livedo and rising creatinine weeks after catheterization: cholesterol emboli; anticoagulation does not help.
• Stockings: on before rising, no wrinkles, never rolled, off daily for skin checks, replace every 3 to 6 months.