Surg Oral Exam: 9. Pulseless Extremitiy
Terms in this set (31)
Differential diagnosis for pulseless extremity?
- Embolus (Cardiac, Arterial, Paradoxical embolus)
- Thrombosis (vascular grafts, atherosclerosis, thrombosis of aneurysm, entrapment syndrome, hypercoagulable, low flow state)
- Trauma (blunt, penetrating, iatrogenic)
A 60 year-old female with a history of atrial fibrillation and medication non-compliance presents in the ED. "My left foot is painful and cold."
"I would first assess the patient's general appearance and vital signs to determine if there is any need for immediate resuscitation with ABCDEs
Relevant HPI for pulseless extremity?
- Trauma? Activity?
- PMH: Vascular disease (PAD, atherosclerosis, aneurysms), Cardiovascular disease (atrial fibrillation, hypertension, diabetes, heart attacks, strokes), Hypercoagulability (Factor V Leiden or malignancy)
- PSH: Arterial bypass, carotid endarterectomy, AAA repair, percutaneous catheterization procedures (e.g. cardiac catheterization via femoral artery), angioplasty/stenting.
- SH: Smoking, alcohol, IV drug use, physical activity, functional status
- Meds: Anticoagulants (warfarin, Rivaroxaban, Lovenox), anti-platelets (aspirin, clopidogrel), statins, ACE-inhibitors, β-blockers, anti-arrhythmics, OCPs
"I would complete a 14-point review of systems focusing on the cardiovascular, neurologic, and extremity systems."
Relevant physical exam for pulseless extremity?
"I would then move on to perform a complete head to toe physical exam focusing on the cardiac, abdominal, peripheral vascular, and extremity components. I would begin my exam by reassessing the patient's vital signs and again determining the need for resuscitation."
• Cardiac: afib
• Abdominal: bruit and palpate for AAA
• Peripheral Vascular: femoral, popliteal, dorsalis pedis, and posterior tibial; axillary, brachial, radial, and ulnar pulses bilaterally. If non-palpable, use Doppler
• Extremity: Blue toe syndrome, petechiae, Assess the 6 P's of acute limb ischemia.
• If suspecting chronic limb ischemia: look for ulcers between or on tips of toes, hair loss on legs, and dry skin
What are the 6 Ps and how to evaluate?
- Pain - Assess with movement
- Pallor - Pale with delayed capillary refill
- Pulselessness - Contralateral pulse consistent with embolic source; lack of contralateral pulse consistent with acute thrombosis on chronic disease
- Poikilothermia - Skin cool to touch
- Paresthesia - Gross sensory exam; >3-4 hours of ischemia. Sensory before motor loss
- Paralysis - Have patient move extremity; motor function deficit indicative of advanced ischemia
Relevant labs for pulseless extremity?
• CBC (WBC, Hgb)
• BMP (baseline creatinine for IV contrast)
• Coags (PT, PTT; especially if on warfarin to determine if INR is sub-therapeutic)
What is the classification for acute extremity ischemia?
: mild pain, intact Cap refill, no motor or sensory deficit, audible arterial and venous pulse; urgent work-up
: severe pain, delayed cap refill, partial motor/sensory deficit, Inaudible arterial, audible venous doppler; emergency surgery
: variable pain, absent cap refill, complete motor/sensory deficit, inaudible arterial/venous doppler; amputation.
Patient with unilateral lower extremity mild pain, intact Cap refill, no motor or sensory deficit, audible arterial and venous pulse. Dx and Tx?
Viable (stage I) acute ischemia
No risk for immediate tissue loss. Dx. Can perform duplex ultrasound, CTA, MRA, or conventional angiogram to assess disease extent.
Tx. Catheter-directed thrombolysis (distal tibial) vs. embolectomy (proximal femoral).
Patient with unilateral lower extremity mild pain, intact Cap refill, no motor or sensory deficit, audible arterial and venous pulse. Patient is a smoker with known PAD. Dx and Tx?
Acute on Chronic Viable Ischemia
Dx. Angiography - thrombolysis vs. surgical bypass graft
Tx. If patent distal vessels and suitable saphenous vein, perform surgical bypass, otherwise thrombolysis.
Patient with unilateral lower extremity severe pain, delayed cap refill, partial motor/sensory deficit, Inaudible arterial, audible venous doppler. Dx and Tx?
Threatened (stage II) acute ischemia
Limb may be salvageable with emergency surgery. Studies likely to delay intervention.
: intraoperative angiogram following embolectomy
: Embolectomy performed by making an arteriotomy at the bifurcation of the common femoral artery. A Fogarty balloon is passed distally to retrieve the clot; retrograde and antegrade bleeding suggest clot removed.
Patient with unilateral lower extremity variable pain, absent cap refill, complete motor/sensory deficit, inaudible arterial/venous doppler. Dx and Tx?
Nonviable (Stage III) acute ischemia
Dx. Amputation, therefore no urgent imaging necessary. Imaging may be needed to determine if revascularization indicated to support healing of the amputation or allow a more distal amputation.
Tx. Prompt amputation to avoid complications such as infection, rhabdomyolysis and hyperkalemia
Relevant studies for pulseless extremity?
• Color Doppler ultrasound: visualization of anatomy and blood flow
• Conventional angiogram: In patients with indication for operative intervention (severe claudication, rest pain, or tissue loss)
• CT angiography (CTA): evaluate anatomy if poor arterial access sites
• MR angiography (MRA): if at risk for contrast nephropathy or has contrast allergy
• EKG: majority of emboli are from a cardiac source; this will also aid in pre-operative surgical risk assessment
• Transesophageal echocardiogram (TEE): to confirm presence of cardiac thromboembolism
What test if suspecting chronic limb ischemia?
ABI: Obtain exercise/stress ABI in patients with history of claudication but a resting ABI > 0.90
o Normal: 1.0 - 1.4
o Borderline: 0.90 - 0.99
o Mild Disease: 0.60 - 0.89
o Moderate Disease: 0.40 - 0.59
Severe Disease: < 0.39
Sudden onset of 6 P's of acute limb ischemia. Dx and Tx?
Acute limb ischemia
- Dx: clinical, no further work up usually indicated
- Tx: < 6 hours: heparin bolus+infusion, OR angiogram revascularization, transition warfarin.
- > 6 hours, prophylactic fasciotomy with heparin bolus+infusion --> warfarin.
Contraindications to thombolysis?
intracranial surgery, intracranial hemorrhage < 3 months, or active bleeding.
What are complications of revascularization?
Prolonged ischemic time and subsequent revascularization predisposes patients to
reperfusion and compartment syndromes, hyperkalemia and rhabdomyolysis
Hyperkalemia following embolectomy in patient with pulseless lower extremity. Dx and Tx?
- K+ released from ischemic/damaged tissue.
: Calcium gluconate for cardioprotection, glucose/insulin/albuterol (transiently moves K+ into cells), then Kayexalate (permanently binds K+ in GI tract).
Rapid development of muscle pain, tenderness, weakness and swelling of lower extremity following embolectomy in patient with pulseless lower extremity. Dx and Tx?
Myoglobin from damaged muscle crystallizes and precipitates in kidney tubules causing ATN.
- Tx: urine alkalinization (bicarb; ↑ solubility of myoglobin) and IV fluids. In addition, removal of dead muscle releasing the myoglobin will expedite recovery.
Presents with pain during rest and passive stretching, motor and sensory loss due to nerve compression in context of embolectomy in patient with lower extremity surgery. Dx and Tx?
- capillary leakage into the interstitial space enclosed by nondistensible fascia. If compartment P exceeds the capillary perfusion P, nutrient flow ceases and progressive ischemia occurs, even with peripheral pulses.
- Dx. A-line into compartment >30 mmHg
- Tx. Fasciotomy - medial and lateral incisions (anterior, lateral, superficial, deep compartments)
Acute limb symptoms for more than two weeks with history of claudication, rest pain LeRiche syndrome, and lower extremity ulceration. Dx and Tx?
Chronic Limb Ischemia (PAD)
• Medical Tx: stop smoking, exercise, diet, ACE-inhibitor, Statin, Aspirin (cilostazol in moderate but no with CHF)
• Surgical Tx: Indications: claudication, rest pain, or tissue loss
- Endovascular intervention is first line as long as failure does not preclude potential future bypass
- Surgical bypass for long-segment disease - Vein graft better than prosthetic --> failure will require amputation (prevent infection and sepsis)
Indications for surgical intervention with pulseless extremity?
Claudication, rest pain, tissue loss
What is blue toe syndrome?
Small vessel rather than large vessel occlusion due to embolic occlusion of digital arteries with atheoembolic material from proximal arterial sources. Characterized by the sudden appearance of a cool, painful, cyanotic toe(s) or forefoot in the presence of strong pedal pulses and a warm foot
What are the 2 main enzymes used in thrombolysis?
rTPA and urokinase
What are the four fascial compartments of the leg encountered in a below-knee amputation?
Anterior, lateral, deep posterior, and superficial posterior
What is the classic initial presentation of compartment syndrome in the lower extremity?
Numbness in the webbed space between the first and second toes due to compression of the deep peroneal nerve
How is a fasciotomy performed?
Via 2 incisions. Compartment pressures are relieved in the leg by medial and lateral incisions. Through the medial incision, long openings are then made in the fascia of the superficial and deep posterior compartments. Through the lateral incision, the anterior and lateral compartments are opened
How do patients with rest pain in their foot classically sleep at night?
By hanging their foot over the edge of bed to aid gravity in increasing blood flow to the extremity
In PAD, what is the triad of claudication, erectile dysfunction, and absent/diminished femoral pulses?
What is the mechanism of action of cilostazol?
PDE-3 inhibitor that results in vasodilation, and also decreases platelet aggregation
In diabetics, why would one obtain a toe-brachial index (TBI) vs. an ABI?
TBI is a more reliable indicator of limb perfusion in diabetics because the small vessels of the toes are frequently spared from medial calcification (which falsely elevates the ABI). Normal TBI is 0.7-0.8. An absolute toe pressure > 30 mmHg is considered favorable for wound healing
Distal vessel embolus, embolectomy or thrombolysis?
A 2013 Cochrane review found no overall difference in limb salvage or death at one year between embolectomy and thrombolysis