Makindo Medical Notes.com

Related Subjects: Acute Kidney Injury |Acute Rhabdomyolysis |Hyperkalaemia

Look for Acute onset Pain, Pallor, Pulselessness, Perishing cold, Paraesthesia, Paralysis. Acute embolus in a normal limb is a surgical emergency needing assessment for embolectomy and an angiogram is generally not needed. Should go to the Operating room.

About

• The limb is potentially salvageable with early surgical intervention
• Time is short - aim for intervention within 6 hours

Aetiology

• Embolic
  • Femoral artery/Popliteal/Saddle embolism at Bifurcation of aorta.
  • Cardiac Embolism - AF, Mural thrombus with MI, ventricular aneurysm, Endocarditis. Classically sudden.
• Thrombosis: in situ from atherosclerosis. Classically slow and staggering onset. Audible bruit possible.

Clinical: 6 Ps

• Check pulse - AF and check for the level of pulses
• Pallor, Paralysis - weakness is seen
• Pulseless, Paraesthesia, loss of sensation
• Pain out of proportion to physical findings
• Perishing with cold, Cap refill >2s
• Gangrene, Muscle damage
• Tender tense calf - compartment syndrome
• Mottled non blanching leg is usually unsalvageable

Investigations

• FBC, U&E, LFTs, Troponin and Check clotting.
• CK - can identify Rhabdomyolysis or MI
• ECG - AF, New MI may need Troponin
• CXR - Cardiomegaly, pulmonary oedema, infection
• Dopplers of leg vessels looking for venous and arterial signals. A normal triphasic arterial wave is reassuring.
• Group and cross match if for surgery
• Angiography of legs invasive by direct femoral arterial puncture
  • Complications: haematoma, infection, dissection, false and true aneurysm formation, contrast reaction and nephropathy
  • Opportunities: allows opportunity for intervention such as angioplasty and stenting which is best in aorta/iliac disease and less so infrainguinal disease

Stages of Acute Limb Ischaemia

Management

• Resuscitate ABC's + High flow O₂ + IV fluids + IV Heparin if directed by surgeons. Analgesia with Morphine 2.5-5 mg slow IV
• Contact Vascular Surgeons immediately and ensure you know the premorbid status, evidence of sensory loss, muscle weakness and compartment tenderness. Surgeons may request IV Heparin bolus usually 5000 u and then an infusion of 1000u/hr adjusted to APTT.
• Plan may be direct to the OR or further assessment e.g. CTA/MRA/DSA and discussion with patient or family as to ceilings of care.
• Those with a more chronic or acute on chronic presentation may have had time to build up a collateral circulation and a less acute cause but best to treat all as emergency prior to senior review.
• Forced alkaline diuresis if severe Rhabdomyolysis (CK very high, dark urine)

Surgical/Medical Management

• Catheter delivered thrombolysis
• Embolectomy and/or Fasciotomy if compartment syndrome
• Arterial bypass of obstruction by connecting aorta to iliac or iliac to femoral artery or even femoral to femoral arteries.
• Amputation in cases where the limb cannot be saved as a life-saving measure. However, for some non-operative palliation may be more appropriate.

Complications

• Beware hyperkalaemia from tissue necrosis
• Compartment syndrome needing fasciotomy
• Sepsis, Acute renal failure, ARDS, Sepsis