Acute Limb ischemia (ALI)
Definition:
Acute onset (<2 weeks) ischemia is severe hypoperfusion of limb with signs and symptoms including
pain,
... [Show More] paralysis, paresthesia, pulselessness, cold, and pallor which threatens tissue viability. Usually due
to acute arterial occlusion and rarely due to venous etiology.
Criteria for diagnosis
! Must Be Recognized Rapidly. Skeletal Muscle Tolerates Ischemia 4-6 hours!
Onset < 2 weeks
Category I*; Viable: limb not immediately threatened; No muscle weakness; No sensory loss;
Audible arterial and venous doppler
Category II a*; Marginally threatened and salvageable if treated promptly: Mild to moderate
motor or sensory loss; Inaudible arterial and audible venous doppler
Category II b*; Immediately threatened and possibly salvageable if treated immediately; Mild to
moderate motor or sensory loss; Inaudible arterial and audible venous doppler
Category III*; Irreversible: Permanent nerve damage or major tissue loss; Profound sensory loss;
Profound muscle weakness or paralysis; Inaudible arterial and venous doppler
*Categories based on AHA/ACC guideline definition
Ankle Brachial Index <0.5 indicates severe arterial disease
CT and MR angiography can reliably diagnose the location and severity of arterial stenosis or
occlusion (not good for
Arteriography can usually distinguish between thrombosis and embolism
Diagnostic imaging for immediately threatened extremity should be arranged in surgical suite
Clinical presentation (Subjective Information)
Depends on etiology and whether patient has underlying peripheral artery disease
In patients without history of vascular disease symptom onset is more rapid due to lack of
functioning collateral blood vessels. Sudden development of ischemic symptoms in previously
asymptomatic patients is a sign of embolus
Six Ps is the classic presentation acute arterial occlusion:
o Pain, Pallor, Poikilothermic, Pulselessness, Paresthesia, Paralysis
Other symptoms may include: [Show Less]