Table 2.

Severity classification of acute lower limb arterial occlusive disease

Class	Description/prognosis	Findings		Doppler signals
		Sensory loss	Muscle weakness	Arterial	Venous
I:Viable	Not immediately threatened	None	None	Audible	Audible
II:Threatened a:Marginal b:Immediate	Salvageable if promptly treated	Minimal (toes) or none	None	(Often) inaudible	Audible
	Salvageable with immediate revascularization	More than toes, associated with rest pain	Mild, moderate	(Usually) inaudible	Audible
III:Irreversible	Major tissue loss or permanent nerve damage inevitable	Profound, anesthetic	Profound, paralysis (rigor)	Inaudible	Inaudible