Acute Limb Ischaemia (ALI)

 Rutherford's Classification of Peripheral Arterial Disease

Class	Category	Prognosis	Sensory loss	Muscle weakness	Arterial Doppler	Venous Doppler
I	Viable	No immediate limb threat	None	None	Audible	Audible
IIA	Threatened: marginal	Salvageable if treated promptly	Minimal-none	None	+/-Audible	Audible
IIB	Threatened: Immediate	Salvageable if treated immediately	More than just toes	Mild-moderate	Rare audible	Audible
III	Irreversible	Limb loss or permanent damage	Profound	Profound	None	None

-from the Society of Vascular Surgery/International Society of Cardiovascular Surgery (Rutherford et al, 1997)

1.      Usually thrombotic occlusions are class I or IIA and are treated with intra-arterial thrombolysis if symptom duration <14 days (especially if bypass graft occlusion) and if patient has significant co-morbidities/high operative risk.

2.      Usually embolic occlusions are class IIB or III.  They usually require surgery as thrombolytics take effect too slowly.