Hemodynamics/perfusion: Measure TP or TcPO₂ if ABI incompressible (>1.3)
SVS grades 0 (none), 1 (mild), 2 (moderate), and 3 (severe).

Grade: 3

Grade: 0
ABI
≥0.80
Ankle systolic pressure
>100 mm Hg
TP, TcPO₂
≥60 mm Hg
Grade: 1
ABI
0.6-0.79
Ankle systolic pressure
70-100 mm Hg
TP, TcPO₂
40-59 mm Hg
Grade: 2
ABI
0.4-0.59
Ankle systolic pressure
50-70 mm Hg
TP, TcPO₂
30-39 mm Hg
Grade: 3
ABI
≤0.39
Ankle systolic pressure
<50 mm Hg
TP, TcPO₂
<30 mm Hg

ABI, Ankle-brachial index; PVR, pulse volume recording; SPP, skin perfusion pressure; TP, toe pressure; TcPO₂, transcutaneous oximetry.
Patients with diabetes should have TP measurements. If arterial calcification precludes reliable ABI or TP measurements, ischemia should be documented by TcPO₂, SPP, or PVR. If TP and ABI measurements result in different grades, TP will be the primary determinant of ischemia grade.
Flat or minimally pulsatile forefoot PVR = grade 3.