ToolsCalculators
WIfI (Wound, Ischemia, foot Infection) classification
Stratifies 1-year amputation risk in the threatened lower limb.
WIfI (Wound, Ischemia, foot Infection) classification
Wound / tissue loss grade
Extent of ulceration or gangrene.
Ischemia grade
Use ABI, or ankle/toe pressure or TcPO2 if ABI is unreliable.
foot Infection grade
Based on the IDSA/SVS foot-infection criteria.
ResultStage 1 - Very low risk
WIfI class W0 I0 fI0. Estimated 1-year amputation risk: very low. Higher-grade ischaemia and larger wounds identify limbs most likely to benefit from revascularisation.
- WIfI class
- W0 I0 fI0
- Clinical stage
- Stage 1 (Very low)
When to use
- Staging a threatened lower limb in chronic limb-threatening ischaemia or a diabetic foot, in patients with and without diabetes.
- Communicating amputation risk and gauging the potential benefit of revascularisation.
Formula
Grade wound (0-3), ischemia (0-3) and foot infection (0-3) independently. The three grades combine, via the Society for Vascular Surgery expert-consensus grid, into a clinical stage 1-4 corresponding to very low, low, moderate and high estimated 1-year amputation risk.
Pearls and pitfalls
- Ischemia and infection add to, but do not multiply, the amputation risk driven mainly by wound extent.
- The same paper provides a parallel grid estimating benefit from revascularisation; a limb can be high amputation risk yet also high revascularisation benefit.
- Restage after debridement, infection control and revascularisation, as the class often improves.