糖尿病足部傷口的定性評估方法。SVS WIFI Classification

安南醫院 高壓氧中心 游朝慶醫師

   因為在血管介入領域常用的周邊動脈阻塞程度評估The Fontaine and Rutherford classifications^1,2，其並無法用來評估糖尿病患者的血管病變，如其常用的『危急性肢體缺血』(critical limb ischemia;. CLI)³這名詞為周邊動脈疾病(peripheral artery disease; PAD)的一種嚴重臨床表現，然而在有神經病變的糖尿病患者卻無法感受到這種肢體疼痛。故Fontaine and Rutherford classifications早已明訂其並不能用來評估糖尿病患者，且此方法也只能評估缺血ischemic狀態，沒有描述到傷口狀況及感染程度。而常用的 Wagner system沒有描述到動脈阻塞的嚴重程度，以及由感染導致的組織壞疽。而德州大學分類系統The University of Texas system 並沒有將動脈阻塞以及感染做更進一步的分級⁴。
    因此在2014年，美國血管外科學會（The Society for Vascular Surgery）的下肢臨床指引委員會 （Lower Extremity Guidelines Committee），將傷口Wound,血循Ischemia及足部感染Foot Infection (WIfi)這三項容易導致截肢的因素各分為四級（用0-3四個分數評分），稱為SVS危及下肢分類系統SVS Lower Extremity Threatened Limb Classification，簡稱WIFI Classification⁵。，

表1.W: Wound/clinical category

Grade	Ulcer	Gangrene
0	No ulcer,. Ischemic rest pain，可以有休息疼痛但沒有傷口	No gangrene無壞疽
1	Small, shallow ulcer(s) on distal leg or foot; no exposed bone, unless limited to distal phalanx輕微組織缺損< 5 cm2，無骨頭露出除非在指頭末端	No gangrene無壞疽
2	Deeper ulcer with exposed bone, joint or tendon; generally not involving the heel; shallow heel ulcer, without calcaneal involvement傷口 5-10 cm2深及骨頭、關節及韌帶，但不含腳傷口或跟骨	Gangrenous changes limited to digits指頭有壞疽
3	Extensive, deep ulcer involving forefoot and/or midfoot; deep, full thickness heel ulcer ± calcaneal involvement大且深的傷口> 10 cm2 ，侵犯前足或中足，整層皮膚壞死，可深及跟骨	Extensive gangrene involving forefoot and /or midfoot; full thickness heel necrosis ± calcaneal involvement，前足或中足廣泛壞疽，整層皮膚壞死，可深及跟骨

表2.I: Ischemia

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

若ABI>1.3，則改評估TP, toe pressure腳趾血壓或TcPO2, transcutaneous oximetry.Measure
若患者有糖尿病，則需追加評估TP腳趾血壓
若有動脈硬化，則需評估TcPO2, SPP, skin perfusion pressure;, or PVR , pulse volume recording
若ABI和TP結果不一樣，則以TP優先
表3. fI: foot Infection:
SVS採用Infectious Diseases Society of America (IDSA) 及International Working Group on the Diabetic Foot (IWGDF) perfusion, extent/size, depth/tissue loss, infection, sensation (PEDIS) classifications of diabetic foot infection的感染分級方法⁶

Clinical manifestation of infection	SVS	IDSA/PEDIS infection severity
No symptoms or signs of infection無感染	0	Uninfected
Infection present, as defined by the presence of at least 2 of the following items:至少有下列兩種以上 • Local swelling or induration腫 • Erythema >0.5 to ≤2 cm around the ulcer紅 • Local tenderness or pain痛 • Local warmth熱 • Purulent discharge髒的滲液 (thick, opaque to white, or sanguineous secretion) _________________________________________________________ 只有表皮的局部發炎	1	Mild
Local infection (as described above) with erythema紅 >2 cm, or involving structures deeper than skin and subcutaneous tissues筋骨處有膿或發炎但無全身症狀 (eg, abscess, osteomyelitis, septic arthritis, fasciitis), and No systemic inflammatory response signs (as described below)	2	Moderate
Local infection (as described above) with the signs of SIRS, as manifested by two or more of the following: 除了局部感染還有全身SIRS症狀如 • Temperature >38° or <36°C發燒 • Heart rate >90 beats/min心跳快 • Respiratory rate >20 breaths/min or PaCO2 <32 mm Hg喘 • White blood cell count >12,000 or <4000 cu/mm or 10% immature (band) forms白血球高	3	Severe

這WIFI分類評分下來可得到3種分數，可用來作為評估一年內的截肢率以及是否需要做血管介入（如表4），
表4. a表一年內的截肢風險, b表需血管介入的急迫性

遺憾的是，這方法的評分並非是將三種分數相加，而是要查表，如下表，並因而將之分為四期，個人認為雖然看起來專業一點，但是和德州大學系統一樣，不好記，也不好分期。
表5. 分期

Risk of amputation	Proposed clinical stages	WIfI spectrum score (W,I, fI)
Very low	Stage 1	000, 001, 010, 011, 100, 101, 110
Low	Stage 2	002, 011, 020, 021, 030, 102, 111, 120, 200, 201
Moderate	Stage 3	003, 021, 022, 031, 032, 103, 112, 121, 130, 131, 202, 210, 211, 220, 300, 301
High	Stage 4	013, 023, 033, 113, 122, 123, 132, 133, 203, 212, 213, 221, 222, 223, 230, 231, 232, 233, 302, 303, 310, 320, 330, 321, 323, 331, 332, 333

若沒有下面這種工具(圖1)，，實在不好記憶，好在隨著智慧手機app的普及，SVS也推出了app在google play商店打入SVS iPG，這app裡面就有Wifi classification System 計算工具(圖2)，，但終究，這只是一個定性的評分工具，並不是定量的評分工具，只是想要用這複雜的系統取代目前全世界通用，簡單好用的Wagner系統，但同樣都能達到預測截肢率。不過這套系統畢竟是美國血管外科學會所推的，對於血管的評估方式很是專精，值得參考。

圖1.WIFI速查工具

圖2. Wifi classification System計算工具App

1. Fontaine R, Kim M, Kieny R. Surgical treatment of peripheral circulation disorders. Hely Chir Acta. 1954;21(5–6):499-533.
2. Rutherford RB, Baker JD, Ernst C, et al. Recommended standards for reports dealing with lower extremity ischemia: revised version. J Vasc Surg. 1997;26(3):517–38.
3. Jamieson C. The definition of critical ischaemia of a limb. Br J Surg 1982; 69(suppl): S1
4. Oyibo SO, Jude EB, Tarawneh I, et al. A comparison of two diabetic foot ulcer classification systems: the Wagner and the University of Texas wound classifications systems. Diabetes Care. 2001;24(1):84-8.
5. Mills JL, Conte MS, Armstrong DG, et al. The Society for Vascular Surgery Lower Extremity Threatened Limb Classification System: Risk stratification based on Wound, Ischemia, and foot Infection (WIfI). J Vasc Surg. 2014;59(1):220034.e1-2. http://www.sciencedirect.com/science/article/pii/S0741521413015152#
6.糖尿病足部傷口的定性評估方法。PEDIS分類 供研究之用的糖尿病足部傷口的分類方法，及IDSA-IWGDF的感染分類系統
http://woundmaster.blogspot.tw/2011/12/pedis.html