prevention of diabetic foot ulcers and lower extremity amputation barry stults, m.d. scott clark,...

PREVENTION OF DIABETIC FOOT ULCERS AND LOWER EXTREMITY AMPUTATION

Barry Stults, M.D.

Scott Clark, D.P.M

Thomas Miller, M.D.

University of Utah Medical Center

©2006. American College of Physicians. All Rights Reserved.

CASE: Mr. M.C.

• 64 yr-old obese white male, not seen x 12 mo

• Type 2 DM (15 yrs)

BP (18 yrs)

Dyslipidemia (18 yrs)

CABG (10 yrs ago)

Claudication (today; 25 yds)

• Insulin/Metformin/Statin/ARB/Hctz/CCB/ASA

• “Sore on my left foot, Doc”


CASE: Mr. M.C.

• Clinical evaluation of heel ulcer:– Probe reached bone

– Extensive subcutaneous abscess

• MRI: extensive osteomyelitis

• ABI: 0.2

• Angiography: severe infrapopliteal, suprapopliteal obstruction– Not amenable to revascularization

• Uncontrolled infection despite antibiotics/drainage


AMPUTATIONS IN DIABETES

Common:• Worldwide – amputation 2 to diabetes q 30 sec.• U.S.A. – 80,000 amputations/y (2002)

– Higher rates in men, racial/ethnic minorities

Costly:• $60,000/amputation• $2 billion/y total costs

Lancet 2005; 366:1719 Diabetes Care 2004; 27:1598 Diabetes Care 2003; 26:495


AMPUTATIONS IN DIABETES

Tragic: “Rule of 50”• 50% of amputations transfemoral/transtibial level

• 50% of patients 2nd amputation in 5y

• 50% of patients Die in 5y

Clinical Care of the Diabetic Foot, 2005


FOOT ULCERS IN DIABETES

Precipitate 85% of amputations: “Rule of 15”• 15% of diabetes patients Foot ulcer in lifetime

• 15% of foot ulcers Osteomyelitis

• 15% of foot ulcers Amputation

Clinical Care of the Diabetic Foot, 2005


FOOT ULCERS IN DIABETES

Costly:• $30,000/ulcer• $9 billion/y total costs

Tragic:• Quality of life: ulcer patient amputation patient

– Burden of non-weight-bearing as ulcer heals– Lifetime behavioral adaptations to prevent recurrence– Fear of recurrent ulcer/amputation

• 70% ulcer recurrence in 3y

Foot Ankle Int 2005; 26:32, 128 Clin Infect Dis 2004; 39(Suppl 2):S129


TEAM CARE REDUCES ULCERS/AMPUTATIONS

Five clinical trials:

• Format: integrated, risk-stratified interventions– ID high-risk patients with exam:

• Frequent follow-up to detect early problems

• Educate/motivate self-care behaviors

• Prophylactic nail/skin care by podiatry

• Therapeutic footwear, if needed

– Prompt, multidisciplinary Rx of ulcersLancet 2005; 366:1676


TEAM CARE REDUCES ULCERS/AMPUTATIONS

Efficacy of team care:– 50-80% reductions in ulcers/amputations

• Economic modeling studies of team care:– Cost-effective if 25-40% reduction in ulcer rate– Cost-saving if > 40% reduction in ulcer rate

Applicable only to high-risk patients

Lancet 2005; 366:1719 Diabetes Care 2004; 27:901


Sensory Joint Motor Autonomic PAD

Neuropathy Mobility Neuropathy Neuropathy

Protective Muscle atrophy and Sweating Ischemia

sensation 2° foot deformities 2° dry skin

Foot pressure Foot pressure Fissure HealingMinor trauma esp. over recognition bony prominences

Callus Pre-ulcer ULCER Infection AMPUTATION

Minor Trauma: Interdigital Maceration

Mechanical (Moisture, Fungus)

Chemical

Thermal

PATHOGENESIS OF DIABETIC FOOT ULCER AND AMPUTATION


OTHER RISKS FOR ULCER/AMPUTATION

Failure to adequately care for the feet:– Inadequate patient education– Inadequate patient motivation

• Depression, anxiety, anger more common in diabetes

– Physical disability• Cannot see feet 2 to retinopathy

• Cannot reach feet 2 to obesity, age (?50% of patients)

– Limited access to podiatry services

Age Ageing 1992; 21:333 Diabetes Care 2003; 29:495 Diab Metab Res Rev 2004; 20(Suppl 1):S13


CAUSAL PATHWAYS FOR FOOT ULCERS % Causal Pathways

NEUROPATHY Neuropathy: 78%

Minor trauma: 79%

DEFORMITY Deformity: 63%

Behavioral issues ?

MINOR TRAUMA

- Mechanical (shoes) POOR SELF-

- Thermal FOOT CARE

- Chemical

ULCER

Diabetes Care 1999; 22:157


DETECTING FEET-AT-RISK• History:

– Prior amputation– Prior foot ulcer– PAD: known or claudication at < 1 block

• Exam:– Insensate to 5.07/10g monofilament– Major foot deformities– PAD

• Absent DP and PT pulses• Prolonged venous filling time• Reduced Ankle-Brachial Index (ABI)

– Pre-ulcerative cutaneous pathologyArch Intern Med 1998; 158:157


RISK STRATIFY FOR FOOT ULCERATION

Foot Ulcer, % Office PatientsRisk Level %/yr (diabetes clinics)3: prior amputation 28.1% 7% prior ulcer 18.6%

2: insensate 6.3% 10% and

foot deformity or

absent pedal pulses

1: insensate 4.8% 17 - 30%

0: all normal 1.7% 66%

Diabetes Care 2001; 24:1442 Diabetes Metab 2003; 29:261


ANNUAL DIABETIC FOOT EXAMS2000 Behavioral Risk Factor Surveillance System, CDC

Total

Private

Insurance

Medicaid-

Medicare VA Uninsured

% with foot

exam in

past year

63 64 65 84* 48*

*p < 0.01

Health Services Research 2005; 40:361


PHYSICAL EXAMINATION OF THE FEET IN PERSONS WITH DIABETES


SENSORY NEUROPATHY IN DIABETES

• Loss of protective sensation in feet– Sensory loss sufficient to allow painless skin injury

• Major risk factor for foot ulcer in diabetes• Detect with 5.07/10g Semmes-Weinstein monofilament

– Prevalence of insensate feet to 10g monofilament:• Age > 40y: 30% of diabetic patients• Age > 60y: 50% of diabetic patients

• Up to 50% have no neuropathic symptoms

Diabetes Care 2006; 29(Suppl 1):S24 Diabetes Care 2004; 27:1591


UTILITY OF MONOFILAMENT TESTING

Predicts ulcer/amputation in 5 prospective studies:• NPV (normal sensing) = 90-98%

PPV (fail to sense) = 18-36%• Prospective 32 mo observational study:

– 80% of ulcers/100% of amputations in insensate feet

• Superior predictive value to other tests:– Pin prick, cotton wisp, symptoms– ? 128 Hz tuning fork?

• ADA recommendation, 2006: also test vibration

Diabetes Care 2006; 29(Suppl 1):S25 J Fam Pract 2000; 49:S30 Diabetes Care 1992; 15:1386


USING THE 5.07/10gm MF (Tool-Kit)

• Demonstrate sensation on the forearm or hand

• Place monofilament perpendicular to test site

• Bow into C-shape for one second

• Test four sites/foot: Predicts 95% of ulcer formers vs. 8 sites

• Heel testing does not discriminate ulcer formers

• Avoid calluses, scars, and ulcers


USING THE 5.07/10g MF (Tool-Kit)

• Minimize bias:– Test sites in random sequences

– Test each site X3, sham test as 1 of 3

• Do you feel it? Yes or No?• Retest site if patient fails (misses 2/3 responses)• Insensate at 1 site = insensate feet• Falsely insensate with edema, cold feet• Test annually when sensation normal• Use < 100x/d; replace if bent; replace q 3 mo.• Purchase calibrated MF (See Tool-Kit)


PAD IN DIABETES

• Prevalence (ABI < 0.9): 20-30%– 10-20% in type 2 diabetes at Dx

– 30% in diabetics age 50y

– 40-60% in diabetics with foot ulcer

• Complications:– Claudication and functional disability

– Increases risk for concurrent CAD and CVD

– Delays ulcer healing• Increases amputation risk

• Not increase foot ulcer risk

JACC 2006; 47:921 Diabet Med 2005; 22:1310 Diabetes Care 2003; 26:3333


HX TO DETECT PAD IN DIABETES

• Claudication at < 1 block suggests severe ischemia

Vascular Level Site of Pain

Aorto-iliac Buttocks/Thigh

Femoral Calf

Tibioperoneal Foot/Ankle

• Rest pain indicates critical ischemia– Toes and forefoot

– Difficult to distinguish from neuropathic pain


(After Pompogelli and Campbell, 2002)

Ischemic Rest Pain

Unilateral (usually)

Continuous; hs With dependency

Absent DP/PT pulses

Neuropathic Pain

Bilateral (usually)

Wax/wane

No change with dependency

Variable DP/PT pulses




• Asymptomatic, severe PAD common in diabetes– Tibio-peroneal disease predominance:

• Unrecognized ankle/foot claudication

• No claudication

– Sensory neuropathy blunts/eliminates pain sensation of claudication and rest pain



EXAM TO DETECT PAD IN DIABETES

• Pedal pulse exam:– Absent DP and PT: LR = 3.0-3.8 for severe PAD– Absent DP or PT not predict PAD

• Non-palpable DP (8%) or PT (3%) in normals

– Present DP and PT not R/O PAD!• 30% with PAD have one palpable pulse (collaterals)

• High PAD suspicion vascular testing– Claudication, foot ulcer

JAMA 2006; 295:536 Arch Intern Med 1998; 158:1357 Diabetes Care 2003; 26:3333



• Venous filling time– Technique:

• Sitting: ID pedal vein bulging above skin

• Supine: Elevate leg to 45° for 1 min

• Sitting: time to pedal vein bulging above skin

J Clin Epidemiol 1997; 50:659 Arch Intern Med 1998; 158:1357



• Venous filling time

– Filling time > 20 sec predicts ABI < 0.5• Sensitivity = 22%; Specificity = 94%; LR = 3.9

J Clin Epidemiol 1997; 50:659 Arch Intern Med 1998; 158:1357


OTHER EXAM FINDINGS FOR PAD

• Helpful:– Femoral bruit (LR = 4.7–5.7)– Unilateral cool extremity

• Not predictive of PAD:– Atrophic skin– Hair loss– Capillary refill > 5 sec

Diabetes Med 2005; 22:1310 Arch Intern Med 1998; 158:1357


VASCULAR LAB TO DETECT PAD

• Ankle/Brachial BP Index or ABI Testing– Screening: 2004 ADA recommendation

• “Consider” at age 50 and q 5 yr• Screen earlier if multiple CVD risks

– Diagnosis:• Claudication, absent DP/PT pulses, foot ulcer

– Limitations:• Underestimate severity if medial artery Ca++

• Consider pulse volume recording, systolic toe BP, vascular consultation if uncertain about PAD

Diabetes Care 2005; 28:2206 Diabetes Care 2004; 27(Suppl 1): S15-S35


INTERPRETATION OF THE ABI

ABINormal 0.91-1.30Mild obstruction 0.71-0.90

*Moderate obstruction 0.41-0.70 *Severe obstruction 0.40

**Poorly compressible >1.30 2° to medial Ca++

*Poor ulcer healing with ABI 0.50 **Further vascular evaluation needed


MOTOR NEUROPATHY AND FOOT DEFORMITIES

• Hammer toes

• Claw toes

• Prominent metatarsal heads

• Hallux valgus

• Collapsed plantar arch


From Levin and Pfeifer, The Uncomplicated Guide to Diabetes Complications, 2002

• Hammer Toes

• Claw Toes


From Levin and Pfeifer, The Uncomplicated Guide to Diabetes Complications, 2002

Hallux Valgus


From Boulton, et al Diabetic Medicine 1998, 15:508


PRE-ULCER CUTANEOUS PATHOLOGY

Neuropathy inappropriate footwear:– Persistent erythema after shoe removal– Callus– Callus with subcutaneous hemorrhage: “pre-ulcer”

Autonomic neuropathy and secondary dry skin:– Fissure ulceration– Augment callus formation

Poor self-care of the feet:– Interdigital maceration with fungal infection– Nail pathology


RISK-STRATIFIED FOOTCARE MANAGEMENT FOR DIABETES PATIENTS


LOW RISK: CATEGORY 0 PATIENTS

• Annual comprehensive foot examination– Questionnaire completed by patient in waiting room– Examination form with decision-support

(See Tool-Kit)

• Every visit visual inspection if higher risk– Racial/ethnic minorities; alcoholism; homeless

• Basic education: self-management, appropriate footwear– Brief counseling– Written handout

JAMA 2005; 293:217


HIGH RISK: CATEGORY 1-3 PATIENTS

• Annual comprehensive foot exam

• Inspect feet at every office visit

• Podiatry care stratified to risk level

• Intensive patient education

• Detect/manage barriers to foot care

• Therapeutic footwear, if needed



Nursing tasks to facilitate foot exams:– “High Risk Feet” stickers to each chart (Tool-Kit)

– Remove patient’s shoes/socks• Increases % of foot exams in observational studies

– Determine that patient can reach/see soles of feet

– Stock 10g monofilament in each room• Consider training to perform 10g monofilament exam

– Provide patient education forms• Literacy/language appropriate

Diabetes Care 1983; 6:499 J Gen Intern Med 2003; 18:258


www.ndep.nih.gov/diabetes/pubs/feet_kit_Eng.pdf


http://www.ndep.nih.gov/diabetes/pubs/feet_kit_Eng.pdf


Regular prophylactic podiatry care:– Provide nail and skin care– Assess footwear needs– RCT: 48% RRR for recurrent ulceration– Optimal visit frequency not evidence-based:

Category 1 q 3-6 mo

Category 2 q 2-3 mo

Category 3 q 1-2 mo

Diabetes Care 2003; 26:1691 J Fam Practice 2000; 49(Suppl):S30



Intensive patient education:– 1 care clinician, podiatrist, educator contribute– Reinforce frequently – low retention documented– Patient to demonstrate self-care knowledge

• Questionnaires, tests are available (see Tool-Kit)

– Utility:• ? Reduced foot ulcer/amputation rates?

Cochrane Database Syst Rev 2005 Jan 25;(1)CD001488 Foot Ankle Int 2005; 26:38


BASIC FOOT CARE CONCEPTS

• Daily foot inspection– May require mirror, magnification, or caregiver– Educate patient to recognize/report ASAP:

• Persistent erythema

• Enlarging callus

• Pre-ulcer (callus with hemorrhage)



• Commitment to self-care:– Wash/dry daily

• Avoid hot water; dry thoroughly between toes

– Lubricate daily (not between toes)– Debride callus/corn to reduce plantar pressure 25%

• Avoid sharp instruments, corn plasters

– No self-cutting of nails if:• Neuropathy, PAD, poor vision



• Protective behaviors:– Avoid temperature extremes– No walking barefoot/stocking-footed– Appropriate exercise if sensory neuropathy

• Bicycle/swim > walking/treadmill

– Inspect shoes for foreign objects– Optimal footwear at all times


FOOT CARE EDUCATION TOOLS

• “Prevent diabetes problems: Keep your feet and skin healthy” Cartoons – minimal text – still simple www.niddk.nih.gov or [email protected]

• “Take Care of Your Feet For a Lifetime” – booklet Few cartoons – more advanced http://ndep.nih.gov/materials/pubs/feet/brochure/index.htm

• “Take Care of Your Feet For a Lifetime” – 1 page summary www.ndep.nih.gov/diabetes/pubs/FootTips.pdf


http://www.niddk.nih.gov/

mailto:[email protected]

http://ndep.nih.gov/materials/pubs/feet/brochure/index.htm

http://www.ndep.nih.gov/diabetes/pubs/FootTips.pdf

FOOT CARE EDUCATION TOOLS

“Diabetic Foot Care”– American Orthopedic Foot and Ankle Society– Multilingual translation

• Available in 20 languages

– Reference:

Trepman E, et al. Foot and Ankle International 2005; 26:64-107.


EDUCATIONAL DEFICIENCIES: HIGH RISK PATIENTS

• 558 high risk patients:

Deficiency % Deficient

Not inspect feet regularly 50%

Walk barefoot/stockings 62%

Seldom/never test water temp. 40%

Trim callus with sharp object 48%

Not know to call ASAP for foot ulcer 58%

Not know how to select footwear 57%

From GE Reiber, 2003©2006. American College of Physicians. All Rights Reserved.

BASIC FOOTWEAR EDUCATION

Avoid:

Pointed-toes

Slip-ons

Open-toes

High heels

Plastic

Black color

Too small

Favor:Broad-round toesAdjustable (laces, buckles,

Velcro)Athletic shoes, walking shoesLeather, canvasWhite/light colors½” between longest toe and

end of shoe

Diabetes Self-Management 2005; 22:33


THERAPEUTIC FOOTWEAR: GOALS

• Inappropriate footwear:– Contributes to 21-76% of ulcers/amputations

• Optimal footwear should:– Protect feet from external injury

– Reduce plantar pressure, shock and shear forces

– Accommodate, stabilize, support deformities

– Suitable for occupation, home, leisure

Diabetes Care 2004; 27:1832 Diab Metab Res Rev 2004; 20(Suppl1):S51


THERAPEUTIC FOOTWEAR: COMPONENTS

• Padded socks (eg. CoolMax, Duraspun, others)– Cushion metatarsal heads, heels, and decrease plantar

pressure– White, seamless, absorbent acrylic fibers

• Shoe inserts/insoles (closed-cell foam, viscoelastic)– Off-the-shelf– Custom-molded

• Therapeutic shoes– Extra-depth extra-width– Rigid rocker outsoles– Custom-molded


FOOTWEAR RECOMMENDATIONS BY RISK LEVEL

Low Risk (0) Proper style/fit, cushioned stock shoes

Sensation (1) Deep toe box shoes, cushioned insoles

Callosities, ulcer Hx Extra-depth stock shoes, custom-molded insole

Severe deformities Custom-molded extra-depth shoes and insoles, rigid rocker outsoles

Modified from The Foot in Diabetes, 2000, p.136©2006. American College of Physicians. All Rights Reserved.

THERAPEUTIC FOOTWEAR: EFFICACY

• Decreases plantar pressure 50-70%• Uncertain reduction in ulcer rate:

– 1 prevention: no data

– 2 prevention: controversial reduction of ulcer recurrence• Analytic/descriptive studies decreases ulcers 50-75%

• 2 RCTs no benefit

• Benefits vary with footwear use, risk level?– Severe foot deformity, prior toe/ray amputation?



MEDICARE COVERAGE OF THERAPEUTIC FOOTWEAR

• Certify diabetic patient with foot-at-risk

– 1° care physician

• Prescribe therapeutic footwear

– D.P.M., D.O., M.D.

• Prepare/fit therapeutic footwear

– Pedorthist, orthotist, prosthetist, D.P.M.• www.cpeds.org

Foot Ankle Int 2005; 26:42


http://www.cpeds.org/

MEDICARE COVERAGE OF THERAPEUTIC FOOTWEAR• Medicare pays 80% of payment amount allowed:

Total Amount Amount Covered by Allowed Medicare

Extra Depth shoes $132.00 $105.60Custom-made shoes $396.00 $316.00Diabetic Pre-fab Insoles $67.00 $53.60Diabetic Custom Insoles $67.00 $53.60

1 pair extra-depth shoes 3 pair insoles/y, or1 pair extra-depth shoes with modification 2 pair insoles/y, or1 pair custom-molded shoes 2 pair insoles/y


prevention of diabetic foot ulcers and lower extremity amputation barry stults, m.d. scott clark,...

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