Older Woman With Nonhealing Foot Ulcer

A 67-year-old woman has had an ulcer on her left heel for at least several weeks.She applied a homemade dressing and cut her shoes to try to relieve pressureon the ulcer; however, in the past week, areas around the ulcer have becomepainful. These areas, as well as the dorsum of the foot, are red and swollen.
HISTORY
For about 11 years, the patient has had type 2 diabetes, which is managedwith metformin and glyburide. However, her compliance with therapy--particularlydietary restrictions--is poor; moreover, she checks her blood glucoselevel infrequently. She lives alone.
PHYSICAL EXAMINATIONAND IMAGING RESULTS
The patient is moderately obese. Temperature is 37.7^oC (100^oF); othervital signs are normal. A 1-cm-deep ulcer on the left heel is surrounded by atleast 4 cm of cellulitis; the dorsum of the same foot is warm and red. Althoughthe ulcer appears deep and of full thickness, a sterile surgical probe insertedin the wound does not touch bone (negative probe-to-bone test). The posteriortibial pulse is 11, but the dorsalis pedis pulse is undetectable. Proprioceptionand pain sensation in both feet are very diminished to absent. Radiographs ofthe foot reveal no changes that suggest osteomyelitis. Blood glucose level is210 mg/dL.Which of the following is the most appropriate management strategyfor this patient?A. Apply a total contact cast, instruct the patient in wound care, and adviseher to limit ambulation for 4 weeks.
B. Admit the patient and arrange for an immediate surgical consultation foreither revascularization or amputation.
C. Apply a total contact cast, instruct the patient in wound care, and prescribea 4-week course of cephalexin.D. Admit the patient and institute a strict non-weight-bearing regimen; initiatebroad-spectrum antibiotics pending culture results; and arrange for earlysurgical intervention for either debridement and drainage or amputation, asindicated.CORRECT ANSWER: D
This patient has one of the common and difficult-to-treatmorbidities associated with diabetes: foot disease with ulceration.In the United States, lower extremity morbidityresults in an estimated 80,000 amputations each year.¹The initial condition that eventuates in amputation isusually a skin ulcer. Diabetic ulcers develop when peripheralneuropathy results in loss of protective sensation andundetected trauma causes breakdown of the skin. Oncethe skin has broken down, concomitant infection andischemia exacerbate the pathology and interfere withhealing.² Most diabetic ulcers involve a combination of these factors--peripheral neuropathy, infection, and ischemia--each of which needs to be evaluated and treated.With comprehensive interdisciplinary management, upto 90% of ulcers can be healed.¹A variety of approaches have been used to treat diabeticulcers. Immediate surgery, specifically revascularization(choice B), is likely too aggressive for this patient.She obviously has an infection, as evidenced by bothlocal findings and her systemic temperature. Thus, evenif revascularization is eventually deemed necessary, itshould be postponed until the infection has beencontrolled.Conversely, outpatient management (choices A andC) is not aggressive enough. This patient meets severalof the accepted criteria for a limb-threatening infectionthat requires admission and inpatient care. These include:

• Deep ulceration.
• More than 2 cm of surrounding cellulitis.
• Lymphangitis.
• Bone involvement.
• Serious ischemia.³

Admission is also recommended for milder infectionsif home support is poor.

³

With a full-thickness ulcer surrounded by more than2 cm of cellulitis, this patient clearly meets the first 2 criteria.In addition, her self-care capabilities are unreliable andhome support is poor.Treatment of a limb-threatening infection consists ofhospitalization; nursing care with strict glycemic controland a non-weight-bearing regimen; empiric broad-spectrumantibiotic coverage pending results of appropriatecultures; and early surgical intervention--aggressive debridementand drainage initially and, if indicated, amputation(choice D).

^1,2

After this regimen is initiated, time forhealing is allowed; the patient can then be reevaluated. Ifthe wound has not started to heal, consider revascularizationor amputation.

Outcome of this case.

The patient was admitted andempiric antibiotic therapy with clindamycin and a fluoroquinolonewas started. Cultures revealed polymicrobial infectionwith

Proteus

species as well as anaerobes, all ofwhich were sensitive to the antibiotics given. She underwentmultiple surgical debridements and received skillednursing care, which included enforcement of a strictnon-weight-bearing regimen. Doppler ultrasonographyshowed claudication-level pulses below the knee.After a 2- to 4-week healing period, the patient will bereevaluated. The prognosis for salvage without amputationis guarded.

References:

REFERENCES:

1.

Caputo GM, Cavanagh PR, Ulbrecht JS, et al. Assessment and managementof foot disease in patients with diabetes.

N Engl J Med.

1994;331:854-860.

2.

Sumpio BE. Foot ulcers.

N Engl J Med.

2000;343:787-793.

3.

Joshi N, Caputo GM, Weitekamp MR, Karchmer AW. Infections in patientswith diabetes mellitus.

N Engl J Med.

1999;341:1906-1912.