4. When osteomyelitis is present, bone cultures help to define the optimal antibiotic therapy. Recent studies have confirmed older data regarding the poor correlation between surface cultures and bone cultures. The latter are preferred, when feasible.
5. Consider revascularization. Most diabetic foot infections arise in the setting of vascular insufficiency. At a minimum, patients with diabetic foot infections should have ankle-brachial indices performed for screening. Because diabetics may have falsely elevated ankle pressures due to calcified and non-compressible arteries, additional diagnostic studies may be useful, such as segmental pressures and Doppler pulse volume recordings.
Measurement of the transcutaneous oxygen concentration (TcP02) has been recommended, particularly in assessing which patients may benefit from hyperbaric oxygen. However, the TcP02 is not widely available, and the benefit of hyperbaric oxygen in this setting remains controversial.
6. Patients should be educated in meticulous foot care to prevent recurrences and reinfections. A diabetic foot infection may indicate that the patient lacks the knowledge, resources, or motivation for proper foot care. It also suggests that something is seriously awry with the patient’s diabetic regimen, compliance, or both. Hospital admissions for diabetic foot infections provide an opportunity to revise the patient’s diabetic medications; to educate the patient regarding wound care, skin care, and daily foot self-examination; to provide additional resources such as visiting nurses; and to refer patients for podiatric care, including tailored shoes, orthotics, and, if necessary, casting to off-load ulcers. TH
Dr. Ross is an instructor in medicine at Harvard Medical School.
References
- Hill SL, Holtzman GI, Buse R. The effects of peripheral vascular disease with osteomyelitis in the diabetic foot. Am J Surg. 1999 Apr;177(4):282-286.
- Gordois A, Scuffham P, Shearer A, et al. The health care costs of diabetic peripheral neuropathy in the United States. Diabetes Care. 2003;26(6):1790-1795.
- Lazzarini L, Mader JT, Calhoun JH. Diabetic foot infection. In: Calhoun JH, Mader JT, eds. Musculoskeletal Infections. New York, NY. Marcel Dekker. 2003.
- Lipsky BA, Berendt AR, Deery HG, et al. Diagnosis and treatment of diabetic foot infections. Clin Infect Dis. 2004 Oct;39(7):885-910.