Lower Extremity Infections Research Articles

Therapy of lower extremity infections with ciprofloxacin in patients with diabetes mellitus, peripheral vascular disease, or both

PURPOSE: Lower extremity infections in the presence of vascular insufficiency are difficult and costly to treat. Few well-controlled clinical trials evaluating the management of these infections exist. We decided to investigate the ability of a new fluoroquinolone, ciprofloxacin, to reduce the morbidity associated with these infections and the amount of in-hospital time required for the administration of antibiotic therapy. PATIENTS AND METHODS: Forty-eight patients with peripheral vascular disease (46 with diabetes mellitus) who presented to the hospital for treatment of lower extremity infections were randomized in a blinded fashion to receive oral ciprofloxacin at a dosage of either 750 mg or 1,000 mg twice daily. Patients with osteomyelitis received three months of therapy and those with infections limited to soft tissues, three weeks of ciprofloxacin treatment. All subjects were followed for one year. RESULTS: One patient received an amputation 24 hours after enrollment, and two patients discontinued therapy after 20 and 37 days because of adverse effects and were not evaluable. At the one-year follow-up, 27 of the 45 (60 percent) evaluable patients had a fully successful outcome defined as not requiring either repeat antimicrobial therapy for their initial infection or amputation of the involved extremity. In the group of 18 patients in whom therapy failed, a total of only nine amputations were required. In the 15 patients whose lesion closed during therapy, 93% (14 patients) experienced a long-term successful outcome. CONCLUSION: Treatment with this new fluoroquinolone offers promise for the improved outcome of patients with the serious infectious complication of infected lower extremity ulcerations in peripheral vascular disease, diabetes mellitus, or both.

Control of infection in the diabetic foot: the role of microbiology, immunopathology, antibiotics, and guillotine amputation.

Newer culture techniques have demonstrated that diabetic foot infections are polymicrobial, involving both anaerobic and aerobic bacteria. These infections are characteristically foul-smelling and create immense tissue destruction. Occasionally, despite the absence of clostridial organisms, subcutaneous gas may be present. The importance of adequate surgical debridement has been emphasized. In the event of advancing, unremitting infection involving the foot, ankle guillotine amputation may be a life-saving technique. Finally, the role of host-defense mechanism in diabetes is important. Polymorphonuclear leukocyte chemotaxis and phagocytosis are energy-dependent processes that are deficient in the diabetic. Better diabetic control with maintenance of normal blood sugars and avoidance of ketoacidosis may be the key to prevention of these morbid, lower extremity infections.

Guillotine amputation in the treatment of nonsalvageable lower-extremity infections.

Primary definitive amputation performed in the presence of distal-extremity infection carries the risk of wound infection and additional limb loss. We reviewed 75 below-knee amputations performed for nonsalvageable foot infections. Patients were retrospectively divided into two groups: group 1 underwent open ankle guillotine amputation followed by definitive below-knee amputation, and group 2 underwent primary definitive below-knee amputation. In group 1, 97% of patients achieved primary healing after revision, and none required amputation at a higher level. In group 2, 78% of patients achieved primary healing, but 11% required revision of the amputation to the above-knee level. These data supported the following conclusion: guillotine ankle amputation followed by below-knee amputation for the nonsalvageable, infected lower extremity is associated with a significantly lower amputation failure rate than primary definitive amputation.

The Fetid Foot: Lower-Extremity Infections In Patients with Diabetes Mellitus

Infections of the lower extremities in patients with diabetes mellitus have been attributed to Staphylococcus aureus and other facultatively anaerobic bacteria. However, a review of 30 consecutive diabetics who required surgery for lower-extremity infections revealed that 17 had mixed infections due to both obligate and facultative anaerobes; only six had infections due to S. aureus. Mixed infections often had characteristics of anaerobic suppuration and responded poorly to therapy. Patients with mixed infections required more operations than did those with staphylococcal infections, and their surgical wounds healed more slowly. Seven patients had infections with mixed enteric bacteria (neither anaerobes nor S. aureus), and their response to therapy was intermediate between that of the patients with mixed anaerobic infections and those with staphylococcal infections. Nine additional patients with mixed anaerobic infections were treated with cefoxitin; three required amputations at a level above the ankle, but six patients improved and required only limited surgery that preserved foot function. Bacteroides fragilis was the anaerobe isolated most often. Cefoxitin (less than or equal to 20 micrograms/ml) inhibited all of the anaerobes isolated from the nine patients and 97% of an additional 135 consecutive clinical isolates of B. fragilis; 98% of 54 strains of Bacteroides oralis and all of 34 strains of Bacteroides melaninogenicus were also inhibited. These in vitro results and the results of our clinical study show that cefoxitin is a promising antibiotic for therapy of foot infections due to a mixed flora of anaerobes in diabetics.