Complications of Diabetes Mellitus: Foot Ulcer

A 67-year-old woman with insulin-dependent diabetesmellitus and uncontrolled hyperglycemia complained offatigue and malaise. For 2 years, a draining ulcer hadbeen present on the bottom of her left foot.The patient had septicemia; blood cultures werepositive for Staphylococcus aureus. White blood cellcount was 16,000/μL; erythrocyte sedimentation rate,130 mm/h; and glucose level, 310 mg/dL.The patient was hospitalized; empiric therapy withcefazolin and gentamicin was started. The foot woundwas irrigated and debrided. The ulcer extended deeplythrough the first web space, dorsally to the skin surface,and into the entire great toe. Extensive necrotictissue was found. The patient's circulatory status wasvery poor; she had severe peripheral vascular compromise.Drainage portals were established. Cultures wereobtained.Despite the extensive irrigation and debridementand the continued antibiotic therapy, the ulcer did notimprove. A transmetatarsal amputation was performed.Initially, the patient's condition improved; however,necrotic tissue at the surgical site was extensive. Culturesgrew Proteus organisms, methicillin-resistantstaphylococci, enterococcus group D streptococci, Klebsiellaorganisms, and Morganella organisms. Ciprofloxacinand vancomycin replaced the initial antibiotic regimen;however, the patient's elevated blood urea nitrogenand creatinine levels precluded long-term therapy.Because the transmetatarsal amputation site beganto break down and the bacterial necrosis persisted despitecontinued antibiotic therapy, below-knee amputationwas scheduled. During surgery, swollen tissue, very paleand extremely poor vascularity, and the absence of musclecontractility were noted; above-knee amputation wasperformed. Dramatically compromised circulation and diminishedbleeding and muscle contractility were evidenteven at this level and at this distance from the ulcer.Within 2 days of the operation, the patient was talkativeand lively. The surgical site healed uneventfully.The patient was fitted for a prosthetic limb, and her glucoselevel was brought under control. She was verypleased with the outcome.