A 42-year-old male patient with type-2 DM (T2DM) presented to our emergency room (ER) in October 2018 with a soft tissue infection on the left foot sixteen days after a penetrating plantar injury caused by a piece of glass. He had sought the ER ate the same day as the plantar puncture wound and was submitted to surgical removal of the fragment of glass. Days before his first visit to the ER, he was barefoot in a muddy soccer field with rubbish and dog feces. Because of the small-fiber neuropathy, he did not notice the glass after the game. This penetrating injury likely occurred during the game practice since he was not barefoot at another time in the last few days. Two days after the trauma, the patient presented to the ER with intense pain, erythema and swelling on the plantar site. Then, the emergency physician prescribed a seven-day course of amoxicillin/clavulanate 875/125 mg PO BID plus ciprofloxacin 500 mg PO BID. Then, as there was no clinical improvement, the patient sought medical care for the third time and was hospitalized for evaluation by the vascular surgery team (VST). The wound was categorized as PEDIS 3 infection severity (PEDIS, P = perfusion, E = extent/size, D = depth/tissue loss, I = infection, S = sensation). The PEDIS 3 grade means a moderate infection; it extends under subcutaneous tissue, or erythema surpasses a 2-cm rim over the ulcer, and there are no systemic signs of infection 5.
On general examination, the mental status of the patient was preserved, the systemic blood pressure was 130/80 mm Hg, the heart rate was 97/min, the temperature was 36.4°C, and the respiratory rate was 16/min; the body mass index (BMI) was > 30 kg/m2. Laboratory tests at admission showed hemoglobin = 12.4 g/dL, white cell count = 10.700/mm3 (neutrophils, 73.2%; eosinophils, 1.9%; lymphocytes, 20.4%; monocytes, 4.2%), platelets = 304 x 103/mm3, glycemia = 119 mg/dL, creatinine = 0.72 mg/dL, and BUN = 10.27 mg/dL. Based on the abovementioned parameters, the VST decided on surgical approach: they performed a debridement and a decompressive fasciotomy; the main intraoperative findings were the presence of a mild and thick exudate, friable tissue, and inflammatory signs restricted to aponeurosis. Afterward, the VST started clindamycin 600 mg IV q6 h and ciprofloxacin 400 mg IV q12 h, but a new debridement was necessary due to the lack of clinical improvement – during the new operation, the infection was still restricted to the aponeurosis level.
Due to therapeutic failure after hospital admittance, an infectious disease clinic was consulted, and the VST started piperacillin/tazobactam 4.5 g IV q6/6 h in a 4-hour extended infusion (EI). After forty-eight hours, inflammation signs persisted. Then, an additional surgical approach was needed; right at that time, soft tissue culture results from the first surgical procedure came back, with the identification of Burkholderia cepacia group (VITEK® 2), which was only susceptible to meropenem (minimum inhibitory concentration (MIC) = 2, VITEK® 2), according to the Clinical and Laboratory Standards Institute (CLSI) on Antimicrobial Susceptibility Testing published in 2018 6. We then prescribed meropenem at 2 g IV q6 h in 3-hour EI after considering MIC = 2, BMI > 30 kg/m2, and microangiopathy as an impediment to reach a high probability of target attainment (PTA).
After 24 hours of the onset of meropenem, clinical improvement was evident. To check damaged tissue not accessible in previous surgical procedures, MRI of the foot was performed, and signs of osteomyelitis of the phalanges of the 3rd and 4th fingers, in addition to ulcerations and fistulous paths of the cutaneous, subcutaneous, and deep myoadipose tissues in the plantar region of the ante foot, were identified. Even so, we chose conservative treatment with 14 days of meropenem. At the end of the first year of follow-up, mild infections occurred, but amputation was not needed.