Assessing tobramycin levels and renal function following the implantation of CaSO4 beads impregnated with tobramycin: A prospective cohort study

Abstract

This study aimed to evaluate the risk of serum tobramycin concentrations exceeding therapeutic levels after administration of calcium sulfate (CaSO 4 ) beads containing either 240 mg or 400 mg tobramycin and 1000 mg vancomycin. This single-center, prospective. This single-center, prospective study included included Piedmont Columbus, Regional orthopedic surgery patients. Following the implantation of tobramycin into CaSO 4 beads, serially measured serum tobramycin concentrations were evaluated after 6, 12, 24, and 48 hours. In addition to that, serum tobramycin concentration was evaluated after 5 days. None of the patients who received 240 mg tobramycin-impregnated beads had a tobramycin level >2 μg/mL. Six hours after implantation, the tobramycin level in 2 out of 2 (100%) patients who received 400 mg of tobramycin-impregnated beads was >2 μg/mL. One day following the surgery, the median serum creatinine was 0.85 mg/dL, with an interquartile range of 0.73 to 1.04 mg/dL. No cases of acute kidney injury were observed. This cohort demonstrated that non-nephrotoxic serum tobramycin levels could be achieved in CaSO 4 beads mixed with 240 mg or 400 mg of tobramycin.Abbreviations: CaSO 4 = calcium sulfate, POD = postoperative day, SD = standard deviation.