Vancomycin Dosing Strategy for the Treatment of Peritonitis in a Child on Automated Peritoneal Dialysis: A First Pediatric Case Report.

Background: Bacterial peritonitis is a common complication of peritoneal dialysis. In the absence of systemic signs of infection, adult guidelines recommend treatment with intraperitoneal vancomycin either as empiric coverage of gram-positive organisms or as targeted therapy. However, there is no guidance on how to administer vancomycin in children on automated peritoneal dialysis.

Case report: We report vancomycin pharmacokinetics upon intraperitoneal administration for the treatment of a Staphylococcus hominis peritonitis in an 11-year-old patient on automated nocturnal intermittent peritoneal dialysis. While the patient was hospitalized, vancomycin was administered intraperitoneally as a continuous treatment. After hospital discharge, the nocturnal peritoneal dialysis was resumed. In the absence of treatment guidelines, intraperitoneal vancomycin was initially administered empirically only during the nocturnal dialysis exchanges which led to repetitive subtherapeutic vancomycin plasma concentrations and the persistence of S. hominis in dialysate cultures. Based on studies in adults, the dosing strategy was subsequently modified to administer vancomycin at a dosage of 15 mg kg^-1 in the dialysate with a 6-h dwell period prior to the nocturnal dialysis thereby allowing to reach optimal peak concentrations. The dosing interval was subsequently individualized using therapeutic drug monitoring to ensure residual vancomycin concentrations > 10 mg L^-1 thereby leading to clinical and microbiological recovery.

Conclusions: This case presents a dosing strategy based on a comprehensive review of the literature and highlights that a sufficient dwell period is critical when treating pediatric patients on automated peritoneal dialysis in order to allow vancomycin distribution and equilibration between the dialysate and the plasma.