 On the study day, patients will arrive at the dialysis clinic, drain their peritoneal cavity and instill fresh dialysate by way of the PD catheter over 5 - 10 minutes using a Y-type administration set. Spent dialysate from the preceding exchange will be drained immediately prior to the intravenous injection of ertapenem. Patients with residual renal function will urinate immediately prior to administration of ertapenem. An aliquot 10 mL of urine will be saved and tested to ensure that no interfering substances are present that would invalidate the assay used for ertapenem determination in the urine. 