How a Patient Survived Hemodialysis (HD) Using Unprocessed City Water

Introduction: A 46 Y/O female with aortic valve (AV) endocarditis and AKI on CKD received HD using unprocessed city water to prepare dialysate. Case Description: A 46 Y/O homeless female with stage 4 CKD and long standing history of IV drug abuse was admitted with a Temp of 38.2 C, acute hypoxic respiratory failure requiring intubation and ventilator support. Blood cultures (BC) grew Enterococus faecalis and echocardiogram showed severe AI with aortic valve vegetations consistent with infective endocarditis. Renal function deteriorated, and the night before aortic valve surgery the patient required HD. HD was inadvertntly done using unprocessed city water. Post HD the patient had a fever to 38.8 C, calcium 13.9 mg/dl, magnesium 2.6 mg/dl, Hb 8.9 g/dl, haptoglobin 170 mg/dl, and normal indirect bilirubin. Repeat BC were negative. A "corrective" HD was performed the next morning immediaely before surgery using processed reverse-osmosis (RO) water for dialysate. The patient subsequently had uncomplicated AV replacement and has since been committed to long term HD. Discussion: Water quality and the composition of dialysate can influence exposure to potential chemical, bacterial, viral, & endotoxin contaminants. Bedside HD is conducted using dialysate prepared by portable RO systems designed to make ultrapure water. Patients receiving 3-4 hours of dialysis, using high flux membranes, are exposed to 108-144 L of dialysate wtih high potential for chemical and/or microbiological exposures. While the historical focus was on chemical contaminants, AAMI standards now define ultrapure water based on microbiolgical contaminants. Processed water should have < 200 CFU/ml bacteria, endotoxin concentration < 2 EU/ml, and < 2,000 CFU bacteria in dialysate. Limited city water analysis following this patient's eposure had concentrations of calcium at 68.78 mg/L (nl < 2.0) and magnesium at 21.28 mg/L (nl <4.0), both elevated, helped to explain her abnormal levels post dialysis. Microbiological contaminant seemed unlikley in absence of postive cultures. Absence of hemolysis or falling hemoglobin levels ruled against chloramine exposure. We conclude that this patient's accidental exposure to city water used to prepare dialysate did not have any negative impact on her successful recovery from enterococcal endocarditis but highlight the need to have a fail safe system to avoid connections to unprocessed water sources during bedside dialysis.