Epidemic aluminum intoxication in hemodialysis patients traced to use of an aluminum pump.

This study was designed to identify the source, risk factors, and clinical consequences of an outbreak of aluminum intoxication in hemodialysis patients using case-control and cohort studies. In 1991, a dialysis center in Pennsylvania [Dialysis Center A (DCA)] identified a number of patients with elevated serum aluminum levels. All patients receiving dialysis at DCA during January 1, 1987 to March 26, 1992 were involved in the study. A case-patient was defined as any patient with a serum aluminum level > or = 100 micrograms/liter after > or = 5 dialysis sessions at DCA. Fifty-nine case-patients were identified. Risk factors for elevated serum aluminum levels were receipt of bicarbonate- (rather than acetate-) based dialysate, higher number of sessions using bicarbonate dialysis, receipt of acid concentrate (used in bicarbonate dialysis) passed through one of two electric pumps, and a greater number of sessions using this concentrate. The electric pumps had an aluminum casing, casing cover, and impeller. Elevated levels of aluminum were found in acid concentrate after passing through a pump. Seizures and mental status changes requiring hospitalization were associated with aluminum exposure. We found that epidemic aluminum intoxication was caused by the use of an electric pump with aluminum housing to deliver acid concentrate used in bicarbonate dialysis. This outbreak demonstrates why it is essential to insure that all fluid pathways, storage tanks, central delivery systems, and pumps are compatible with low pH fluids before converting from acetate to bicarbonate dialysis.