title: Methaemoglobinaemia and haemolysis associated with hydrogen peroxide in a paediatric haemodialysis centre: a warning note.
abstract: BACKGROUND
  Haemodialysis exposes patients to contaminants in the dialysate. The AAMI standards deal only with two disinfectants, chlorine and chloramine. We report an event of methaemoglobinaemia and haemolysis related to an unsuspected disinfection agent.
  
  
  METHODS
  Nine children aged 3-17 years undergoing dialysis after reconstruction of our paediatric dialysis unit developed methaemoglobinaemia of 3.1-11%, with a mean reduction in haemoglobin levels of 11.9 +/- 5.9% (P < 0.001). Air bubbles were noted in the bloodlines. The water treatment system (WTS) of the dialysis unit is disinfected when necessary by adding concentrated hydrogen peroxide (HP) to the storage tank and circulating it through the re-circulation loop with draining and subsequent flushings. Total chlorine analysis of the water is performed by DPD-iodide colorimetric method.
  
  
  RESULTS
  Dialysis water testing yielded a high chloramine concentration in the storage tank and points- of-use stations (3.08 and 2.06 p.p.m., respectively). However, this finding was not true for the tap water, and it also failed to explain the air bubbles in the dialysis tubing. The concentration of free chlorine was within the recommended range. Further investigation revealed that the WTS was disinfected by the service company during remodelling of the unit, without notification of the hospital staff. Since the DPD-iodide test is not specific, and in effect detects not only total chlorine, but all oxidants capable of oxidizing iodide, we assumed the culprit was residual HP that was inadequately flushed from the water system.
  
  
  CONCLUSIONS
  HP used for disinfection of the WTS can pose a serious dialysis risk if not flushed out properly. Total chlorine analysis should be performed before every dialysis session, and positive results should prompt further work-up for other oxidants. The clinical staff must always be involved in decisions regarding any intervention in the dialysis water system.
authors.affiliation: Nephrology Clinic and Dialysis Unit, Schneider Children's Medical Center of Israel, Petah Tikva, Israel. joyces@clalit.org.il
authors.forename: Miriam
authors.initials: M
authors.lastname: Davidovits
authors.forename: Ayala
authors.initials: A
authors.lastname: Barak
authors.forename: Roxana
authors.initials: R
authors.lastname: Cleper
authors.forename: Irit
authors.initials: I
authors.lastname: Krause
authors.forename: Zahava
authors.initials: Z
authors.lastname: Gamzo
authors.forename: Bella
authors.initials: B
authors.lastname: Eisenstein
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002700:Chloramines / Q000032:analysis; D002713:Chlorine / Q000032:analysis; D004202:Disinfectants / Q000009:adverse effects*; D015312:Hemodialysis Solutions / Q000009:adverse effects / Q000737:chemistry*; D006461:Hemolysis / Q000187:drug effects*; D006801:Humans; D006861:Hydrogen Peroxide / Q000009:adverse effects*; D008708:Methemoglobinemia / Q000139:chemically induced*; D006435:Renal Dialysis; D018508:Water Purification / Q000379:methods
chemical_list: D002700:Chloramines; D004202:Disinfectants; D015312:Hemodialysis Solutions; D002713:Chlorine; D006861:Hydrogen Peroxide; C030816:chloramine