Normas Calidad De Agua

Nephrol Dial Transplant (2002) 17 [Suppl 7]: 45–62

Recommendations of the European Pharmacopoeia. The use of ultrapure water is however strongly recommended for conventional and high-flux dialysis modalities. (Evidence level: C )

Commentary on Guideline IV.1
According to the degree of desired water purity, the complexity and the cost of the water treatment system may differ significantly.Two different grades of water purity may be used for haemodialysis: (i) pure water and (ii) ultrapure water. Pure water is the basic form of treated water that is suitable for conventional haemodialysis modalities [9]. Water treatment relies on different technical options that are detailed in the Appendix [10]. Briefly, purified water is easily obtained from a purification system consisting ofpre-treatment (softener, activated carbon, downsizing microfilters), a reverse osmosis (RO) unit [11], and deionizer [12,13] implemented in series to prevent mainly aluminum intoxication [14–16] but also the accumulation of various water pollutants [17–20]. Microbiological contamination of the delivered water should comply with the recommendations of the European Pharmacopoeia (bacterial count -100CFUuml and endotoxin content -0.25 EUuml). Maximum levels of the different water purity grades are presented in Table 1. Maximum water contaminant levels and methods of analysis recommended by the European Pharmacopoeia and compared with those of the AAMI are presented in Table 2. Ultrapure water may be used alternatively on a regular basis with all kinds of haemodialysis modalities. Ultrapure wateris highly desirable with high-flux haemodialysis modalities and represents a basic prerequisite for dialysis modalities using on-line production of substitution fluid (on-line haemofiltration HF or haemodiafiltration HDF) [21]. Several technical options and arrangements may be used to reach this goal [22]. They are presented in the Appendix. The most common water treatment system option is based onpre-treatment and a double-stage RO module in series. Microbiological contamination in this case complies with more stringent standards (Table 1).

IV.1 Water treatment system
From the early days of dialysis it is known that water used for haemodialysis must be purified in order to prevent severe clinical side effects due to contamination of the water [3–8]. In brief, this means that all watercontaminants (particles, dissolved substances such as ions, trace elements, organic substances, nitrogen compounds, and microorganisms) should be removed prior to entering the dialysis machine.

Guideline IV.1
A. Contemporary haemodialysis requires the use of pure water complying at a minimum with the
#

2002 European Renal Association–European Dialysis and Transplant Association

46Table 1. Maximum levels of the different water purity grades Maximum levels AAMI Water European Pharmacopoeia Regular water Microbial contamination (CFUuml) Bacterial endotoxins (lUuml) 200 -2 -100 -0.25

SECTION IV. Dialysis fluid purity

Ultrapure water -0.1 -0.03

Sterile water -0.000001 -0.03

Table 2. Comparison of maximum water contaminant levels and methods of analysis recommended bythe European Pharmacopoeia and the AAMI Contaminant Methods of analysis Maximum concentration (mgul) AAMI European Pharmacopoeia 0.0100 0.0060 0.0050 0.1000 0.0004 0.0010 2 (0.05 0.1000 0.0140 0.1000 0.0200 0.2000 0.5000 0.0050 2 (0.08 0.0010 2.0000 2 (0.08 0.0900 0.0050 50 (2.2 100 0.0020 0.1000

Aluminum Antimony Arsenic Barium Beryllium Cadmium Calcium Chloramines Chromium Copper CyanideFluoride Free chlorine Lead Magnesium Mercury Nitrate Potassium Selenium Silver Sodium Sulfate Thallium Zinc

Atomic absorption spectrometry Atomic absorption spectrometry Atomic absorption spectrometry Atomic absorption spectrometry Atomic absorption spectrometry Atomic absorption spectrometry Atomic absorption spectrometry Colorimetry Atomic absorption spectrometry Atomic absorption spectrometry...