Hemodialysis is a method for removing uremic toxins and water directly from the blood into a dialysis fluid through an artificial semipermeable membrane called a dialyzer.
The ability of the dialyzer to remove uremic toxins has steadily improved, but the likelihood has also increased that bioactive substances, such as bacterial endotoxin (ET) fragments, can be transferred from the dialysis fluid into the patient’s blood through the phenomena of back-diffusion and back-filtration in the dialyzer.
Endotoxins form part of the cell walls of some Gram-negative bacteria. Some endotoxins are shed while bacteria are alive—and when they die, large amounts are released. Since endotoxins are not alive, we cannot kill them. Endotoxemia (endotoxins in the blood) can cause inflammation. Endotoxins can pass into the patient’s blood through an intact dialyzer membrane. If this happens, a pyrogenic reaction may occur, and the patient may have: Chills and/or fever, low blood pressure, nausea and vomiting, muscle aches.
Therefore, further efforts to improve the quality of water are required. but achieving and maintaining these standard values would seem difficult without installing an ET-retentive filter (ETRF).
To protect HD patients from exposure to chemical and microbiologic contaminants dialysis units must follow the manufacturer’s recommendations in relation to management of haemodialysis machines.
Manufacturers producing dialysis machines each recommend a different procedure for decontamination, but they concentrate only on bacterial kill. It is recommended that efficacy of decontamination procedure should additionally take into account level of biofilm and endotoxin removal.
Ultrapure dialysis fluid is produced by filtering standard dialysis fluid through endotoxin retentive filter immediately before the dialysis fluid enters the dialyzer.
Contemporary dialysis machines are designed so that bacterial and endotoxin retentive filters can be installed as an integral part of the dialysis fluid pathway.
This design enables the filters to be sanitized whenever the dialysis machines are disinfected.
Because dialysis membranes vary in their capacity to remove microbiologic contaminants, only filters that have been validated by the manufacturer to remove bacteria and endotoxin for a given period of time or number of dialysis treatments (even with repeated disinfection) should be used for the final filtration step.
Endotoxin Retentive Filter
| Endotoxin retentive filter | CF-609N or “cut filter” | Diasafe Plus | U9000 ultrafilter | EF-01D
EF-02D
|
| Manufacturer | Nipro | Fresenius | Baxter | NIKKISO
|
| Membrane | Polyethersulfone (PES) | Polysulfone | PAES/PVP-Polyaryl Ether Sulfone-Polyvinylpyrrolidone | PEPA(Polyester-Polymer Alloy) |
| Compatible with | SurdialTM X and SurdialTM 55Plus | Fresenius HD system equipped with the Diasafe Plus holder | Baxter HD system equipped with the U9000 holder | EF-01D
DBB-03, DBB-05 (until SN 603132-04) EF-02D DBB-05 (from SN 603133-01), DBB-06, DBB-07, DBB-EXA |
| Operating Time | 200 treatments | Max. 12 weeks or 100 treatments | On the AK98 V2, V3 and Artis dialysis system: after 3 months of usage or 150 disinfection cycles, whichever comes first.On the AK 96 and AK 98 V1 dialysis system: after 2 months of usage or 100 disinfection cycles, whichever comes firstMaximum 12 disinfections with sodium hypochlorite over the lifetime of the U9000Maximum 8 disinfections with sodium carbonate over the lifetime of the U9000 | Max 750 hours |
| Disinfection | Citrix-LA contains Citric acid, Malic acid and Lactic acid
|
Puristeril 340 or Puristeril Plus (Peracetic Acid)
Diasteril (Hydroxyacetic Acid) or Citrosteril (Citric Acid) Sporotal 100 (Sodium Hypochlorite) – Max. 11 times
|
Peracetic acid (≤0.1%)
Sodium carbonate (≤0.5%) Sodium hypochlorite (≤0.5%) Citric acid (≤2.0%) The U9000 ultrafilter is compatible with heat disinfection
|
Citric acid, Peracetic acid, Sodium hypochlorite
|
*This data is as per manufacturer. Given for basic understanding.
Source:TEXTBOOK OF DIALYSIS THERAPY and data from manufacturers of Endotoxin retentive filter
Article Courtesy – Dr. Jigar Shrimali
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