JP2012187321A - Method for washing and disinfecting dialysate line in artificial dialyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a washing method of removing stains from the dialysate line in an artificial dialyzer to disinfect securely, while effectively preventing a hollow fiber membrane type dialysate filter located in the dialysate line from being deteriorated and reduced in function.SOLUTION: The dialysate line including the dialysate filter formed by bonding at least one side of a hollow fiber membrane bundle with a polyurethane base resin layer, is washed both with an aqueous hypochlorous acid-free alkaline solution and with an aqueous peracetic acid solution.

Description

  The present invention relates to a cleaning / disinfecting method for removing and sterilizing a dialysate line of a dialyzer used for artificial hemodialysis in a medical institution.

  In a medical institution equipped with an artificial dialysis facility, it is indispensable to keep the dialysis device and the dialysate line clean for patient safety. For this reason, it is necessary to carry out daily cleaning and disinfection after dialysis. Thus, dirt generated in the dialyzer and dialysate line after dialysis is mainly organic substances such as proteins and lipids and inorganic substances such as calcium carbonate, but it is not a simple adhesion form, and dirt components are laminated, The inorganic particles are entangled in the organic matrix, or the calcium and the organic matter form a composite, so that the bacteria that have entered the inside are easily propagated. Conventionally, two-stage cleaning using a sodium hypochlorite aqueous solution and an acetic acid aqueous solution has been widely employed for disinfecting and cleaning such dialyzers and dialysate lines. This uses the strong bactericidal and reactive properties of hypochlorous acid produced in the former aqueous solution to sterilize and disinfect organic stains, and convert calcium carbonate that cannot be removed with hypochlorous acid to acetic acid. It is dissolved and removed (Patent Document 1).

  There is also known a disinfectant (Patent Document 2) that contains a metal sequestering agent or surfactant in an aqueous sodium hypochlorite solution so that it can be disinfected by one-step cleaning. However, since there is a limit to the amount of the sequestering agent, periodic cleaning with an aqueous acid solution such as acetic acid has not been abolished. In addition, as other general disinfectants, aqueous solutions of isocyanurates such as sodium dichloroisocyanurate, electrolytic acidic water obtained by electrolysis of brine, aqueous solutions of peracetic acid and potassium monosulfate, acidic warmed aqueous solutions Etc. However, these disinfectants have the ability to remove calcium carbonate under acidic conditions, but the removability of organic substances is very poor, so that it is easy for residues to remain. It is a fatal defect that the sterilizing power is difficult to reach and that it leads to the growth of bacteria in and under the remaining dirt.

Japanese Patent Application Laid-Open No. 09-031494 Japanese Patent Laid-Open No. 07-233396

  In recent hemodialysis, in order to remove endotoxin (a cell membrane component of Gram-negative bacteria) that is a strong toxic substance for patients from the dialysate, dialysis is performed on the dialysate introduction part to the dialyzer (dialyzer) in the dialysate line. A liquid filter (ETRF: Endotoxin Retentive Filter) is often interposed. However, when a general hollow fiber membrane type filter in which the potting material is made of a polyurethane resin is used as the dialysate filter, when washing with the sodium hypochlorite aqueous solution is performed, with repeated washing, It has been found that the potting part gradually deteriorates and turns brown, and since the tendency of the water permeability to gradually increase is recognized, there is a concern that the filter function of the hollow fiber membrane is lowered.

  In view of the above-mentioned situation, the present invention is capable of reliably sterilizing the dialysis fluid line in an artificial dialysis apparatus by removing dirt, and the deterioration and functional deterioration of a hollow fiber membrane type dialysis fluid filter interposed in the dialysis fluid line. It aims at providing the washing | cleaning method which can suppress effectively.

  In order to achieve the above object, a method for washing and disinfecting a dialysate line in an artificial dialyzer according to claim 1 of the present invention is a dialysate filter in which at least one end of a hollow fiber membrane bundle is bound with a polyurethane resin layer. The dialysate line intervening is characterized by performing washing with a caustic aqueous solution containing no hypochlorous acid and washing with a peracetic acid aqueous solution.

  According to a second aspect of the present invention, in the method for washing and disinfecting a dialysate line in the artificial dialysis apparatus of the first aspect, the pH of the caustic aqueous solution is 9.0 to 13.0, and the peracetic acid concentration of the peracetic acid aqueous solution is 0.00. The composition is 001 to 0.1%.

  The invention of claim 3 is the dialysate line washing and disinfecting method in the artificial dialysis device of claim 1 or 2, wherein the hollow fiber membrane of the dialysate filter is made of any of polysulfone, polyester polymer alloy, and polyethersulfone. It is supposed to consist of

  According to the method for washing and disinfecting a dialysate line according to the first aspect of the invention, organic contaminants are reliably removed by the caustic aqueous solution, and inorganic contaminants such as precipitated calcium carbonate are also reliably removed by the peracetic acid aqueous solution. In addition, since degradation and functional deterioration of the hollow fiber membrane type dialysate filter interposed in the dialysate line can be effectively suppressed, the dialysate filter can be used continuously for a long time while ensuring high reliability. .

  According to the second aspect of the present invention, the caustic aqueous solution and the peracetic acid aqueous solution that are in a specific pH range and concentration are used, so that higher dirt removal and bactericidal properties can be secured.

  According to the invention of claim 3, the hollow fiber membrane of the dialysate filter is made of a specific resin component, and the function of the conventional washing with a sodium hypochlorite aqueous solution is concerned even though the filter function may be lowered. Can be reliably prevented.

  The application target of the cleaning and disinfecting method according to the present invention is a dialysate line in which a dialysate filter in which at least one end of a hollow fiber membrane bundle is bound with a polyurethane resin layer is interposed. Such a hollow fiber membrane filter is known to have a particularly high function as a dialysate filter. However, in the conventional washing with a general sodium hypochlorite aqueous solution, the potting portion, that is, the polyurethane resin layer gradually deteriorates. Since the color changes to brown, there is a concern that amino groups (—NH) and cyano groups (—CN) in the polyurethane are decomposed and chlorinated to produce chloramine and cyan chloride. Moreover, the tendency for water permeability to rise gradually is recognized, and there is a concern that the filterability may decrease due to the expansion of pores.

  In the cleaning and disinfecting method of the present invention, such a dialysate line is cleaned with a caustic aqueous solution containing no hypochlorous acid and with a peracetic acid aqueous solution, thereby completely removing and reliably removing dirt. It is possible to maintain a clean dialysis environment by effective sterilization, and to effectively suppress the deterioration of the potting part in the above-mentioned hollow fiber membrane type dialysate filter, and to reliably prevent an increase in water permeability. High endotoxin removability due to the excellent filter function can be stably exhibited over a long period of time.

  First, the aqueous caustic solution described above has an action to remove organic soils such as proteins and lipids. By using this to wash the dialysate line after the completion of dialysis, the attached soil is composed of a composition. And even if it is morphologically complicated, the organic part is removed so that it can be effectively peeled off, and it can be sterilized while excluding the place where bacteria grow, so it was wrapped in organic matter. Exposes inorganic dirt such as calcium carbonate to facilitate release from the vessel wall. Moreover, since the aqueous caustic solution does not contain hypochlorous acid, the potting portion made of polyurethane resin in the hollow fiber membrane type dialysate filter is not deteriorated, and the water permeability of the hollow fiber membrane is not increased. Is known.

  Such a caustic aqueous solution is not particularly limited, but those in the range of pH 9 to 13 are suitable. If this pH is too low, the soil removing action and sterilizing action will be insufficient, and conversely the pH If it is too high, there is a problem in that deterioration of some materials such as silicon rubber is accelerated.

  The caustic aqueous solution can be set at a low concentration and a high pH, but the pH buffering property is weak, and the pH is lowered by mixing and contacting with various types of dirt. However, this difficulty can be improved by adding a pH buffering agent. Examples of such pH buffering agents include organic acid salts, organic phosphonates, phosphates, borates, alkanolamine salts, bicarbonates, etc., and these may be used in combination of two or more.

  In the conventional cleaning method mainly using sodium hypochlorite, there is a concern that the stainless steel used in a part of the dialysis machine is highly corrosive. However, this cleaning method uses sodium hypochlorite. In addition, since the corrosiveness of the aqueous caustic alkali solution having a pH of 9 to 13 to stainless steel is very low, there is an advantage that the rust prevention management of the dialysate line and the periodic rust prevention work can be reduced.

  On the other hand, the aqueous solution of peracetic acid has an excellent dissolving action on inorganic substances such as calcium carbonate. By washing the dialysate line using this, the soil of inorganic substances that cannot be sufficiently removed by the aqueous caustic solution solution is used. Is dissolved and removed, and has a strong sterilizing power, and therefore contributes to the reliable sterilization of the dialysate line in combination with the organic soil removal effect by the caustic aqueous solution. In the present invention, a peracetic acid aqueous solution is used because a sufficient sterilizing and disinfecting effect cannot be obtained with a caustic aqueous solution.

  Such a peracetic acid aqueous solution is not particularly limited, but those having a peracetic acid concentration in the range of 0.001 to 0.1% are suitable. If this concentration is too low, the soil removing action and the sterilizing and disinfecting action are suitable. However, if the concentration is too high, rubber parts such as O-rings swell and deteriorate.

  The peracetic acid aqueous solution exhibits an excellent sterilizing and disinfecting action at a concentration of 0.001% or more and can dissolve calcium carbonate according to the amount of acetic acid contained. As such an aqueous solution of peracetic acid, a solution containing 0.4 to 8% peracetic acid, less than 6 to 22% hydrogen peroxide, and 4 to 40% acetic acid is commercially available.

  A general dialysate line washing order is a final process using a chemical solution having a sterilizing effect. This is thought to be due to fear that bacteria will propagate in the line at night after washing. The conventional washing sequence with sodium hypochlorite and acetic acid is, after continuous washing with acetic acid, washing with sodium hypochlorite. On the other hand, organic contaminants such as proteins may be denatured under acidic conditions and become difficult to remove. In this regard, the combination of the present cleaning agents is expected to have a sterilizing and disinfecting effect on the acid side, so that cleaning with a peracetic acid aqueous solution is performed next to cleaning with a caustic aqueous solution. The point that organic substances can be removed before acid cleaning leads to an improvement in cleaning performance, which is considered to be advantageous in increasing the efficiency of subsequent cleaning and disinfection.

  The washing of the dialysate line according to the present invention is preferably performed in two steps with the caustic aqueous solution and the peracetic acid aqueous solution at the end of dialysis. However, depending on the degree and tendency of dirt, the type of washing liquid used, etc. It is not limited to two-stage washing at the end of dialysis. That is, when there is always a tendency for organic matter to be less contaminated, cleaning with a peracetic acid aqueous solution is performed every day, and cleaning with a caustic aqueous solution is also used every other day.

  In a medical institution having an artificial dialysis facility, RO (reverse osmosis) water is supplied to the dialysis machine and dialysate line where the artificial dialysis is performed once a day after the completion of dialysis for 15 minutes, and then the following alkaline detergent The test program was carried out for 3 months, in which water was washed for 30 minutes, washed with RO water for 90 minutes, then the following acidic detergent was fed for 30 minutes, and then washed with RO water for 90 minutes. After this test, soil removal and sterilization were evaluated by the methods described later, and changes in the hollow fiber membrane type dialysate filter interposed in the dialysate line were examined. The results are shown in Table 1 below. In addition, as a hollow fiber membrane type dialysate filter, a new product of trade name TET1.0 (potting part: polyurethane resin, hollow fiber membrane: polysulfone) manufactured by Toray Industries, Inc. is used and a patient monitoring device manufactured by Toray Industries, Inc. is used. The trade name TR-3000M was used. Further, the supply amounts of the alkaline detergent, acidic detergent, and RO water were all set to 500 ml / min.

<Alkaline cleaning agent>
[A1] 0.04% NaOH aqueous solution, pH 12
[A2] 0.004% NaOH aqueous solution, pH 11
[A3] 0.0004% NaOH aqueous solution, pH 10
[A4] 0.00004% NaOH aqueous solution, pH 9
[A5] 0.4% NaOH aqueous solution, pH 13
[A6] 0.1% NaClO aqueous solution, pH 10.5.
<Acid cleaning agent>
[B1] Peracetic acid aqueous solution (containing 0.02% peracetic acid and 0.2% acetic acid), pH 3.1
[B2] 0.2% aqueous acetic acid solution, pH 3.1

<Removability of dirt>
[Protein] For the silicone tube in the drainage line after dialyzation, the degree of staining with the amide black 10B test solution was examined, 0 for no staining, 5 for unwashed staining immediately after dialysis, and 0-6 Rated by stage.
[CaCO ₃ ] For the drain tube after the dialyzer, the coloration of calcium was examined by the orthophthalein complexone (OCPC) method, ○ indicating no coloration, △ light coloration, △ dark coloration. It evaluated in three steps made into x.

  <Sterilization> 50 ml of dialysate collected immediately before the hollow fiber membrane type dialysate filter installed in the patient monitoring device is filtered with a membrane filter, and this filter is placed on the R2A medium at 25 ° C. After culturing for 7 days, the grown colonies were counted and evaluated as CFU (colony forming unit).

<Change of dialysate filter>
[Discoloration of potting part] The degree of discoloration was visually observed and evaluated in three stages, with ○ indicating that the color did not change and a new one, Δ indicating a light brown color change, and × indicating a dark brown color change.
[Water permeability] The water permeability (ml / h mmHg) of the dialysate filter was measured. The permeability of the new product was 4.0 ml / h mmHg.

  As is clear from the results in the above table, the cleaning and disinfecting method according to the present invention (Test Nos. 1 to 5) provides excellent dirt removal and sterilization, and causes discoloration of the potting portion of the dialysate filter. There was also no increase in water permeability in the filter. Therefore, according to the cleaning and disinfecting method of the present invention, it can be seen that the dialysate filter can be used continuously for a long time while ensuring high reliability. In addition, it is estimated that the water permeability decreased from the time of a new article that fouling with time is caused by silicon fine particles or iron contained in dialysate or RO water, and is usually assumed from the filter function. It is a phenomenon. It can be seen that the concentration of the caustic aqueous solution is preferably 0.004% or more for completely removing protein stains.

  On the other hand, the cleaning and disinfecting method using sodium hypochlorite aqueous solution as an alkaline cleaning agent (Test Nos. 7 and 8) has good stain removal and disinfection, but the potting part of the dialysate filter turns dark brown. In addition, the water permeability of the filter is also increased. The cause of the increase in water permeability is not only the deterioration of the potting part, but also the pore diameter expansion due to the deterioration or alteration of the hollow fiber membrane. Therefore, in the conventional two-step cleaning with a general sodium hypochlorite aqueous solution and an acidic cleaning liquid, there is a concern that the filter is deteriorated and the function is deteriorated at an early stage and the original endotoxin removing function is lost.

Claims (3)

  For a dialysate line intervening with a dialysate filter in which at least one end of the hollow fiber membrane bundle is bound with a polyurethane resin layer, washing with a caustic aqueous solution containing no hypochlorous acid, washing with a peracetic acid aqueous solution, A method for cleaning and disinfecting a dialysate line in an artificial dialysis machine.   The pH of the aqueous caustic solution is 9.0 to 13.0, and the concentration of acetic acid in the aqueous solution of peracetic acid is 0.001 to 0.1%. Method.   The method for washing and disinfecting a dialysate line in an artificial dialysis machine according to claim 1 or 2, wherein the hollow fiber membrane of the filter for artificial dialysis is made of any material of polysulfone, polyester-based polymer alloy, and polyethersulfone.