DE102014213656A1 - Method for cleaning surgical instruments - Google Patents

Abstract

The invention relates to a method for automated cleaning of medical instruments, comprising the steps of: a) carrying out a purification with a mildly alkaline, enzymatic cleaning agent at a pH of 9 to 11; b) adding a peroxide component to the cleaning solution of step a) and further cleaning at a temperature at least 5 K above the temperature in step a); c) rinse.

Description

The present invention relates to a method for automated cleaning of medical and / or surgical instruments and / or apparatus.

Surgical instruments as well as other medical devices are usually cleaned in the hospital using alkaline detergents and then disinfected chemically or thermally. Such alkaline agents can be aggressive to sensitive surfaces. Surgical instruments contaminated with blood are often stored in a dry state immediately after use until they have been treated, so that blood residues can dry to stubborn soiling. Alternatively, they are placed in a disinfectant solution and remain there initially, until they are cleared for cleaning in the dishwasher. The blood is coagulated by the disinfectant and the protein components contained in the blood denatured by the disinfectant. Particularly stubborn blood residues are often only to be removed by alkaline-active chlorine-containing cleaning agents. The oxidizing Aktivchlorkomponente causes the decomposition of the denatured protein components. Also other components of e.g. Skin disinfectants such as iodine can form residues that are difficult to remove.

Alkaline-active chlorine-containing cleaners have the disadvantages that they contain hazardous substances requiring labeling, that special precautions for the protection of the operating personnel are required in their handling and that they represent an undesirable environmental impact in the wastewater. They are therefore used only little today.

Out EP 1 327 674 A1 It is known to use mild alkaline, enzymatic cleaners for the stated purpose. EP 1 454 637 A1 discloses a two-step process for the cleaning of medical instruments, wherein alkaline is purified in the first stage and in the second stage fresh alkaline cleaner is used together with a peroxide.

The present invention is based on the object to provide a method of the type mentioned above, which is simple and easy to use, works gently and provides good cleaning performance even with difficult to remove blood residues.

• a) Durchführen einer Reinigung mit einem mildalkalischen, enzymatischen Reinigungsmittel bei einem pH-Wert von 9 bis 11;
• b) Zufügen einer Peroxidkomponente zu der Reinigungslösung aus Schritt a) und weiteres Reinigen bei einer Temperatur, die wenigstens 5 K oberhalb der Temperatur in Schritt a) liegt;
• c) Spülen.

This object is achieved by an initially mentioned method with the following steps:

• a) performing a purification with a mildly alkaline, enzymatic detergent at a pH of 9 to 11;
• b) adding a peroxide component to the cleaning solution of step a) and further cleaning at a temperature at least 5 K above the temperature in step a);
• c) rinse.

First, some terms used in the invention are explained.

The invention relates to mechanical cleaning. Machine means that the operation is carried out by a suitable machine, preferably a washer-disinfector (RDG). The term cleaning is to be understood in the context of the invention comprehensively in the sense of cleaning and / or disinfecting and in particular comprises the depletion of pathogens.

The term medical instruments comprehensively refers to all medical and / or surgical instruments and / or apparatus or parts thereof that are used in the medical or hospital environment, including appropriate items used by nursing staff in the context of patient care.

The method according to the invention comprises the three method steps defined in claim 1, which are carried out in the order stated there without intervening steps. Upstream and / or downstream steps are not excluded, as will be explained below.

First, a cleaning with a mild alkaline, enzymatic detergent is performed. This is used in aqueous solution, this aqueous solution has a pH of 9-11. Further preferred ranges of the pH are 9-10.5 and 9.5-10.5, respectively.

By means of this mildly alkaline, enzymatic cleaning, the invention permits, on the one hand, an effective removal, in particular of (possibly also coagulated) blood residues, on the other hand, this mildly alkaline cleaning is less aggressive towards sensitive materials such as, for example, plastics or aluminum.

It is an essential aspect of the invention that, following this first cleaning step, a peroxide component is added to the cleaning solution already used and then further cleaning takes place at a temperature which is at least 5 K above the temperature in step a).

In the prior art ( EP 1 454 637 A1 ), however, an alkaline cleaning is first carried out and then changed the soiled cleaning solution. It is expressly emphasized that the change of the cleaning solution before the addition of the peroxide is essential in order to avoid a disintegration and thus an inactivation of the peroxide by suspended particles of dirt.

By contrast, the present invention has recognized that a peroxide in the second purification step (step b)) can easily develop its cleaning and disinfecting action, even though it is metered into a cleaning solution that has already been used and is thus suspended in the presence of dirt particles. The present invention thus avoids the change in the cleaning solution between the two steps considered essential in the prior art and thus reduces the amount of potentially contaminated wastewater and the time required to carry out the cleaning and / or disinfection.

The invention further requires the use of the peroxide at a higher temperature than in the first cleaning step. The heating to this higher temperature can according to the invention be carried out before, during or after the addition of the peroxide. The slightly higher temperature increases the rate of decomposition of the peroxide and thus the formation of the active oxygen. In general, a higher temperature leads to a reduction of the enzyme activity, but this can readily be accepted, since the enzymes have already unfolded their cleaning action in the first step (step a)).

The addition of the peroxide component and the subsequent reactions usually further reduce the pH of the cleaning solution, this pH was in step a) initially between 9 and 11. It can in the course of cleaning in step b), for example, by 0.5 -2, preferably 0.5-1.5, typically drop about 1.

The invention thus uses in step a) a relatively low alkaline cleaning solution anyway, this alkalinity is further reduced in step b). This makes it possible to carry out only rinsing (preferably with water) after step b) and to completely dispense with the neutralization with an acid neutralizing agent required in the prior art. This waiver of neutralization is another important advantage of the process of the invention.

The purification in step a) may preferably be carried out at a temperature of 30 to 50 ° C, more preferably 35 to 45 ° C. In this temperature ranges, conventional enzymatic, mildly alkaline cleaners can in particular exert the cleaning action of the enzymes and are little or hardly aggressive to sensitive materials.

A preferred duration of this first purification step a) may according to the invention be 2-10 min, more preferably 3-8 min, more preferably 4-6 min. A typical cleaning time is 5 min.

Suitable enzymatic cleaners for step a) are, for example, under the name ^® neodisher MediClean forte from the Fa. Dr. Weigert available and disclosed in EP 1 327 674 A1 , The disclosure of this document with regard to the composition of suitable cleaners is made by reference to the subject of the present application. In this respect, preference may be given to enzymatic cleaners containing at least one alkanolamine and at least one aminopolycarboxylic acid and / or salts thereof, as disclosed in said EP-document

The temperature difference between the purification processes in step a) and b) is preferably 5 to 20 K, more preferably 10 to 20 K or 10 to 15 K. It is further preferred that the purification in step b) at a temperature of 35 to 65 ° C, preferably 40 to 60 ° C, more preferably 50 to 60 ° C.

Particularly preferred temperature ranges for step a) are, for example, 35-40 ° C., for step b) 55-60 ° C.

A preferred duration of this second purification step b) may according to the invention be 2-10 min, more preferably 3-8 min, more preferably 4-6 min. A typical cleaning time is 5 min.

The peroxide component added in step b) may preferably contain hydrogen peroxide, if appropriate also (less preferably) peracetic acid. It may be, for example, a concentrate having a hydrogen peroxide content of about 30% that in a concentration of, for example, 0.1 to 1 vol .-%, preferably 0.3 to 0.8 vol .-% in the cleaning solution Step a) can be metered. Other suitable per compounds may also be used.

It is inventively preferred if prior to step a) additionally a conventional pre-rinse takes place. This can be done, for example, with cold or possibly warm water. Coarse dirt can be removed in this way.

Following the rinsing in step c), a thermal disinfection preferably takes place. This can, as in principle from the prior art known, for example, with water at 93 ° C for a period of, for example, 5-10, preferably about 5 min.

An embodiment of the invention will be explained below together with a comparative example. In the drawing show:

1 : Results of the cleaning process according to the invention;

2 : Results of the comparative experiment.

The following commercially available cleaning agents of the company. Weigert were used:
neodisher ^® FA (alkaline detergent)
neodisher ^® OXIVARIO (hydrogen peroxide-based oxidation component)
neodisher ^® ORTHOVARIO (pH-neutral surfactant component)
neodisher ^® N (acid neutralizer based on phosphoric acid)
neodisher ^® MediClean forte (Enzymatic, mild alkaline cleaner according to EP 1 327 674 A1 )

Stainless steel plates were used to carry out the cleaning tests. On a slightly roughened surface of 5 × 10 cm in each case 400 .mu.l soiling (heparinized, reactivated sheep blood, Fa. ACILA) was applied and dried at room temperature (23 ° C) for 3.5 h.

The prepared plates were placed in an instrument dishwasher (Miele Professional PROFITRONIC PG 8535). In two separate experiments, the programs described below were carried out according to the comparative example and example. It was used in each case DI water.

example

• – Vorspülen (Kaltwasser 10°C, 2 min, Verwerfen des Vorspülwassers)
• – Reinigen 1 (40°C, 0,45 Gew.-% neodisher^® MediClean Forte, 5 min, kein Verwerfen der Lösung nach Abschluss)
• – Reinigen 2 (55°C, zusätzlich 0,3 Gew.-% neodisher^® OXIVARIO zudosiert, 5 min, Verwerfen der Lösung nach Abschluss)
• – Spülen (Kaltwasser 10°C, 1 min)

The program sequence according to the invention had the following steps:

• - Pre-rinse (cold water 10 ° C, 2 min, rejection of pre-rinse water)
• - Clean 1 (40 ° C, 0.45 wt .-% neodisher ^® MediClean Forte, 5 min, no warping of the solution after completion)
• - Clean 2 (55 ° C, in addition 0.3 wt .-% neodisher ^® OXIVARIO metered, 5 min, discarding the solution after completion)
• - Rinse (cold water 10 ° C, 1 min)

The rinsed platelets were removed, dried at room temperature and the cleaning performance visually checked. To detect blood residues, they were stained with amido black solution. The thus treated platelets are in 1 shown. It can be seen that according to the invention a complete removal of the blood residues has been achieved.

Comparative example

• – Vorspülen (Kaltwasser 10°C, 2 min, Verwerfen des Vorspülwassers)
• – Reinigen 1 (55°C, 0,2 Gew.-% neodisher^® ORTHOVARIO, 5 min, Verwerfen der Lösung nach Abschluss)
• – Reinigen 2 (55°C, 0,2 Gew.-% neodisher^® ORTHOVARIO, 0,1 Gew.-% neodisher^® FA, 0,3 Gew.-% neodisher^® OXIVARIO, 5 min, Verwerfen der Lösung nach Abschluss)
• – Neutralisation (10°C, 0,1 Gew.-% neodisher^® N, 1 min)
• – Spülen (Kaltwasser 10°C, 1 min)

The program sequence of the comparative example had the following steps:

• - Pre-rinse (cold water 10 ° C, 2 min, rejection of pre-rinse water)
• - Clean 1 (55 ° C, 0.2 wt .-% neodisher ^® ORTHOVARIO, 5 min, discarding the solution after completion)
• - Clean 2 (55 ° C, 0.2 wt .-% neodisher ^® ORTHOVARIO, 0.1 wt .-% neodisher ^® FA, 0.3 wt .-% neodisher ^® OXIVARIO, 5 min, discarding the solution after completion)
• - Neutralization (10 ° C, 0.1 wt .-% neodisher ^® N, 1 min)
• - Rinse (cold water 10 ° C, 1 min)

The rinsed platelets were removed, dried at room temperature and the cleaning performance visually checked. To detect blood residues, they were stained with amido black solution. The thus treated platelets are in 2 shown. It can be seen that, according to the comparative example, a poorer cleaning performance was achieved than according to the invention.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1327674 A1 [0004, 0021, 0031]
• EP 1454637 A1 [0004, 0014]

Claims (12)

Method for mechanically cleaning medical instruments, comprising the steps of: a) performing a purification with a mildly alkaline, enzymatic detergent at a pH of 9 to 11; b) adding a peroxide component to the cleaning solution of step a) and further cleaning at a temperature at least 5 K above the temperature in step a); c) rinse. A method according to claim 1, characterized in that the cleaning in step a) at a temperature of 30 to 50 ° C, preferably 35 to 45 ° C. A method according to claim 1 or 2, characterized in that the cleaning in step a) over a period of 2 to 10 minutes, preferably 3 to 8 minutes, more preferably 4 to 6 minutes. Method according to one of claims 1 to 3, characterized in that the cleaning in step a) takes place at a pH of 9 to 10.5. Method according to one of claims 1 to 4, characterized in that the purification in step a) is carried out with an enzymatic cleaner containing at least one alkanolamine and at least one aminopolycarboxylic acid and / or salts thereof. Method according to one of claims 1 to 5, characterized in that the purification in step b) takes place at a temperature which is 5 to 20 K, preferably 10 to 20 K higher than in step a). Method according to one of claims 1 to 6, characterized in that the cleaning in step b) at a temperature of 35 to 65 ° C, preferably 40 to 60 ° C, more preferably 50 to 60 ° C. Method according to one of claims 1 to 7, characterized in that the cleaning in step b) over a period of 2 to 10 minutes, preferably 3 to 8 minutes, more preferably 4 to 6 minutes. Method according to one of claims 1 to 8, characterized in that the peroxide component added in step b) contains hydrogen peroxide and / or peracetic acid. A method according to any one of claims 1 to 9, characterized in that prior to step a) additionally comprises a pre-rinsing takes place. Method according to one of claims 1 to 10, characterized in that after step c) additionally takes place a thermal disinfection. Method according to one of claims 1 to 11, characterized in that it has no neutralization step.

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