Hygiene and sterilization
In a changing world where we travel more than ever and unintentionally exchange microbes in the interaction with other people, the demands for a well-functioning hygiene system couldn´t be higher. The infection pathways have become as short as the flight routes between the different corners of the earth. The main purpose of the hygiene system is to repetitively return non-disposable instrumentation to the next patient, in a manner that is safe for the environment, personnel and instrumentation. It is about breaking the pathway and preventing infections. One of the biggest global threats is antibiotic resistance. A well-functioning hygiene system is a way forward to reduce the use of antibiotics.
The instruments return from surgery/the treatment room. The tray is cleared of disposable items which are destroyed according to the manufacturer’s instruction.
Instrument and trays are cleaned and disinfected, ideally automatically in a washer disinfector. Modern disinfectors also feature active drying which is best practice; the instruments are dry when they are unloaded from the disinfector. Some tray systems allow cleaning with instruments in place in the tray. Follow the instrument or tray manufacturer´s instruction.
The clean and disinfected instrument is maintained according to the manufacturer’s instruction. Avoid overdosing oil and other lubricants as these will end up in the sterilizer resulting in shorter service intervals of the sterilizer.
Wrap the instruments in a material that fulfills norms and standards such as ISO 11607 and EN868. The packing material secure the sterility is kept over time. The expiry date of the package depends on material and sealing method.
The sterilizer is loaded according to the manufacturer’s instruction. In Quadro, heavy loads are placed in the lower part of the chamber and the light material in the upper. In this way the risk of moist load is reduced since heavy material generates more condensation than light material. The insert shall be used to avoid stacking trays / packing material. Small bags can be placed vertically to facilitate drying. Use perforated trays / loading systems which prevents condensate to be trapped causing moisture.
Process- and load release should be performed according to the clinic´s quality system by judging the result after the sterilization in terms of process and load:
- Process release:
- Has the process finished successfully without any alarms? With some sterilizers you need to evaluate the printout from the recorder / printer. Most B-cycle tabletop sterilizers, like Quadro, have a process evaluation system built in which means a green lamp or finish signal indicating the process is ok.
- Load release:
- When the sterilizer door is opened the goods should be dry. If there is some minor condensation on the packaging, judgement must be made as to wether it affects the sterile barriers.
- Is the packaging intact without damages? The smallest indication of damage and the load is not ok.
- If the clinic uses PCD (process challenge devices) Helix- or Bowie & Dick test, the color change shall be verified. Follow the instruction from the manufacturer of the test.
- If these parameters are ok, the load and process release is possible.
Quadro offer a documentation system where the sterilizer produces a number of pre-set labels that can be attached to the packaging, including batch number for traceability to the sterilization process. The process is then stored either on a USB-memory stick or via the local computer network. Alternative you can use a printer and document manually.
Process built-up Sterilizer
A sterilization process is intended to inactivate special heat-resistant bacteria, which are in spore form. All bacteria that are not in spore form will also be inactivated. The result is that the microbes cannot reproduce. Quadro uses saturated steam as sterilization medium, which is the most common in today in the tabletop sterilizer industry. For a successful process, it is important the instruments are clean and that all air, both in the chamber and in the load, is removed when the sterilizer enters the sterilization phase where the actual inactivation takes place.
A sterilizer is designed according to standards and directives. Quadro is built according to EN 13060. The description bellow describes the so-called the B-process from this standard, a process intended for all type of goods; solid, porous, hollow. It can be wrapped or unwrapped.
The sterilizer process is divided in four phases:
This is the phase where the sterilizer drives out the air from the chamber and load and heats up the load. This is done through several vacuum pulses, so called fractionated vacuum, where the air is replaced by steam.
2. Pressure increase – Equilibration
When the air is removed, the sterilizer increases the chamber pressure with saturated steam that penetrates the load. This is one of the more critical phases of the entire process and determines whether the sterilizer will cope with the sterilization of the load or not. When performing a Validation or Performance Qualification according to ISO EN 17665 a great deal of focus is put on this part. By measuring the temperature profile, you can determine if there is a full saturated steam penetration in the load.
It is in the sterilization phase the inactivation takes place. The sterilizer is regulating at a defined pressure for a certain period with saturated steam which gives a temperature in the intervals of 121-124°C or alternatively 134-137°C, depending on chosen program.
4. Post treatment
After the sterilization phase, the sterilizer drops the steam pressure and drives out all steam and condensate using a vacuum. It is important that the load is completely dry when the door is opened since this is the prerequisite for intact sterile barriers of the load. The vacuum will decrease the boiling point in the chamber and the hot remaining condensate will partly boil off and partly be evacuated out through the drain. Finally, the sterilizer equalizes the pressure through an air filter to atmospheric pressure. The process is finished, and the door can be opened.