The sterilization of instruments and medical equipment is one of the basic gestures of preserving health, just like hygiene. Sterilizing the equipment used makes it possible to protect against cross-contamination between patients and medical personnel, and between the patients themselves, by destroying the potentially pathogenic microorganisms present.

The Poupinel is one of the ovens intended for the sterilization of medical instruments.

The Poupinel, also called the Pasteur oven, was invented in 1885 by the French surgeon Gaston Poupinel, a student of Louis Pasteur. It is a sterilization oven that uses dry heat to destroy germs.

Composition

The Poupinel is presented as a waterproof double-walled metal box, closed by a hermetic door. The hot air in the oven is distributed evenly thanks to a fan that runs constantly. A stainless steel tray accommodates the instruments to be sterilized. On the front, a control panel for programming and controlling the oven includes:

• a thermostat to program the temperature (0 to 200 ° C);
• a timer (0 to 120 minutes);
• a thermometer making it possible to follow the evolution of the temperature in the oven;
• security lights.

The Poupinel is a dry heat sterilizer intended for the sterilization of instruments and syringes. Sterilization is carried out by hot, dry air circulating inside the sealed enclosure, without increasing pressure.

Dry heat sterilization is used to sterilize surgical or care instruments: scalpels, forceps, clamps, needles, probes, syringe bodies, etc.

Useful temperatures

Depending on the type of instruments to be sterilized, the temperature level and the heating time will not be the same:

• 30 minutes at 180 ° C for most instruments;
• 20 minutes at 120 ° C for scalpels and fragile instruments;
• 45 to 60 minutes at 160 ° C for syringes.

The purpose of high temperatures is to destroy microorganisms. They act by destroying the structural proteins of germs by coagulation and / or oxidation.

The efficiency of dry heat

The dry heat of Poupinel destroys bacteria, spores, viruses, fungi and parasites. But prions resist this mode of sterilization. This is why the use of Poupinel ovens is now strongly discouraged, or even prohibited in hospitals by the Ministry of Health.

They are now mainly used in industry, especially the glass industry.

The stages of operation

The principle of dry heat sterilization is based on heat conduction. The process operates in successive stages. The heat is first absorbed by the outer layer of the instrument being sterilized. Then, it is gradually transmitted inwards, layer after layer, until it reaches the center. Once the heart of the instrument has been reached, the entire object can be considered to have reached an optimum temperature for effective sterilization.

How to use it ?

• Put the switch on “On”;
• Load the Poupinel with the instruments to be sterilized, the boxes must be open for better access to heat;
• Close and lock the oven;
• Set the temperature to be reached and the desired sterilization time;
• Once the time has elapsed, wait for the cooling to open the door.

Precautions to take

The material to be sterilized must be well washed and dried beforehand, the presence of water on the surface can interfere with the process of dry sterilization of the object.

Poupinel ovens are available in different sizes: from 1,5 liters to 60 liters. They all have the same characteristics of controls, operation and performance.

Their price varies between 250 and 850 € depending on the size.

They must comply with CE medical standards.

Other methods of sterilization

Since dry heat sterilization is now banned in the medical environment, due to its lack of efficacy on the inactivation of prions, other processes are used, in parallel or as a replacement.

Ethylene oxide

Ethylene Oxide Gas Sterilization is a cold sterilization method used for sterilizing medical instruments that do not tolerate heat: instruments containing plastic and instruments containing electronic components.

Humid heat

Autoclaves are ovens that produce moist heat under pressure, much like pressure cookers. Water vapor sent under high pressure destroys all microorganisms. Autoclaves are used to sterilize textile compounds (compresses, surgical drapes, gowns, etc.) and metal or glass instruments.

L’usage unique

Medical equipment is now more and more often for single use, which makes it possible to resolve the issue of sterilization… by circumventing the problem.