ASEPSIS: HISTORY AND ASEPTIC TECHNIQUE - MEDICINE - 2024

The term asepsis refers to the reduction of pathogenic microorganisms (capable of causing infection) to a minimum through different techniques; among them the use of bactericidal solutions that eliminate germs from the skin and wounds of the patient.

Another important element of asepsis is the sterility of the material to be used in the procedures (needles, scalpel blades, sutures, instruments, etc.); sterile material being understood as that which is 100% free of microorganisms.

In this sense, sterilization methods can be applied to materials (surfaces, sheets, instruments, etc.), but not to people, since to date no method has been described that can eliminate 100% of microorganisms of a living being safely.

History of asepsis

It is no secret to anyone who has been in a hospital, bioanalysis laboratory or dental practice that the materials used are handled with great care to keep them “sterile” and free from contamination.

But this was not always the case, just over 150 years ago (mid-19th century) materials were hardly cleaned with water, patients were seen without gloves, and doctors did not even wash their hands between patient and patient.

In our eyes it seems like an outburst, but at that time it was a common practice, since they did not have the knowledge that we currently have and the aseptic and antiseptic procedures that are known and applied routinely today had not been described.

It is therefore no surprise that at that time postoperative infections, including infections after childbirth, were one of the main causes of mortality in healthcare centers.

The development of Microbiology

The existence of microorganisms not detectable with the naked eye has been known since the time of Anton van Leeuwenhoek, who in the seventeenth century described small beings that he called "animáculos", using a combination of magnifying lenses (early microscopes). However, until the end of the 19th century the association between these organisms and diseases was established.

Such an association was established thanks to the work of the eminent French scientist Louis Pasteur (considered the father of Microbiology), who made the first scientific descriptions of microorganisms and developed the first vaccines, laying the foundations for a new branch of biology.

In parallel, the findings of the German scholar Robert Koch, who managed to isolate the microorganism responsible for tuberculosis, opened up new horizons on understanding the origin of diseases, and even better, how to prevent them.

Antisepsis concept

It can be considered that the development of the concept of antisepsis as we know it today began with the reports of the Hungarian physician Ignaz Semmelweis, who indicated that hand washing between patient and patient drastically reduced infections after childbirth.

This observation was scorned by the scientific community of its time (first half of the 19th century) for lacking scientific bases to support it, despite the fact that it managed to reduce maternal deaths from infections to less than 1%.

By the end of the 19th century, several years after Semmelweis died, the English surgeon Joseph Lister put all the pieces of the puzzle together.

He concluded that Pasteur's findings were the scientific basis for what Semmelweis proposed years ago, developing from this knowledge the first sterilization techniques in the operating room using phenol.

Aseptic technique

Aseptic technique is known as the set of measures implemented to minimize the risk of contact between the patient and pathogenic microorganisms during invasive medical procedures.

Aseptic technique can be divided into several parts:

1. Placement of sterile fields (barriers) that isolate the patient from the surrounding environment
2. Sterilization of surgical material (instruments, sutures, needles, etc.) and of the areas where invasive procedures are performed
3. Preparation of the patient's body area to be intervened by using antiseptic solutions designed to eliminate as many potentially dangerous microorganisms as possible.

The correct observation of the three previous phases guarantees that the risk of infection is reduced to a minimum; For this, it is important that all the material is handled with sterile gloves and within a well-defined field known as “sterile field”.

Any material that accidentally comes into contact with the hand not protected by the sterile glove (because it broke) or touches a surface not covered by the sterile field (table, stretcher, floor), must be discarded and cannot be used again until it has been sterilized again.

Steps for the correct implementation of the aseptic technique

Aseptic technique is not an isolated act or measure, on the contrary, it is made up of a series of procedures that involve from the patient to the material, through the healthcare personnel and the areas where invasive procedures are performed.

Thus, the implementation of the aseptic technique takes place at different levels, namely:

Medical and paramedical personnel

1-Washing of hands prior to the execution of the procedure, using bactericidal solutions (iodine-povidone, chlorhexidine, etc.)

2-Wear sterile clothing (surgical jumpsuit and gown)

3-Use of sterile gloves

4-Avoid contact with non-sterile surfaces during the execution of invasive procedures

5-Use of boot covers on footwear

6-The hair must be collected with a surgical cap, the same as the beard

7-Use of mask

Patient

1-Preoperative washing with soap and water of the whole body

2-Remove all clothing before entering the procedure area. The patient should only wear disposable clothing suitable for use in sterile areas.

3-Shaving the area to be operated on (when applicable) before the procedure and entering the surgical area.

4-Preparation of the area to be intervened with antiseptic solutions (iodine-povidone, chlorhexidine, etc.)

5-The hair must be collected with a cap suitable for this purpose.

Surfaces and furniture

1-All furniture as well as the procedure area (surgery room, delivery area, etc.) should be washed with soap and water regularly

2-Use of disinfectant solutions (sodium hypochlorite, quaternary ammonium derivatives, etc.) to clean all the furniture between patient and patient.

3-Sterilization of the surgical area (including furniture) once a day using ultraviolet light lamps (the room must be closed and without personnel inside during this operation)

4-All surfaces, including the patient's body, must be covered with sterile drapes during the execution of invasive procedures.

Instruments and equipment

1-All instruments must be sterilized with an effective technique according to their characteristics.

Sterilization by dry heat (oven) or wet (autoclave) for metallic instruments that does not deteriorate with heat.

Ethylene oxide sterilization for rubber or precision material that could be altered by heat (rubber tubes, optics)

Sutures, scalpel blades, catheters, and other supplies are usually factory sterile (usually sterilized with UV light or ethylene oxide); in double packaging. The NON-sterile outer package should be opened by an assistant, dropping the (sterile) inner package into the field.

2-The material to be used should always be handled with sterile gloves and within the area delimited by the sterile fields.

3- Do not make contact with any surface that is not covered by the sterile field.

3-All potentially contaminated material must be removed from the area

4-The disposable material, the suture remains and the scalpel blades that were used must NEVER be re-sterilized. All this material must be discarded using bags and containers designed for this purpose.

The correct execution of all these steps guarantees that the risk of infection is minimized, hence the importance of their rigorous and systematic execution by all members of the health team, especially those involved in the execution of invasive procedures.

In addition, constant research must be carried out in order to improve these techniques so as to constantly improve the ability to minimize the risk of infections associated with invasive procedures.

Much has happened since the days when puerperal fever killed 1 in 3 women in labor.

Today, thanks to the constant advancement of science, it is possible to perform major invasive procedures with a minimal risk of infectious complications, largely thanks to the correct execution of aseptic technique.

References

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