What is Aseptic Technique?

Aseptic technique is a means of preventing quantities of pathogenic microorganisms from being introduced to surgical wounds by hands, surfaces and equipment.

Asepsis is defined as an absence of pathogenic microorganisms on living tissue, therefore aseptic technique is the way this is achieved.


Aseptic technique is probably the most commonly practiced infection prevention technique used in healthcare. Every wound dressing and surgical operation – however minor – uses strict application of aseptic technique to protect the patient in order to reduce the potential for infection in the wound. 

Many other items which may be put into a patient such as a urinary catheter or intravenous line are also placed using an aseptic technique and sterilised products.

The patient may also be the source of infectious microorganisms which can be passed on to the healthcare worker or visitor.  

It is good practice to ensure that those practicing aseptic technique have been trained in the principles and competency monitored.  

Infection Prevention and Control

In surgery, strict aseptic technique is used to protect the patient from infection.

The surgical team prepare themselves by scrubbing their hands and arms using an evidence-based method of preparation using a specially-prepared antimicrobial soap solution to reduce the transient and resident flora on their hands and arms. These are then covered using a prepared sterile textile or enhanced paper gown and sterile gloves. 

The environment is prepared using re-usable equipment that has been sterilised using a variety of different techniques such as irradiation or steam autoclaving. Single use products are not re-used and are appropriately disposed of in the waste system.

Prior to their arrival in surgery, the patient has had a shower or bath which reduces some of their skin organisms. They are further prepared by using an antimicrobial agent on the skin before they are draped in sterile enhanced paper drapes or sterile textiles, once in the surgical environment.  

The equipment trolley is prepared by a person clothed in sterile gown and gloves, and only sterile equipment may touch the trolley once it is covered, thus maintaining the sterile field.

Post-operatively, NICE recommends that wound dressings are not removed for 48 hours. Any dressing which needs to be replaced, should only be done using an aseptic technique.

The complete absence of viable, living organisms – an aseptic state.

Creation of a Sterile Field

All horizontal areas of the “sterile field” are deemed to be free from microorganisms as far as can be achieved. Drapes which hang vertically down from the surgical site, instrument trolleys and staff are not considered to be sterile.

So, if one looks at an image of an operating theatre, ready for surgery with all sterile drapes in place, staff gowned and trolleys laid, you may be told not to touch anything that is green, or blue in some cases dependent on the colour of the drapes used in that facility; which are the areas deemed sterile and which deemed not sterile, but to be treated as such.

Wound Care on the Ward

Nurses are taught to use a non-touch technique when they manage a patient’s wound on the ward. It is tricky to learn but avoids any contamination of the wound.

The vast majority of patients are discharged from the ward before they show signs of getting a wound infection. However, those with the most seriously infected wounds are re-admitted to hospital for management.  

Trolley Prep and Alcohol Products

The trolleys used for instruments and other sterile requirements used during surgery or a sterile technique all need to be clinically cleaned both before and following use. Most hospitals use wipes for this task, usually impregnated with 70% isopropyl alcohol or an equivalent. The trolley surfaces and legs are wiped down and the solution allowed to dry/evaporate prior to use.

Surgical Site Creation

After the patient’s skin has been cleaned and prepped, drapes are used to surround the intended surgical incision site. These are carefully placed by members of the surgical team, who are gowned and gloved.

The drapes are secured and equipment which is sterile, as well as scrubbed personnel, move in towards the patient and as above the sterile field has been created. Horizontal surfaces are considered the sterile field.  

Avoiding Contamination and Cross-Infection

Maintenance of the sterile field is ensured only if only sterile persons touch sterile items or areas. Any breach of this by people or equipment contaminates the field and has the potential of causing the patient an infection. 

It is an unwritten rule in hospitals that if there is any breach of sterility by a member of staff, then they must own up to it, ethically, and in order to protect the patient. Mistakes can be forgiven, if they are divulged. 

The number of people creating movement in the area of the sterile field creates little eddies of possible airborne microorganisms. There is no definitive number, but as the mass of people increases so does the number of colony forming units in the atmosphere. This is due to the number of skin cells we all lose as we move around – the cells can carry bacteria in the air with them.

Keeping the doors to the operating rooms closed, as far as possible so that the ventilation can work effectively is another method of reducing possible infection to the patient.

Your Interaction with the Sterile Field

It is your responsibility to speak up if you touch or contaminate the sterile field or if you observe that this has happened. Remember that the patient’s safety is central to the procedure and you should feel confident to advocate on their behalf.

To reduce and avoid the risk of causing contamination of the sterile field, stand back from the team at the operating table, keep out of the way but pay attention and show interest and engagement.

Opening Sterile Products

You may be in the clinical area to support the introduction of a new sterile product from your company. Best practice would suggest that any skills required to open the product from its external covering and presenting it in a sterile manner has been taught to staff in advance of using it in the clinical area.

Therefore you should have no need to be undertaking this or any other opening of sterile products in clinical areas. Staff need to learn how to do it themselves for when you are not present. You will not always be there and it would be negligent to leave them not knowing how to deal with your products, so do not do it. Remember that if it’s a costly product and you drop it, then the cost is the company’s – if they drop it, they will have to open a new one.

You may see staff tipping sterile products onto a sterile trolley because the scrub practitioner is busy. This risks the “dirty” packaging touching the sterile trolley or of the contents being dropped. This practice is not recommended for those reasons. Some staff will reach over with an instrument to remove the product from the packaging if it is suitable, light and stable to be managed in this manner.

It may be that an item from your company is removed from the patient or fails in use and you are asked to take it to be returned to the company. You should ask that it is put into a receiver and handed out from the sterile field to a skilled member of staff, who will instruct you on how to deal with it.

Disposal: Waste Management

Managing the waste products from a hospital is a complex and costly undertaking. Essentially, waste is segregated at source and is handled according to how potentially infectious or toxic it might be to the handlers and others into the future.

Waste containing any possible body fluid or blood, including old dressings from patients is categorised as clinical waste and is contained in a yellow or orange bag which is sealed and labelled at source. It is collected and disposed of by incineration, usually at a site away from the hospital.

Black bags contain clean domestic waste from hospitals such as the vast quantities of packaging and paper that are discarded every day. Black bag waste goes to landfill and costs the healthcare system and the tax payer large amounts of money. 

Sharps are separately disposed of as they can cause harm to handlers. They are contained in especially designed containers and disposed of by incineration.


This ends the course. You can now continue to the exam. 


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