150. CCA Study Notes: Surgical Asepsis and Maintaining a Sterile Field

The Big Picture

Some procedures require equipment and supplies to stay completely free of microbes. Surgical asepsis, also called sterile technique, uses practices that keep these items sterile.

Surgical asepsis is required any time the skin or sterile tissues are penetrated. If something sterile becomes contaminated, microbes might reach the client and increase the risk of infection.

For a CCA student, the key skill is learning what keeps a sterile field sterile and what makes it contaminated.

Look for Nova Scotia CCA Notes throughout this page for current provincial guidance.

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Course Notes: Key Ideas You Need to Know

What Surgical Asepsis Means

Asepsis means reducing or eliminating potential pathogens. There are two levels, medical asepsis and surgical asepsis.

Surgical asepsis means keeping equipment and supplies free of all microbes. Another name for surgical asepsis is sterile technique.

Sterile means free of pathogens, nonpathogens, and spores.

A pathogen is a microbe that causes harm, such as infection or disease. A nonpathogen is a microbe that does not usually cause infection or disease in humans.

A sterile field is a work area free of pathogens, nonpathogens, and spores. Contamination means exposure to microorganisms, including pathogens.

When Surgical Asepsis Is Required

Surgical asepsis is required any time the skin or sterile tissues are penetrated.

Procedures that require surgical asepsis include:

• catheterization
• IV administration
• suctioning
• sterile dressing changes
• blood collection

Support workers are not normally authorized to perform these procedures. A support worker might assist with them or perform one through delegation. This makes understanding sterile technique important even when the procedure is not normally part of the support worker’s role.

Clean and Sterile Are Not the Same

A clean item is not automatically sterile.

Sterile procedures require sterile gloves and sterile equipment.

A sterile item touches only another sterile item. If a sterile item touches a clean item, the sterile item becomes contaminated.

Only sterile items belong on a sterile field. Items that contact the client during a sterile procedure must remain sterile.

Check Sterile Packages Before Use

A sterile package becomes contaminated when it is:

• open
• torn
• punctured
• wet
• moist
• past its expiration date

Do not use a contaminated item. It must be discarded or resterilized.

Safety: If you are unsure whether an item is sterile, consider it contaminated.

Handling Sterile Items

Use sterile gloves or sterile forceps when handling other sterile items.

Keep sterile gloved hands:

• above waist level
• within your sight

The sterile field and sterile items must stay above waist level and within sight. A sterile item below waist level is contaminated.

Never leave a sterile field unattended. Do not turn your back on sterile items or the sterile field. If you lose sight of an item, consider it contaminated.

Protect the Sterile Field From Airborne Contamination

Microbes in the air might contaminate sterile items and the sterile field.

Reduce this risk by:

• preventing drafts
• closing the door
• avoiding unnecessary movement
• asking other staff to limit unnecessary movement
• avoiding coughing, sneezing, talking, or laughing over the sterile field

If you must speak, turn your head away from the sterile field. Wear a mask when you need to talk during the procedure.

Do not assist with a sterile procedure if you have a respiratory infection.

Never Reach Over a Sterile Field

Do not reach over a sterile field.

Keep the Sterile Field Dry

A sterile field must remain dry. If it becomes wet, it is contaminated.

Fluids move downward with gravity. Keep wet items down. For example, raising wet hands lets water run down the arms.

When pouring sterile fluids into sterile containers, avoid spills and splashes.

Remember the 2.5-cm Margin

The edges of a sterile field are considered contaminated.

A 2.5-cm (1-in.) margin around the sterile field is contaminated.

Place sterile items inside this margin. Anything outside the 2.5-cm margin is contaminated.

PPE During Sterile Procedures

Personal protective equipment (PPE) creates a barrier between microbes and a person’s hands, eyes, nose, mouth, and clothing. PPE includes gloves, gowns, masks, and eye protection.

During sterile procedures, PPE must also protect against contact with blood, body fluids, secretions, and excretions.

What to Do if Contamination Happens

Honesty is essential during sterile technique.

If you contaminate an item or the sterile field:

1. Recognize that contamination occurred.
2. Remove the contaminated item.
3. Correct the situation.
4. Start again with sterile supplies when necessary.
5. Report the contamination to your supervisor.

Do this even when no other staff member saw what happened.

Common Mix-Ups

Wrong Idea	Better Idea
Clean and sterile mean the same thing.	Sterile means free of all microbes, while a clean item is not automatically sterile.
An item stays sterile if it drops below your waist.	Anything below waist level is considered contaminated.
A damp sterile field is still usable.	A wet sterile field is contaminated.
The entire surface of a sterile field is sterile.	The outer 2.5 cm (1 in.) margin is contaminated.
An item is safe to use when you are unsure about it.	If sterility is uncertain, treat the item as contaminated.