PRINCIPLES OF ASEPTIC TECHNIQUE

STERILITY

• Sterile or sterility means, an object or surface completely free of all living microorganisms including microbial spores.
• All nonsterile surfaces are considered potentially contaminated with pathogenic microorganisms.
• Sterility is absolute. Something is either sterile or not sterile—there is no "partial sterility."

CONTAMINATION

• Contamination is the contact between a sterile surface or object and a nonsterile item, substance, or entity. Contaminated + sterile = contaminated.
• It is an event in which a sterile item or surface has come in contact with a nonsterile item or surface
• It defines an item or surface that was previously sterile but comes in contact with a contaminant.

  For Example –

  • A sterile instrument that falls to the floor. The instrument is contaminated.
  • The surgeon's gloved hand accidentally touches the nonsterile edge of the surgical drape. His glove is contaminated.
  • The scrubbed surgical technologist accidentally punctures her glove with a suture needle. The needle is contaminated (remember that skin is not sterile).
• Gross contamination is the contamination of the surgical wound or sterile field by a highly infective source such as in the example just given.

  For Example –

  • An infected appendix has ruptured, spilling pus into the abdominal cavity. Gross contamination of the peritoneal cavity has occurred.

BARRIERS

• One of the foundation principles of aseptic technique is based on the concept of creating a barrier between the sources of contamination and a sterile surface.
• A physical barrier prevents a non-sterile surface from touching a sterile surface. In other words, it contains (encloses) or separates a source of contamination.

  For Example –

  • Hair caps and masks are barriers that contain sources of contamination (hair, dander, exhaled air).
  • A sterile table cover provides a barrier between the nonsterile surface of the table and sterile equipment placed on the cover.
  • A chemical barrier is produced by the residual effect of antiseptics used during patient skin preparation and the surgical scrub or hand rub.

SURGICAL CONSCIENCE

• Admitting and reporting any break in aseptic technique demonstrates a high level of professional maturity and surgical conscience.
• All members of the surgical team are jointly responsible for reporting and responding to breaks in aseptic technique so that steps can be taken to mitigate the risk of infection.

  For Example –

  • If a sterile team member contaminates the field without knowing, others may quickly report the break—"Dr. X, your glove touched the anaesthesia screen."
  • If the gloved hand is contaminated, the glove is changed as soon as possible.
  • If irrigation fluids are contaminated, they are discarded and new sterile basins and fluids are obtained.
  • In the case of gross contamination, this may mean starting the patient on intravenous antibiotics.
• One of the most important roles of the scrubbed surgical personnel is to protect the field; this includes watching for breaks in technique and reporting them quickly.

THE PRINCIPLES OF ASEPTIC TECHNIQUE

• Aseptic technique encompasses the practices used to create, protect, and maintain the surgical field.
• The objectives of the technique are containment, confinement, reduction, and elimination of microorganisms to prevent contamination of the sterile field.
• Techniques are based on the central principle that microorganisms transmit disease from objects, surfaces, air, and dust to patients and personnel.
• The sterile field is the physical area starting with the surgical incision at the centre and extending to include the patient drapes, sterile instrument tables, and any draped equipment such as the operating microscope. It also includes scrubbed team members.
• The sterile field is created using specific rules and standards. The following practices pertain to any situation in which a sterile field exists:

1. Sterile surfaces contact only sterile surfaces; nonsterile surfaces contact only nonsterile surfaces.
2. A sterile item is considered sterile only after it has been processed using methods that have been proven effective and that yield measurable results.
3. Sterile drapes, gowns, gloves, and table covers are barriers between a nonsterile surface and a sterile surface.
4. The edge of any sterile drape, wrapper, or covering is considered nonsterile.
5. Sterile liquids in bottles with an edge (lip) that is protected with a sealed sterile cap may be delivered directly from the bottle into a sterile container on the field.
6. If any doubt exists about the sterility of an item, consider it contaminated.
7. The draped patient is the centre of the sterile field during surgery.
8. Sterile gowns are considered sterile only in front from midchest to table level.
9. Sterile personnel must pass other sterile personnel back to back or front to front.
10. Sterile tables are considered sterile only at table height.
11. Sterile personnel remain within the immediate area of the sterile field.
12. Nonsterile team members never lean over or reach over a sterile surface to distribute sterile goods to the field. They do not pass between two sterile surfaces.
13. Movement is kept to a minimum during surgery.
14. Drapes and linens should be handled as little as possible and with a minimum of movement.
15. Talking is kept to a minimum during surgery.
16. Moisture carries bacteria from a nonsterile surface to a sterile surface.
17. The sterile field is created as close as possible to the time of surgery and is monitored throughout the procedure.

*****