[When]...it appeared that the ferments, properly so-called, are living beings, that the germs of microscopic organisms abound in the surface of all objects, in the air and in water; that the theory of spontaneous generation is chimerical; that wines, beer, vinegar, the blood, urine and all the fluids of the body undergo none of their usual changes in pure air, both Medicine and Surgery received fresh stimulation. -- Louis Pasteur
A few words on Sterile Fields &Technique
The following introduction is meant to enlighten medical students to principle ideas of sterile technique. Though perhaps a future version will incorporate relevant hospital policy, at present one should not regard this introduction as a reflection of specific UVA protocols or SOPs.
Not just clean
Sterile (or ‘aseptic’) technique is first and foremost about minimizing possible sources of infection (nosocomial infection = an infection got while hospitalized).
Sterile means free of bugs that can infect people. Sterility will apply to SELECT surfaces of objects or to substances that will be introduced into a patient’s body. Some objects just don’t have the potential to be made sterile. Hands can be made very clean but not sterile. “Scrubs” from the locker room dispenser are not sterile, nor are surgical masks. Et cetera. The message is: Only specific, deliberately prepared surfaces or substances are considered sterile.
So follows the general idea behind STERILE FIELDS:
1. Prepare and maintain select surfaces as sterile.
2. Minimize potential sources of contamination by segregating sterile surfaces from non-sterile areas (even very clean areas!).
The space in which sterile objects may interact -undisrupted by non-sterile objects -is a sterile field. An important point to bear in mind is that a person or thing will have only a particular portion of its surface designated as sterile (and therefore within a sterile field). Every other surface is considered non-sterile, and any non-sterile surface may contaminate a sterile surface.
So, sterile fields are defined by the sterile surfaces of two O.R. things. Typically, on scrubbed surgical personnel (by “scrubbed” meaning hands washed according to O.R. protocol, donning sterile gown, sterile gloves) the sterile surface would extend (approximately) from the chest to the waist on the torso and from elbows to the tips of gloved fingers on the upper limb. The rest of the scrubbed person is not sterile and is a possible source of contamination for the sterile area.
On a patient, only the prepared surface of the body and the sterile drape are considered within the sterile field. Note that edges of otherwise sterile surfaces are not sterile, since they must contact (or appose) non-sterile objects. So, the physical edges of a sterile drape -or any surface of the drape below the space defined by the other sterile objects of the field - are not considered sterile.
A typical O.R. visit may be as follows:
1. Obtaining scrubs from the scrub-machine and changing (locker room)
2. Obtaining, donning a surgical hair cap and shoe covers (locker room)
3. Washing hands (note: short fingernails are important)
4. Obtaining, donning a surgical mask at the scrub station
5. Entering the operating room, being alert to the scrub nurse and sterile areas
6. Performing any duties with non-sterile objects (including preparation of the patient)
7. Scrubbing in
Generally, scrubbing-in means a sequence of procedures where in one obtains a sterile surface.
1. Surgical hand scrub
2. Gowning (putting on sterile, surgical gown)
3. Gloving (putting on sterile, surgical gloves)
Actions involved in these procedures are perhaps best left to captioned photographs. For now, please refer to one of the perioperative nursing texts in the bibliography for specifics regarding hand scrubbing, gowning, and gloving (e.g., pp. 136-143 in “Alexander’s Care of the Patient in Surgery”). These books are available at the Health Sciences Library.
The surgical hand scrub is performed outside the O.R. at the scrub station. Once completed, one must carefully reenter the O.R. for gowning (usually with the assistance of the scrub nurse) and gloving.
Finally, once gowned and gloved, a person’s movements must take into consideration the sterile fields. Typically, when moving, hands should be kept directly in front of the chest, but clear of the face or other non-sterile areas. Therefore, when passing O.R. personnel or non-sterile things, one’s posterior should face the non-sterile surfaces of these O.R. obstacles. Once part of the sterile field, one’s sterile surface must face the prepared surface of the patient or other sterile surfaces. Pictures within the aforementioned perioperative nursing texts provide examples for thoughtful postures and movements to preserve sterile fields.
Quote from Pasteur’s speech "Germ Theory And Its Applications To Medicine And Surgery" made to the French Academy of Sciences, April 29th, 1878. Published in Comptes rendus de l'Academie des Sciences, lxxxvi., pp. 1037-43 (translation by H.C.Ernst).
Meeker, M and Jane Rothrock. (1999). Alexander’s Care of the Patient in Surgery, 14th ed. Mosby, Inc. (UVA Health Sciences Library Call# RD 32, .3, .A43)
Fortunato, N. (2000). Berry and Kohn’s Operating Room Technique, 9th ed. Mosby, Inc. (UVA Health Sciences Library Call# RD 32, .3, .B4)