Preparation of the Surgical Team

Surgical personnel are an important source of microbial contamination during surgery. Careful preparation of the surgical team and nonsterile personnel reduces the number of bacteria in the surgical suite but does not eliminate them. A correlation has been noted between the number of people, their movements, and the number of airborne bacteria in a surgical suite. To minimize contamination during surgery, strict guidelines should be followed regarding surgical attire for all surgical room personnel, including observers. If possible, surgical room personnel should be reduced to only those essential for anesthesia or surgical support.

Surgical Attire

All those entering the operating room suite should be appropriately clothed, regardless of whether surgery is in progress. To minimize microbial contamination from operating room personnel, scrub clothes rather than street clothes should be worn in the operating suite. With two-piece pant suits, loose-fitting tops should be tucked into the trousers. Tunic tops that fit close to the body may be worn outside the trousers. The sleeves of the top should be short enough to allow the hands and arms to be scrubbed. Pants should have an elastic waist or drawstring closure. Nonscrubbed personnel should wear long-sleeved jackets over their scrub clothes. Jackets should be buttoned or snapped closed during use to minimize the risk of the edges inadvertently contaminating sterile surfaces. Scrub clothes should be laundered between wearings and changed if they become visibly soiled or wet to prevent transfer of microorganisms to the surgical environment. Wearing scrub clothes outside the surgical environment increases microbial contamination. If a scrub suit must be worn outside the surgery room, a laboratory coat or single-use gown should be used to cover it. If a scrub suit becomes visibly soiled, contaminated, and/or penetrated by blood or other potentially infectious material, it should be changed.

Other surgical attire includes hair coverings, masks, shoe covers, gowns, and gloves. Hair is a significant carrier of bacteria; when left uncovered, it acts as a filter and collects bacteria. Because shedding from hair has been shown to affect the surgical wound infection rate, complete coverage is necessary. Caps should completely cover all hair, and masks should cover the mouth and nostrils. Sideburns and beards require hoods (Fig. 6-1) for complete coverage. Skullcaps that fail to cover the side hair above the ears and the hair at the nape of the neck should not be worn.

FIG 6-1 Facial hair and sideburns should be covered with a hood.

Any footwear that is comfortable can be worn in the surgery area. Although the value of shoe covers has recently been debated, the current recommendation is that they should be donned when first entering the surgical area and should be worn when leaving it to keep shoes clean. New shoe covers should be donned upon returning to the surgical area. Shoe covers generally are made of disposable materials that are water repellent and tear resistant. Because of the abundance of animal hair in veterinary hospitals, changing shoe covers immediately before entry into the surgical theater may decrease the amount of hair tracked into the operating room by surgical room personnel.

Masks constructed from lint-free material containing a hydrophilic filter web sandwiched between two outer layers should be worn whenever entering a sterile area. Their major function is to filter and contain droplets of microorganisms expelled from the mouth and nasopharynx during talking, sneezing, and coughing. Masks must be fitted over the mouth and nose and must be secured in a manner that prevents venting. The dorsal aspect of the mask is secured by shaping the reinforcing top edge tightly around the nose. Although it has traditionally been recommended that all individuals entering restricted areas of the operating room suite wear a mask when open sterile items and equipment are present, a recent study found no difference in surgical site infection rates when nonscrubbed operating room personnel did not wear a face mask (Webster et al, 2010).

Surgical gowns may be reusable and made of woven materials (usually cotton), or they may be disposable. A recent study found no difference in contamination and infection of the surgical site between fabric and nonfabric scrubs (Burgatti and Lacerda, 2009); however, another study found that single-use gown and drape sets provide the highest cost/benefit rates in a human hospital setting (Baykasoglu et al, 2009). Disposable (single-use) gowns are nonwoven and are made directly from fibers rather than yarn. Loosely woven, all-cotton fabric, type 140 muslin commonly is used to make reusable gowns. This fabric is instantly permeable to bacteria when it becomes wet. A more expensive alternative, 270 pima cloth that has been treated to produce a durable, water-repellent finish, provides a better bacterial barrier. Fifty/fifty polyester/cotton blend cloth is available as a tightly woven fabric that resists bacterial penetration. Laundering woven gowns widens the fabric pores, diminishing their effectiveness as microbial barriers. Nonwoven gown materials include olefins and polyesters. The number of microorganisms isolated from the surgical environment is lower when disposable, nonwoven materials are used.

Surgical Scrub

All sterile surgical team members should perform a hand and arm scrub before entering the surgical suite. In 1840, the Hungarian obstetrician, Ignaz Phillip Semmelweis, discovered that antiseptic hand washing could reduce patient deaths from pathogens transmitted by hands. He reduced the maternal mortality rate from puerperal fever by about 90% over a 3-year period by initiating hand washing before touching hospital patients. Hand antisepsis was further advocated by Joseph Lister, Professor of Surgery at the Glasgow Royal Infirmary, in 1860 to promote asepsis and reduce surgical site infection. Lister initiated the first known disinfection program wherein the clinical environment and all equipment were cleaned with carbolic acid. Additionally, the surgical team was asked to wash their hands in a solution of 5% carbolic acid before undertaking surgery.

The objectives of a surgical scrub include mechanical removal of dirt and oil, reduction of the transient bacterial population (i.e., bacteria deposited from the environment), and residual depression of the skin’s resident bacterial population (i.e., bacteria persistently isolated from the skin) during the procedure. Relying on gloves alone (without a surgical scrub) to prevent microbial contamination is not recommended because many surgical gloves have holes at the completion of surgery and the percentage may increase for long or difficult surgeries. Glove defects occur in approximately one-fourth of surgeries in a veterinary setting. Significantly more defects have been found to occur in non–soft tissue procedures and in gloves worn on the nondominant hand. Glove defects are more likely to occur in procedures lasting longer than 60 minutes. It is important to note that the individual performing the surgery typically is unable to accurately predict the presence of a defect in his or her gloves.

NOTE • Given the high rate of glove defects in longer surgical procedures (especially orthopedic procedures), you may wish to consider changing gloves every 60 minutes or double-gloving.

Scrub Technique

Three main developments in surgical hand antisepsis have occurred in the past decade. These include (1) no longer using scrub brushes (Fig. 6-2), (2) the introduction of alcohol rubs (Box 6-1), and (3) a reduction in the duration of the scrub. In veterinary schools, instructions for surgical hand antisepsis have, until recently, included scrubbing the hands and arms with a brush. This practice is no longer recommended because studies have determined that scrubbing hands and arms results in skin damage and increased bacterial counts. Scrubbing with a brush has been demonstrated to remove epidermal layers, increase shedding of bacterial squamous cells, increase (not decreases) microbial counts, and change microbial flora, Thus, most experts agree that the time-honored convention of vigorously scrubbing off the uppermost layers of skin with a brush is not only unnecessary, but also unwise. Investigators in one study concluded that nail brushes and nail picks used during surgical hand scrubs do not decrease bacterial numbers and are unnecessary (Tanner et al, 2009). In this study, the following three surgical hand scrub protocols were compared: chlorhexidine only; chlorhexidine and a nail pick; and chlorhexidine and a nail brush. No statistically significant differences in bacterial numbers were found between any two of the three intervention groups.

Box 6-1 Surgical Hand Antisepsis/Hand Rub With an Alcohol-Based Surgical Hand Rub *