Currently the Center for Disease Control (CDC) recommends 15 air exchanges per hour for operating rooms (CDC 2008). In addition operating rooms should have a laminar air flow system. Studies have shown that laminar air flow significantly reduces the number of particles in the air. If a laminar air system is not possible, a positive air flow (air flows out when the door is opened) will aid in keeping irritants out of the operating suite. Incoming air should be at the ceiling level while outgoing air should be at the floor level. Whatever type of system is used, proper care and maintenance is critical in achieving optimal efficiency. Cleaning of the system (ducts, grates, filters, and drain pans) will increase the efficiency of the system. Annual assessment of air quality in the operating room should also occur.

Traffic in the operating room is an often overlooked situation. People just “sticking their head in” to ask a quick question, anesthesia personnel entering and exiting the room frequently, circulating technicians being unprepared for a case and having to leave and re-enter the room numerous times with equipment, are all examples of traffic that can be avoided. Minimal movement in and out of the operating room is obviously the ideal. Once the patient has been moved into the room, positioned on the table, and has received the final sterile prep, people moving around should be minimized. Especially true with joint arthroplasty, no opening of the operating room door should occur unless there is an emergency. Since joint replacement cases are extra sensitive to surgical site infections (SSI), every effort to reduce the introduction of potential pathogens needs to be observed.

Before the first case of the day, the furniture in the operating room needs to be arranged so a good traffic flow is possible. Back tables should be pushed up against the walls; cautery units and suction units should be plugged in and be ready for use, but pushed back away from the surgery table. The anesthesia machine should be placed from where it will be used. For most cases, it will be at the head of the table. For some cases however (i.e., ophthalmic procedures or other head/facial procedures), that may mean placing the anesthesia machine at the back of the table. The surgery table should be at the height of the transport table for ease of transferring the patient. The height of the surgery table for the surgeon can be adjusted after the patient is positioned. All flat surfaces including overhead lights should be damp dusted with a lint free rag and 70% isopropyl alcohol or commercially available disinfectant wipes.

After the last case of the day, the surgical suite should undergo a more vigorous cleaning. All furniture should have a physical scrubbing done. All surfaces, including wheels or casters should be freed of any debris (hair, suture ends, etc.). All shelves of equipment should be scrubbed as well. All equipment such as cautery, laser, and suction machines should be wiped down with a disinfectant. Linen hampers, kick buckets, sponge basin stands, and so on should be wiped down and disinfected as well. Floors should be wet vacuumed. Mopping should be avoided unless clean mop heads and fresh solution is used on each room to prevent the spread of bacteria. Air intake grills, door handles, and window sills should be wiped down. Walls and ceilings should be checked and spot cleaned as needed.

A dilute bleach solution of 1:32 (1 oz. in 32 oz of tap water) is an effective disinfectant. Although this is inexpensive, the disadvantages may outweigh the cost effectiveness. Once mixed, it is highly unstable and light sensitive. So it needs to be made fresh every day and stored in an opaque spray bottle. The mechanism by which chlorine works is by a denaturing of proteins due to their electronegative nature. It is considered a broad spectrum disinfectant; however, it isn’t a good cleaner. So areas need to be cleaned before being disinfected. Bleach does not perform well in the presence of a detergent or an organic material and so surfaces must be free of those products. Finally, as is true with many products, it requires a 10-minute contact time to reach full effectiveness.

Potassium peroxymonosulfate (Trifectant®) claims bacteriocidal, virucidal, and fungicidal capabilities. Its method of action is by the denaturation of proteins and lipids of organisms. Once mixed to the 0.5, 1 or 2% solution it is stable for 7 days. It also requires a 10-minute contact time, but is an effective cleaner as well as disinfectant. Some references claim unreliable performance against dermatophytes. At the time of writing, California allowed limited use of this product.

Phenols (One Stroke Environ®) are broad spectrum disinfectants that are formulated in soap solutions so as to improve cleaning potential. Phenols are known to maintain activity in the presence of organic material as well as hard water. While 5% concentrations are bacteriocidal, tuberculocidal, fungicidal, and virucidal for enveloped viruses, concentrations greater than 2% are highly toxic to all animals, especially cats. This contradiction requires the discussion/decision of the use of this product in veterinary hospital situations.

Hydrogen peroxide is one example of an oxidizing agent found in some veterinary disinfectants. Accel® Disinfectant is one product for veterinary clinics. With good effectiveness against 26 organisms including Trychophyton mentagrophytes, it also has good cleaning, sanitizing, and disinfecting properties. This agent is available in concentrate, ready-to-use spray bottles, and convenient saturated wipes.

Regardless of the type of disinfectant chosen, there are some very important things to remember. First and foremost is to read and follow the directions on the label! All too often in veterinary medicine, we inaccurately dilute chemicals based on shortage of time, no measuring device readily available, or historical visual assessment (“make it a light green color”). Improper dilution can affect the health and safety of both workers and patients as well as the overall efficacy of the products. Disinfectants will not act the way they are expected to act when improperly diluted. This inaccuracy can lead to the unintentional spread of potentially lethal organisms.

Application of the disinfectant must be done as directed by the manufacturer in order to achieve the expected action. Whether sprayed on, wiped on, mopped on, or foamed on, inappropriately applied products are ineffective.

To achieve microorganism kill/control, the chemical must also be left on the surface for the directed time. Spraying a table top and wiping it right away does practically nothing. Following the manufacturer’s instructions is imperative. Many chemicals are required to be in contact with the surface 5–10 minutes, but reading instructions for use will identify the specific time. After the proper duration of contact, completely drying the surface is critical. Often this step is “short cutted” and the surface is left damp. Moisture can actually counteract the efficacy of the products as it promotes bacterial growth, therefore making sure that the surface is dry is essential.

Patients having a surgical procedure that involves the sensory organs – eyes, ears, tongue, or facial bones – are more challenging to prep. Special anatomic configurations as well as extra sensitive tissue require a special approach.

Depending on the proposed incision site, there are various methods or patterns for cleansing the skin that can be utilized. For abdominal, thoracic, neurologic, or lump/mass removals, a target pattern should be used. It is aptly named the target pattern because when properly executed, it resembles a target or bulls eye. Starting at the center of the clipped area (which should be the proposed incision site), the skin is cleansed with surgical scrub applied in a linear, back-and-forth movement. When using a sponge, it is advantageous to fold the corners of the sponge to the center to better control the surface area of the sponge touching the patient. There need not be excessive pressure placed on the skin. In fact, too much pressure can result in abrading the skin which can create a breeding ground for bacteria and actually compromise the incision. If redness or capillary oozing appears, the amount of pressure being exerted by the person prepping must be greatly reduced to the point of barely touching the skin. Contact time with the surgical scrub is what affects the effectiveness, not the amount of pressure used to apply the product. After constant contact with the proposed incision site (about 15 seconds), the sponge continues to be moved in a small back-and-forth motion while moving outward from the center to the periphery of the clipped area. If the sponge becomes contaminated (by hair or other organic material), it should be discarded and a new sponge obtained. The new sponge should begin where the old one ended and continue moving in an outward motion toward the hairline. Once the sponge touches the hair, it may continue to be used if only touching hair (Fossum, T. 2007). The entire area that is clipped should be scrubbed. After the initial scrub is completed, a decision needs to be made. Some surgeons prefer to have the site scrubbed two more times with the surgical scrub before rinsing with a rinsing agent. This approach provides a constant contact time. Other surgeons prefer to have the site scrubbed once, rinse with either 70% Isopropyl alcohol or sterile water/saline, then scrub again, then rinse, then repeat the cycle one more time. This approach has interrupted contact time, but it is easier to remove all the scrub detergent from the skin. There has been no proof that one method is more beneficial than the other as long as the recommended contact time is achieved.

The rinsing agent should be applied to the shaven area using the same target pattern. If using sterile water/saline to rinse, a good squeeze of the sponge, to remove excess fluid, will be helpful. This will help decrease excessive sudsing as mentioned previously, which can hinder complete removal of the scrub agent. It is important that all detergent be removed from the skin as it can cause tissue irritation if transferred to internal tissues. The clipped area needs to be cleansed at least three times to meet the essential contact time without excessive drying or abrading of the skin. If however, after checking the rinse sponge of the third cycle of cleansing, there is still dirt being removed, cleansing should continue until the rinse sponge is clean. Most small animals will be clean after the three cycles, but animals that live in an area where they are exposed to more dirt (outside kennel, farm) or those involved in a trauma (hit by car, penetrating wound) may need the additional cleansing. In an ideal situation, at this point the patient would be transported to the surgery room, positioned on the surgery table, and then have a sterile prep performed. However, quite frequently this doesn’t occur. If no sterile prep is performed, a final application of paint solution is applied, using the same target pattern. Paint solution may be applied with a spray bottle instead of with a sponge, although the disadvantages outweigh the advantages. Application with a spray bottle results in the solution falling on surfaces not intended to be sprayed (patient’s fur, table top, and floor) and causes a mess. Also, application with a spray bottle may mean the solution is sprayed in uneven amounts on the animal’s skin, which may mean not all solution is dry before surgery begins. Although spray application is accomplished quickly, this is the only advantage. Application of the final solution with a sponge allows for a controlled, even application of solution. However applied, the solution must be allowed to fully dry prior to draping and the incision is made to allow the product to perform to its full potential. The patient can then be moved into the surgery room, taking special care not to contaminate the prepped area. At a minimum, another final paint solution application should occur after final positioning on the surgery table.

Patients having surgery on any limb will most likely need an orthopedic prep. This method of skin preparation offers the surgeon the ability to have full circumferential access to the limb as well as having the ability to handle and maneuver the limb as needed during the procedure.

Perianal/perineal procedures are generally prepped utilizing a modified target pattern. Once the clipping and vacuuming is complete, the next step is the placement of a purse string suture in the anus. This is done to help eliminate the leakage of fecal material onto the surgical field. Unless the surgeon requests that this need not be done, it is a standard inclusion in the patient preparation. Depending on the type of surgery being performed, the anal sac openings may or may not be contained within the purse string suture. Anal sacectomy surgery generally requires the anal gland openings be left outside of the suture, or within the surgical field. However, some perineal surgery (i.e., perineal herniorraphy) will require anal sac opening inclusion within the suture pattern. Most urinary related procedures such as episioplasty or perineal urethrostomy surgeries will also encourage anal gland openings within the purse string. In the case of anal sac carcinoma, no purse string pattern may be placed at all in order to provide the surgeon with full access to the entire gland. It is best to check with the surgeon prior to placement of the purse string if there is any doubt. Some people find it easier to place this suture with a straight needle, although a curved needle certainly can be used, as long as the suture is 2–0 or 3–0 in size. Since it is a limited term suture, whether the suture is absorbable or non-absorbable is not an issue, but a monofilament is preferred. In this situation, placement of this stitch is not a primary wound closure, nor a curative measure, so it should be allowed by most jurisdiction’s Practice Acts. If any doubt arises regarding the legality of a credentialed veterinary technician performing this procedure, the Practice Act should be consulted. To place the suture pattern, start first by looking at the anus and imagining it as a clock face. With the needle at the 11 o’clock position take a superficial bite and have the needle exit at the 1 o’clock position. Starting the next bite where the previous one exited the skin, drive the needle superficially and exit at the 5 o’clock position. For the ventral placement, enter the skin at 5 o’clock, drive the needle superficially and exit at the 7 o’clock point. The final bite begins at 7 o’clock and moves in a dorsal direction, superficially and exits at the 11 o’clock point. Superficial placement is imperative for all the bites, but especially for the lateral stitches to avoid inadvertently penetrating the anal glands. In essence a “box” has been placed around the anus. Pull the suture tight to cinch down the anal opening and tie the suture. A simple square knot is sufficient. Cut the suture tails long enough to be able to find them, but not so long they interfere with the procedure. A bold note should be made on the anesthesia sheet or the surgical report indicating the placement of the purse string. This note will act as a reminder to remove the suture post procedure, but before recovery.

After the purse string stitch has been completed, the prep can begin. Working from clean to dirty areas, the clipped area lateral to the anus should be scrubbed with the target pattern. Using a new sponge for each side, perform the target pattern until hair is touched. Use a new sponge and scrub just the anus, then discard that sponge. This modified pattern is repeated until the rinse sponge is free of dirt, with a minimum of three repetitions. The appropriate contact time must also be met. The final solution is applied using the same pattern.

Multiple styles of solid warming pads that can be used are also available. Many of the pads deliver a low voltage current to the solid pad. Internal sensors regulate the temperature of the pad and greatly reduce the risk of hot spots or uneven heating. The highest setting on these pads should not be used unless there is a towel between the patient and the pad. Some models have an automatic shut off which inhibits thermal burns as well. Some of the styles of solid pads can be wrapped around (envelope) the patient, which in turn results in less hypothermia.

Any person entering the surgery room must have on the appropriate attire. Clean scrubs, with the top tucked into the pants, an appropriate head covering and shoe covers or facility dictated footwear should be a minimal dress code. Personnel in the operating room, whether they are scrubbed in or not, must also adhere to several personal hygiene rules. Bathing or showering should occur everyday. The use of fragrance or cologne should be minimal if at all. With increased sensitivity to fragrance by many people, it is a simple consideration not to heavily apply a fragrance. More importantly, if the room or area is filled with the odor of cologne, the anesthetist will have a difficult time detecting any odor of inhalant gas, which may indicate a leak in the anesthetic system. Finally, due to the increased sensitivity of the smelling sense of animals, heavy odors may be irritating to the patients.

Jewelry worn should be minimal and simple. If acting as the surgical assistant, no rings, watches, or bracelets can be worn. Even necklaces such as a simple chain are discouraged. Earrings should be removed or not worn at all. Some facilities allow small post-style earrings to be left in the ear lobes, but never should hoops or large dangling earrings be worn. Circulating technicians may have simple band style rings and watches left on. Rings with large precious gem stones risk damage from chemicals or getting caught on equipment and would best be left at home. Earrings may be left in and should be a small post-style earring. Simple single chain necklaces may be left on.

Fingernails of all surgical team members should be short, well groomed, and clean. Nails should not be longer than the pad of the finger. Long fingernails can cause pain to feline patients while scruffing them and can puncture surgical gloves. Artificial nails and/or nail polish are strictly prohibited. Chipped or flaking nail polish may contaminate the field, or worse, harbor bacteria that may infect the patient.

Members of the surgical team that are scrubbing in need to perform a surgeons hand scrub or rub. A hand rub can be employed for subsequent surgical cases, after a hand scrub has been performed for the first surgery of the day. Details regarding the hand rub are discussed later in this section. A surgical scrub or hand rub is performed in addition to the use of the sterile gown and gloves. The hand scrub is a specific method of cleansing the hands, wrists, and forearms of a person who will be wearing a sterile gown and gloves. A surgical scrub, or cleansing, is performed in addition to the use of the sterile gown and gloves. It has been reported that the overall incidence of glove defects is 23% and glove defects increase as the duration of the procedure increases. Since the presence of glove defects can often be undetected, the surgical hand scrub is an essential step. Products used for a hand scrub must be rapid acting, should be effective against a broad spectrum of bacteria, and should be nonirritating as well as effective at inhibiting bacterial growth. There are three products that may be used for this procedure – Povidone-Iodine, Chlorhexidine and Chloroxylenol (PCMX).Other newer products are available, but will be discussed under the hand rub (brushless scrub) section. Povidone-Iodine has a broad spectrum of activity but it is inactivated by organic material. Additionally, it requires a minimum 2-minute contact time, which can be easily achieved using either method of surgical hand scrub patterns. Chlorhexidine also has a broad spectrum of activity and has the best residual effect due to it binding to keratin. It is not inactivated by organic material and causes less skin irritation than Povidone-Iodine (Sigler, M. 2001). Chloroxylenol is available as scrub impregnated sponges and traditionally has been outperformed by chlorhexidine.

Before a surgical scrub can begin, all jewelry must be removed from the hands and arms. Nails should be inspected and if too long, they must be trimmed. Neither nail polish nor artificial nails are permitted. Appropriate head and face attire must be put on and the surgical scrub top must be tucked into the scrub pants. If shoe covers are used, they must be placed on the footwear prior to the scrub beginning.