World Health Organization and the Centers for Disease Control and Prevention recommend the use of alcohol‐based solutions for surgical skin preparation [43, 44]. However, in veterinary medicine, aqueous solutions of povidone‐iodine and alcohol solutions of chlorhexidine gluconate have been proven to be equally effective in reducing bacterial colony‐forming units on canine skin [45, 46]. As many different antiseptic skin preparation solutions exist, following the instructions for your chosen product to ensure adequate contact time is key for appropriate skin preparation.
Figure 2.1(a) Mild bacterial dermatitis with pustules and plaques. (b) Mild to moderate localized dermatitis without pustules or plaques. (c) Moderate generalized dermatitis. (d) Severe generalized dermatitis over the medial aspect of the pelvic limb.
Source: All photos courtesy of Dr Charlotte Pye, DACVD.
Figure 2.2 Hanging leg technique for limb suspension. (a) A piece of 2 in. tape is applied to the lateral aspect of the unclipped distal limb, with an equal amount of tape contacting the limb and extending beyond the distal aspect of the limb. (b) Using the 2 in. tape roll, a second piece of tape is placed on the medial aspect of the unclipped distal limb, mimicking the lateral aspect. The two sticky surfaces of tape are adhered together distally, with the entire tape roll remaining attached (for later use). (c) A third piece of 2 in. tape is wrapped from proximal to distal around the circumference of the unclipped distal limb. (d) The taped distal limb is covered in nonsterile VetrapTM. (e) Using the 2 in. tape roll that remains attached to the medial aspect of the limb, the limb is suspended from an IV pole.
The initial skin preparation is carried out using nonsterile gloves and gauze. This initial preparation is performed by alternating antiseptic soap and alcohol, three times, ensuring an appropriate total contact time. A final application of an alcohol‐based antiseptic paint may also be performed. Protection of the prepared surgical site with sterile drapes is recommended prior to transport to the operating room (OR), to decrease the risk of inadvertent contamination.
A final sterile skin preparation is subsequently performed in the OR using sterile gloves and sterile gauze. This final preparation may be performed by a nonsterile assistant wearing sterile gloves or by a sterile assistant or surgeon. The final skin preparation is performed by alternating between the antiseptic solution (Figure 2.4) and alcohol, performed three times, or using an alcohol‐based antiseptic paint alone. Whichever antiseptic soap is used for the initial skin preparation must be the same antiseptic solution used in the final skin preparation.
Figure 2.3 Skin preparation steps. Note the assistant is wearing nonsterile gloves for the initial skin preparation. (a) Using a nonmedicated neutral soap, the skin is cleansed to remove oils and debris. (b) The soap suds are removed using dry nonsterile gauze squares, working from the proposed surgical site outwards. (c) Using a chlorhexidine scrub brush (or antiseptic soap of choice on nonsterile gauze), the skin is scrubbed, working from the proposed surgical site outwards. (d) The soap suds are removed using nonsterile, alcohol‐soaked gauze squares working from the proposed surgical site outwards. Steps (c) ad (d) are repeated three times, until all soap suds are removed. (e) Finally, an alcohol‐based chlorhexidine paint is applied to the skin using nonsterile gauze squares, working from the proposed surgical site outwards until the entire field has been painted*. (f) A sterile drape is applied over the field prior to transport into the OR. Steps (c)(using an aqueous or alcohol‐based antiseptic solution in place of an antiseptic soap) and (d) (or alternatively step (e) alone) are repeated in the OR using sterile gauze and sterile gloves for the final skin preparation. *Note step (e) is optional during the initial skin preparation.
2.3 Environmental Factors
2.3.1 Sources of Contamination
The perisurgical environment, including the anesthesia prep area, patient transportation, the OR, the radiology suite and surrounding personnel, plays a role as a source of possible bacterial contamination. Bacteria most commonly identified in surgical sites at the time of closure during orthopedic surgeries arise from aersol transmission [47]. One study identified 81% of elective orthopedic procedures as experiencing some form of bacterial contamination [47]. Possible sources identified included surgeon hands, surgeon gloves, animal skin, patient footwrap, sink faucet, transportation gurney, radiology table, and OR computers [47]. Despite this high number of reported contamination events and numerous sources identified, a correlation with SSI could not be made [47]. Historically, scalpel blades have been suspected to be a source of increased bacterial contamination into deeper tissues when the same blade is used for skin incisions and deeper tissue incision; this remains unclear at this time, as conflicting data exist [48–50]. However, with documented potential for bacterial transmission from the skin blade, use of a second surgical blade for deeper tissues is advised. Suction tips have also been identified as sources of contamination in clean surgical procedures. In one study, a positive culture rate of 92% was identified at the end of clean surgical procedures, with a second study identifying a 42% positive culture rate at the end of clean orthopedic procedures [51, 52]. While these sources of contamination cannot necessarily be avoided, hospital surveillance of these known sources of contamination is recommended.
Figure 2.4 (a) Chlorhexidine gluconate 4% soap solution. (b) Povidone‐iodine 10% solution, with 1% free iodine.
2.3.2 Personnel
As the majority of bacteria identified in contamination of surgical sites with and without SSIs arise from the microbiome of humans and animals within the OR, it is no surprise that an increasing number of OR personnel has been correlated with an increased SSI rate [2]. Reducing traffic in and out of the OR during clean orthopedic procedures may therefore reduce the amount of aerosolized bacterial contaminants and decrease contamination rates [53]. In academic settings, traffic in and out of the OR can anecdotally be higher, therefore in animals with inherent risk factors for SSI, attempts to reduce traffic in the OR are recommended. Both MRSA and MRSP have been identified in small animal hospital environments and among small animal employees [54]. It is possible that hospital personnel carrying MRSA and MRSP may cause direct or indirect transmission to animals [54].
2.4 Surgical Procedure
2.4.1 Surgeon Factors – Hand Hygiene, Glove Perforation, Surgical Technique
Surgeon
