Intervention

Details

Theories on how the intervention type might work

Intra‐operative intervention types

Decontamination of patients' skin at site of surgery incision
(for the patient)

Before surgery, patients' skin is disinfected using antiseptic solutions such as povidine‐iodine or chlorhexidine at varying concentrations.

The aim of preoperative skin antisepsis is to reduce the risk of SSIs by reducing the number of microorganisms on the skin (ACORN 2012; Mangram 1999).

Skin sealants
(for the patient)

Microbial sealants are liquids that are applied to the patient's skin before surgery and left to dry forming a protective film over the planned incision site. Cyanoacrylate, which is also used as a tissue adhesive, can be used as a skin sealant.

As with other barrier methods, the use of skin sealants is focused on preventing contamination of the surgical wound with micro‐organisms from the patient's skin. It is proposed that skin sealant use before surgery prevents any remaining micro‐organisms from migrating into the surgical wound following skin decontamination (Singer 2008).

Incise drapes
(for the patient)

Before a surgical incision is made, sterile plastic adhesive (incise) drapes can be placed onto cleansed skin. The surgical incision is then made through the drape. Drapes can be plain or impregnated with antimicrobial products.

Drapes are used as a barrier between the incision and the patient's skin, which although cleansed, may harbour micro‐organisms, such as at deeper levels of the skin that cleansing cannot reach (Swenson 2008).

Use of masks, hair covers, overshoes, gowns and other protective coverings for theatre staff
(for staff)

Protective coverings worn in theatre by staff to limit the movement of micro‐organisms in theatre (Cooper 2003).

For example: masks over the face; disposable shoe covers worn over standard footwear and changed as required; disposable or re‐usable gowns worn over standard scrub outfits and changed as required.

There are various coverings used in surgery that are designed to act as a barrier between the environment and the patient's wound to maintain a sterile operative field, such as masks that aim to capture water droplets being expelled. Masks contain one or two very finely woven filters that can inhibit bacteria. Masks cover the nose and mouth, but there is concern that masks may be worn incorrectly and allow air leaks from the sides of the mask.

Shoe coverings aim to limit the transfer of external material in and out of theatres.

Gowns cover standard surgical attire and can be removed when contaminated and replaced.

Different glove protocols
(for staff)

Surgical staff wear disposable gloves during surgery. Gloves are used in a number of ways intended to minimise microbial contamination from staff to patients, including double gloving (using two pairs of gloves), the use of glove liners or cloth outer gloves (Kovavisarach 2002; Laine 2004).

Gloves are a barrier intervention that aim to prevent transfer of micro‐organisms from the staff member's skin to the patient's skin or wound. Gloves also act as a barrier to prevent staff from infection by patients.

Use of electrosurgery for surgical incisions
(for the patient)

In electrosurgery, an electric current is used to generate heat which vaporises cellular material, cutting the skin in place of a scalpel. This can be used to cut skin from the top surface down or used on deep skin layers once an incision has been made with a scalpel (Soderstrom 2003).

It has been suggested that using heat to make a surgical incision may reduce the risk of SSI.

Maintaining patient homoeostasis (warming)
(for the patient)

During surgery the patient's bodily functions need to be optimised to promote recovery; it is further postulated this may also reduce the risk of SSI. Under general anaesthetic it is harder for the body to regulate its own temperature and this can increase the risk of peri‐operative hypothermia. Warming can be achieved using thermal insulation such as blankets, or active methods of warming that use machines to transfer heat to the patient, and use of heated intravenous fluids (NICE 2016; Whitney 2015).

Undertaking warming aims to maintain body temperature and prevent the development of peri‐operative hypothermia which can lead to negative postoperative outcomes, which potentially include SSI. These interventions can also be used postoperatively to mitigate the impact of peri‐operative hypothermia when it has not been prevented.

Maintaining patient homoeostasis (oxygenation)
(for the patient)

During surgery under general anaesthetic patients are intubated and supplied with oxygen to maintain adequate oxygen perfusion to all tissues.

It is suggested that the risk of SSI is higher when tissue oxygenation is not optimised during surgery. Some surgical protocols use higher saturation levels of oxygen during intubation to increase tissue oxygenation levels with the aim of reducing wound complications such as SSI. High oxygen levels have been linked to serious adverse events such as blindness and death (Al‐Niaimi 2009).

Maintaining patient homoeostasis (blood glucose control)
(for the patient)

Use of strict glycaemic control using medications to maintain glucose levels during surgery.

Hyperglycaemia after surgery is postulated to lead to increased risk of surgical complications including infection (Ljungqvist 2005; Stephan 2002).

Wound irrigation and intracavity lavage (including use of intra‐operative topical antiseptics before wound closure)
(for the patient)

Surgical irrigation and intracavity lavage use fluids to wash out the surgical cavity at the end of the surgical procedure before the wound is closed. Both wound irrigation and intracavity lavage can be altered by: volume of irrigation fluid; mechanism or timing of delivery; or solution composition (Barnes 2014).

The theoretical advantage of surgical wound irrigation is to reduce the bacterial load in a surgical wound, and thus the risk of SSI, through a combination of water pressure, dilution, or the application of antimicrobial agents.

Closure methods
(for the patient)

Surgical wounds can be closed using sutures (absorbable or not) staples, adhesive strips or tissue adhesives. Some closure methods can make use of sutures that are coated in antimicrobial products.

The timing of closure can also vary; some wounds can be left open for a period following surgery and then closed (delayed closure).

There is a view that the method of surgical wound closure may impact on SSI risk. There is limited background evidence on mechanisms for SSI prevention, although it has been suggested that the better the seal the closure method obtains, the better the barrier to microbial contamination (Gurusamy 2014).

Theatre cleansing
(for the environment)

The theatre environment needs to be cleaned regularly with detergents to disinfect surfaces. Daily deep cleaning is likely to occur using various protocols for cleaning surfaces between patient surgeries, especially areas that are contaminated with bodily fluid, or that are frequently touched by staff. Recent technologies used for theatre cleansing include UVC light decontamination and hydrogen peroxide vapour treatment.

Surgical instruments are also sterilised to decontaminate them after use. Various protocols are used including steam sterilisation and chemical sterilisation, which is used when steam sterilisation is not feasible.

Theatre cleaning can also involve the use of ventilation systems, such as laminar airflow systems, which supply filtered air into the environment to limit numbers of airborne micro‐organisms.

To avoid cross‐infection, special protocols may be developed for cleansing when surgical patients are known to have specific infections.

All aspects of theatre cleansing aim to minimise numbers of micro‐organisms present in the theatre environment with the aim of reducing the risk of SSI. (Spagnolo 2013).

Theatre traffic
(for the environment)

A surgical theatre can be a busy working environment with people moving in and out. This movement can be managed, for example limiting the entrance and exit of staff during surgery, and minimising visitors into the theatre (e.g. partners of women undergoing caesarean sections) (Spagnolo 2013).

A key aim in the prevention of SSI is to limit numbers of micro‐organisms in the operative environment. People moving in and out of the operative field may increase the risk of contamination. Visitors to the theatre who have not undergone full hand scrubbing protocols and so forth could also potentially increase SSI risk.

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