Surgical site infection (SSI) can be defined as an infection that occurs in a wound created by an invasive surgical procedure within 30 days from the procedure, or within 90 days if prosthetic material was implanted. This definition includes a wide range of surgical infections, from a superficial infection involving skin only to a more serious one affecting tissues under the skin, organs, or implanted material.
SSI is the second most common cause of healthcare-associated infection in Europe and the USA. Although most infections are treatable with antibiotics, SSIs remain a significant cause of morbidity and mortality after surgery. They are estimated to affect 2% to 5% of patients who undergo surgery, and. what is more important, a total of 55% of SSIs are believed to be preventable using evidence-based measures.
SSI prevention is not new. Back in the early 19th century, the Hungarian obstetrician Semmelweis was the first to focus on the importance of surgical hand washing before a procedure. He demonstrated a reduction in maternal death from puerperal sepsis through the use of chlorinated hand wash. Lister introduced the use of carbolic acid solution to sterilize surgical instruments and clean wounds. Later, in 1889, the use of surgical gloves in the operating room was introduced by Halsted.
Nevertheless, despite the great effort made in the last centuries to prevent SSIs, just a few measures have been scientifically proven. To confront this issue, guidelines have been drafted to standardize the measures and recommendations according to the best available scientific evidence and expert consensus.
In this Open Class, we will review two of the main measures to perform during the preoperative period: patient preoperative bathing and surgical hand washing, based on the latest WHO Guidelines.
This procedure consists in requiring that patients bathe or shower 24 hours before surgery, using either plain or antimicrobial soap. It ensures that the skin is as clean as possible before surgery and reduces the bacterial colonization of the skin, particularly at the site of incision. This measure is a conditional recommendation with a moderate quality of evidence.
In general, it is recommended to use an antiseptic soap (like chlorhexidine gluconate), in settings in which it is available and affordable. Nevertheless, as a meta-analysis of nine studies (seven RCTs and two observational studies) that analysed this premise showed, it has not been proved that an antiseptic soap reduces significantly the SSI incidence when compared to plain soap.
Three observational studies assessed whether preoperative bathing with chlorhexidine gluconate-impregnated cloths was more effective than using only an antiseptic soap. They showed with just very low quality evidence that using chlorhexidine gluconate cloths was associated with a decrease in SSI compared with no bathing.
Surgical hand washing
This measure consists in surgical hand preparation either by scrubbing with suitable antimicrobial soap and water or using an alcohol-based hand rub (ABHR) before wearing sterile gloves. Surgical hand washing is vitally important to ensure the least possible contamination of the surgical field. So it is a strong recommendation with moderate quality of evidence.
This preventive action is probably the one that has changed the most in recent years. Traditionally, importance has been given to use a scrub brush to friction the skin. However, this practice is currently discouraged because of the skin lesions it causes, and it is only recommended to use it to wash the nails for the first time in the day, or when they are visibly dirty. Alternatively, it is proposed to use a soapy sponge or just the friction made by rubbing hands with an ABHR. When comparing the effect of both different washing techniques, no significant differences have been found between hand rubbing and hand scrubbing in reducing SSI incidence.
Take home messages
- SSI is the second cause of healthcare-associated infection in Europe and the USA.
- 55% of SSIs are believed to be preventable using evidence-based measures.
- Preoperative bathing using soap is recommended. There is no evidence that antiseptic soap is better than plain soap.
- Surgical hand washing with an ABHR or a soapy sponge should be done before any procedure.
- The use of a scrub brush is discouraged as it causes skin lesions.