APSIC guidelines for the prevention of surgical site infections

It is generally accepted that preoperative bathing with soap (antimicrobial or non-antimicrobial) is beneficial prior to surgery, despite the lack of study comparing preoperative bath versus no-preoperative bath on the occurrence of SSIs.

Although recommendations on preoperative bathing in relation to time of administration and the most effective protocol for perioperative bath remains an unresolved issue, it is advisable to take at least 2 baths pre-operatively [4]. Countries with high incidence of multidrug resistant organisms may want to consider the use of an antiseptic instead of plain soap as a preoperative bath. In some Asian countries where allergy to chlorhexidine (CHG) is common or CHG is not available, alternative agents such as octenidine may be used.

Oral antibiotics have been used to decrease the luminal bacterial load since the 1930s, but it does not decrease SSI. Similarly, oral or intravenous antibiotics alone showed suboptimal effects. A 2014 Cochrane review also recommended that antibiotics should be administered both orally with mechanical bowel preparation and intravenously in 1 h before surgery to reduce SSIs [5].

There are several methods to remove hair at the surgical site preoperatively. Hair removal by shaving and the night before an operation is associated with and increased risk of SSI. Shaving and/or clipping can cause microscopic cuts in the skin that later serve as foci for bacterial multiplication [6, 7].

It is well recognized that MRSA colonization is associated with worse outcomes and a higher risk for both MRSA SSI and overall SSl. The use of MRSA bundle comprising of screening, decolonization, contact precautions, and vancomycin-containing antibiotic prophylaxis was associated with decreased rates of SSI where there was high compliance with the bundle strategies [8‐10].

The objective of cleaning hands and forearms prior to surgery is to reduce the bioburden of bacteria on the skin of the surgical team. The second objective is to inhibit the growth of bacteria. Hands and forearms should undergo a surgical scrub with a surgical antiseptic. When using alcohol-based hand rub (ABHR) solutions containing 60–80% alcohol is recommended. Water quality may be compromised with the use of tap aerators where these are known to be easily colonized with non-fermentative Gram-negative bacteria e.g. Pseudomonas aeruginosa, Acinetobacter baumannii, etc. Hence, where there are issues with the quality of water used in rinsing hands after hand scrubbing, hand rubbing with ABHR agent is a suitable alternative [11‐13].

Current evidence suggested that alcohol-based preparations are more effective in reducing SSI than aqueous preparations, and should be used, unless contraindicated [14, 15]. Alcohol has a rapid bactericidal effect, albeit with the lack of persistent antibacterial effect. The benefit of iodine or chlorhexidine and alcohol solutions is prolonged bactericidal activity [16].

Current guidelines suggest the use of narrow spectrum antibiotics, such as cefazolin for most surgical procedures, or cefoxitin for abdominal surgery, as surgical antimicrobial prophylaxis. In situations where the incidence of MRSA-associated SSI is high or in case/s of penicillin allergy, vancomycin or fluoroquinolone can be used as an alternative. Current evidence supports the administration of an antimicrobial for surgical prophylaxis within 1 h before incision or before inflation of a tourniquet in orthopaedic procedures, or within 2 h for vancomycin or fluoroquinolones, because of their recommended infusion times [17, 18]. In most cases, it is recommended that a single dose of surgical antimicrobial prophylaxis is adequate.

Changes in host immunity may increase a patient’s susceptibility to SSIs and malnutrition may contribute to poor surgical outcomes, including delayed recovery, morbidity and mortality, prolonged hospital stay, increased health care costs and readmission. Meta-analysis and randomized controlled studies do not consistently show either benefit or harm when comparing standard versus enhanced nutritional support in reducing the risk of SSIs [19‐22]. Underweight patients undergoing major surgical procedures, especially oncology and cardiovascular operations, however, may benefit from enhanced nutritional support.

One of the commonest surgical complications in patients with pre-existing diabetes mellitus and hyperglycemia is infection, with superficial surgical site infections (SSIs), deep wound infections, surgical space abscesses, urinary tract infections and pneumonia accounting for a large percentage of infectious complications. The American Diabetes Association defines poorly controlled diabetes as having a target HbA1c level of ≥8% [23]. Using this threshold, studies have shown a higher occurrence of postoperative wound infections in cardiac and orthopaedic patients who had HbA1C levels of ≥8% [24, 25]. To optimize the care of the patient with diabetes and reduce the risk of complications, a team-oriented approach to treatment is highly recommended [26‐28].

Exposure of large surfaces of skin to cold temperatures in the operating room can cause hypothermia. Hypothermia results in patients waking with chills and shivering, and also raises the risk for other complications such as SSI [29‐32]. To avoid these complications, warming systems to transfer heat to a patient’s body are used. Several different methods are available, including a forced-air warming system, water bed system, and passive warming system such as blankets.

Hypovolemia and reduced cardiac output theoretically trigger musculocutaneous and splanchnic vasoconstriction, causing hypoperfusion and tissue hypoxia. Hemodynamic goal-directed therapy, a treatment based on the titration of fluid and inotropic drugs infused to physiologic flow-related end points, is shown to significantly reduce SSIs by 42% in a systematic review [33, 34].

Wound irrigation is considered to be one of the most useful SSI prevention methods by many surgeons. We agree with WHO and NICE that there is inadequate evidence to comment on this and concur with WHO that antibiotic irrigation for SSI prevention should be avoided [35, 36].

The latest meta-analysis by Leaper et al., focusing on the cost savings from SSI prevented with addition of antimicrobial sutures as a preventive measure (used in all classes of surgeries), suggests benefits [37].

In various guidelines, it is generally accepted not to recommend non-iodine- impregnated adhesive incise drapes, since it is associated with SSI risk. However, in several observational studies especially in clean surgeries, marked SSI reduction reported with the proper use of iodine-impregnated drapes [38‐42]. Considering the promising effect of controlling skin recolonization, and the fact that bacterial wound contamination may be directly linked to SSI, we believe that the use of iodine- impregnated adhesive incise drapes may be beneficial. Based on the above evidence, we do recommend their use when necessary, especially in orthopedic and cardiac surgeries.

In the WHO Global Guidelines for the prevention of SSI, the expert panel concluded that the use of a wound-protector device (single-ring or double-ring) was associated with a significantly lower risk of SSI than with conventional wound protection (OR 0·42; 95% CI 0·28–0·62). Unfortunately, the quality of evidence was too low to justify a recommendation to routinely use wound protectors. In resource limited countries, these single use devices may be financially prohibitive [10, 43‐45].

We concur with the Centers for Disease Control and Prevention (CDC), where in its latest guidelines strongly recommended not to apply antimicrobial agents (i.e. ointments, solutions, or powders) to the surgical incision for the prevention of SSI [46]. Though many studies provide supportive results, several serious concerns exist regarding their study designs, including the randomized controlled trials (RCTs) [47, 48]. With global concern on antimicrobial resistance, we will need to discourage the unnecessary resistance pressure associated with use, leading to vancomycin resistant Staphylococcus aureus (VRSA). Hence, vancomycin powder is not recommended for the purpose of preventing SSIs at this point, including spinal surgery.

Heterogeneity is seen with data published, and lack of standardization is noted in the surveillance methods and registers used regarding the use of laminar air flow and its association with SSI. In the latest meta-analysis from the WHO, with some additional studies, the risk for deep SSI in association with laminar air flow showed no significant difference compared with a conventional air flow system, with OR: 1.08(95% CI 0.77–1.52, p = 0.65) for knee arthroplasty, OR: 1.29 (95% CI 0.98–1.71, p = 0.07) for hip arthroplasty, and OR: 0.75(95% CI 0.43–1.33, p = 0.33) for abdominal and open vascular surgeries. Therefore, WHO has suggested laminar air flow is not required to reduce the risk of SSI for patients undergoing total arthroplasty surgery, and laminar air flow is not required in new operating rooms. Due to the high expense, laminar air flow is not considered necessary for installation in new operating rooms, unless supportive sufficient clinical evidence has been provided.