Surgical site infections (SSIs) are a patient safety priority with recent initiatives introduced by the Centres for Medicaid and Medicare Services and the Joint Commission on the Accreditation of Healthcare Organisations.
SSIs are common and costly, occurring in approximately 2% to 5% of all patients undergoing gynaecological surgery. Steiner and Strand (2017) in the American Journal of Obstetrics and Gynaecology review predictive factors of SSIs and the evidence in obstetrics and gynaecology. Here we summarise their findings:
Preoperative factors altering the risk of SSI
- Bathing or showering with an antiseptic skinwash: It is good clinical practice for patients to bathe or shower prior to surgery. A recent review found no clear evidence of benefit for preoperative showering or bathing with chlorhexidine over other wash products to reduce the risk of SSIs. Either plain soap or an antimicrobial soap may be equally effective.
- Hair removal: A Cochrane review compared hair removal vs no hair removal and found no statistically significant difference in SSI rates. There was a greater risk of SSI when shaving compared to clipping hair. There was no difference between hair removal the day before surgery or on the day of surgery.
- Glycaemic control: tight glycaemic control is beneficial in reducing SSI rates in patients with and without diabetes. Patients without diabetes can still be susceptible to ‘stress hyperglycaemia’.
- Prophylactic antibiotics: preoperative antibiotic prophylaxis is the current standard of care for hysterectomies.
- Abdominal/vaginal preparation. For skin antisepsis, chlorhexidine-alcohol-based skin preparation is superior to Betadine. Decreasing bacterial counts in the vagina reduces SSI risk (chlorhexidine in concentrations of 4% or less).
- Increased operative time consistently has been shown to increase SSI. This is potentially due to temperature regulation, inflammation, and anaesthesia management.
- Maintaining normal body temperature: Evidence strongly recommends maintenance
- Wound closure: A 2014 Cochrane review found that sutures were significantly better than tissue adhesives for reducing the risk of wound dehiscence. Available data suggests there is no difference between SSI rates and braided vs monofilament suture types.
- Drain placement: The data for drain placement are mixed and mainly from obstetrics studies but appear to argue against the use of routine, prophylactic drain placement.
- Intraabdominal irrigation: Evidence suggests it is unlikely to play a role in SSI prevention.
- Subcutaneous tissue re-approximation: In a 2014 Cochrane review, rates of SSI were not improved by closure of the subcutaneous tissue. Animal studies suggest that subcutaneous sutures increase the risk of SSI. Further studies are needed.
- Supplemental intraoperative oxygen: This has benefits such as improved immune function and increased oxygen exposure to the tissue bed leading to increased collagen deposition that may lead to reduced SSI.
- Glycaemic control: both in diabetic and non-diabetic populations.
- Blood transfusion: Perioperative blood transfusions are an independent risk factor for
- Wound dressing: A postoperative dressing has been found to be unlikely to affect SSI rates, or that one is better than another.
While these factors increase the risk of SSI, many of these may not be within the surgeon’s control.
- Steroid use
- Prior surgery
Preventing SSIs: What is recommended?
Using several evidence-based strategies (bundle) is more likely to have an impact rather than pursuing any single strategy on its own.
Evidence-based strategies include:
- Administration of prophylactic antibiotics
- Chlorhexidine-alcohol based prep
- Use of monofilament suture for skin closure
- Maintenance of glycaemic control in the postoperative period
- Several studies have shown that patients undergoing laparoscopic hysterectomies experience about a 50% reduction in SSI incidence and a shorter hospital stay compared with those undergoing open abdominal hysterectomies.
Several interventions that need to be further investigated include:
- Preoperative chlorhexidine shower protocols
- Universal preoperative screening for bacterial vaginosis
- Re-approximation of the subcutaneous tissue
- The use of perioperative or postoperative hyperoxia
- The impact of preserving normothermia on SSIs. However given the harms of hypothermia this should be standard practice.