We’ve had a flurry of updates on guidelines for prevention of SSI’s (surgical site infections). Last year the American College of Surgeons (Ban 2016), the American College of Obstetricians and Gynecologists (Pellegrini 2016), and WHO (Allegranzi 2016a, Allegranzi 2016b) published their updated guidelines. And the Society for Healthcare Epidemiology of America (SHEA) and the Infectious Diseases Society of America (IDSA) published their update in 2014 (Anderson 2014). Now the Centers for Disease Control and Prevention has published it’s new guidelines (Berríos-Torres 2017).
The new CDC guideline focuses heavily on antimicrobial prophylaxis but includes several other salient recommendations:
It recommends that preoperative antimicrobial agents be administered only when indicated based on published clinical practice guidelines and timed such that a bactericidal concentration of the agents is established in the serum and tissues when the incision is made (that includes administration of appropriate parenteral prophylactic antimicrobial agents before skin incision in all cesarean section procedures). It recommended no further refinement of timing for preoperative antimicrobial agents based on clinical outcomes and notes this is an unresolved issue. (Note our comments below on a new study that showed no advantage of earlier vs. later administration).
Interestingly, the CDC guideline makes no recommendation regarding antibiotic dosing either with respect to patient weight or redosing during long procedures. Note that we have often stressed that these two issues should be discussed during the preoperative “huddle” (or “briefing”). The CDC guideline acknowledges that several of the other guidelines do have recommendations about these two issues and provides that information in supplemental form.
Also the guideline recommends against additional prophylactic antimicrobial doses in clean and clean-contaminated procedures after the surgical incision is closed in the operating room, even in the presence of a drain (strong recommendation with high-quality evidence).
Advise patients to shower or bathe (full body) with soap (antimicrobial or nonantimicrobial) or an antiseptic agent on at least the night before the operative day (strong recommendation; accepted practice) and perform intraoperative skin preparation with an alcohol-based antiseptic agent unless contraindicated (strong recommendation; high-quality evidence). Our comment: don’t forget the risks for surgical fires with alcohol-based antiseptics so proper precautions must be maintained at all times (see our multiple columns on surgical fires).
The CDC guideline recommends blood glucose in the perioperative period with target levels less than 200 mg/dL in patients with and without diabetes.
The CDC guideline recommends maintenance of perioperative normothermia, without endorsing a specific method to be used.
Use of supplemental oxygen has long been a controversial issue and one has to weigh any potential benefits against potential risks. But the new CDC guideline does recommend that for patients with normal pulmonary function undergoing general anesthesia with endotracheal intubation, administer increased FIO2 during surgery and after extubation in the immediate postoperative period. To optimize tissue oxygen delivery, maintain perioperative normothermia and adequate volume replacement (strong recommendation; moderate-quality evidence). Note that a meta-analysis by Yang et al. (Yang 2016) found moderate evidence to suggest that administration of high FiO2 to patients undergoing surgery, especially colorectal surgery, reduces the risk of SSI. (Our comment: again keep in mind the risk for surgical fires that a high oxygen environment brings and take appropriate precautions to minimize that risk.)
Perhaps the most striking aspect of the CDC guideline document, as pointed out in the invited commentary (Lipsett 2017), is the sheer number of practices for which there was insufficient evidence to make a recommendation. We also refer you to those other recent guidelines listed in the first paragraph of today’s column.
There have been a few other recent studies relevant to SSI’s. As noted above, a recent randomized controlled trial looked at timing of antibiotic prophylaxis (Weber 2017). Current practice calls for administration of surgical antimicrobial prophylaxis for the prevention of SSI’s within 60 minutes before incision. In this RCT the median administration time was 42 min before incision in the early group and 16 min before incision in the late group (cefuroxime was the antibiotic used in this study). Early administration of SAP did not significantly reduce the risk of SSI compared with late administration. The findings do not support any narrowing of the 60-min window for the administration of a cephalosporin with a short half-life.
The accompanying editorialist (Humphreys 2017) stresses that, though we don’t yet know the optimal timing for prophylactic antibiotics, it is “incumbent on the surgical team, anesthetic team, pharmacist and antimicrobial stewardship program to ensure the that patient receives the first dose of antibiotics during this important 1-hour window”.
Also published recently was a “Consensus Bundle on Prevention of Surgical Site Infections after Major Gynecologic Surgery” (Pellegrini 2016). This bundle was developed by a multidisciplinary team convened by the Council on Patient Safety in Women's Health Care and is organized into four domains: Readiness, Recognition and Prevention, Response, and Reporting and Systems Learning.
Under “Readiness” it stresses establishment of standards for preoperative care instructions and education for women undergoing major gynecologic surgery (such as hysterectomy), including postoperative wound care instructions, delineation of responsibility for every member of the surgical team, standards for temperature regulation (including not only patient normothermia but also ambient operating room temperature), standardization of selection and timing of administration and discontinuation of prophylactic antibiotics, ideally using order sets or checklists, and standards for appropriate skin preparation both preoperatively and postoperatively.
Under “Recognition and Prevention” it stresses assessment of patient risk preoperatively for surgical site infection using criteria that include blood glucose level, BMI, immune status, MRSA, nutritional status, and smoking status.
Under “Response” it stresses intraoperative “Timeouts” to address antibiotic dosage, timing, prophylaxis issues, and patient-specific issues and reassessment of patient risk for SSI based on length of surgery, potential bowel incision, vaginal contamination, and amount of blood loss. And, of course, it stresses postoperative care instructions and education for patients and family/support persons.
Under “Reporting and Systems Learning” we are pleased to see they stress establishment of a “culture of huddles” for high-risk patients. They also note the importance of creating a system to analyze and report surgical site infection data, monitor outcomes and process metrics, collect and share physician-specific surgical site infection data with all surgeons as part of their ongoing professional practice evaluation, and standardize a process to actively monitor and collect surgical site infection data with postdischarge follow-up.
Not included in the CDC guideline is information from a just published study demonstrating the incidence of SSI’s is highly seasonal (Anthony 2017). Basically, warmer weather increases the SSI rate and lower temperatures decrease the rate. SSI incidence is highest in August and lowest in January (rates 26.5% higher in August than January). Utilizing a large national database and average monthly temperatures based on hospital location, the found the odds of a primary SSI admission increased by roughly 2.1% per 2.8°C (5°F) increase in the average monthly temperature. The highest temperature group, >32.2°C (>90°F), was associated with an increase in the odds of an SSI admission of 28.9% compared to temperatures <4.4°C (<40°F). Note that the study did not report whether there is an association between humidity and SSI’s. Our own experience is that OR’s sometimes have difficulty maintaining their OR ambient temperature and humidity within prescribed limits during hot, humid summer months. Since we can’t control the outside temperature, these new data suggest we need to pay more careful attention to maintain OR temperature and humidity within prescribed range limits and to defer surgery in those OR rooms that are not within the range.
And, speaking about assessment for risk of SSI, there was recently published a new simple risk stratification score for SSI’s (Amri 2017). Retrospectively looking at almost 1500 patients treated surgically for colon cancer at Massachusetts General Hospital over a ten year period, they identified the following risk factors as being significant for SSI’s: smoking, alcohol abuse, type 2 diabetes, obesity, surgical durations greater than 140 minutes, and nonlaparoscopic approaches. SSI rates were:
The authors suggest that this simple risk score can be used to stratify patients by SSI risk and identify patients at risk during their postoperative admission, potentially focusing frequent monitoring and more aggressive preventive efforts on high-risk patients.
And on the Ob/Gyn side there was an abstract (Reddy 2017) at the recent ACOG annual meeting which suggested that changing gloves during cesarean section prior to abdominal wall closure may reduce the risk of wound complications in non-emergent cesarean sections. The authors report preliminary findings in their randomized controlled trial and found a significant reduction in a composite of wound complications (seroma, hematoma, wound infection, skin separation of at least 1cm, or other incisional separation or abnormality requiring a bedside procedure) in the glove-changing group compared to the control group (5.9% vs. 12.9%). The intervention is based on the theory that vaginal flora might be transferred to the abdominal area during the procedure. The intervention consisted of the entire surgical team changing gloves prior to abdominal wall closure. This was a relatively small, single-site study but the intervention is quite low-cost. So it will be interesting to see if the results can be replicated in larger multi-site studies.
Ban KA, Minei JP, Laronga C, et al, American College of Surgeons and Surgical Infection Society: Surgical Site Infection Guidelines, 2016 Update. Journal of the American College of Surgeons 2016; Published online: November 30, 2016
Pellegrini JE, Toledo P, Soper DE, et al. Consensus Bundle on Prevention of Surgical Site Infections after Major Gynecologic Surgery. Obstetrics & Gynecology 2016; Published ahead of print (Post Author Corrections): December 02, 2016
Allegranzi B, Bischoff P, de Jonge S, et al; WHO Guidelines Development Group. New WHO recommendations on preoperative measures for surgical site infection prevention: an evidence-based global perspective. Lancet Infect Dis 2016; 16(12): e276-e287
Allegranzi B, Zayed B, Bischoff P, et al; WHO Guidelines Development Group. New WHO recommendations on intraoperative and postoperative measures for surgical site infection prevention: an evidence-based global perspective. Lancet Infect Dis 2016; 16(12): e288-e303
Anderson D, Podgornny K, Berrios-Torres S, et al. Strategies to Prevent Surgical Site Infections in Acute Care Hospitals: 2014 Update. Infection Control and Hospital Epidemiology 2014; 35(6): 605-627 (June 2014) electronically published May 5, 2014
Berríos-Torres SI, Umscheid CA, Bratzler DW, et al. for the Healthcare Infection Control Practices Advisory Committee . Centers for Disease Control and Prevention Guideline for the Prevention of Surgical Site Infection, 2017. JAMA Surg 2017; Published online May 3, 2017
Yang W, Liu Y, Xhang Y, et al. Effect of intra-operative high inspired oxygen fraction on surgical site infection: a meta-analysis of randomized controlled trials. J Hosp Infection 2016; 93(4): 329-338
Lipsett PA. Surgical Site Infection Prevention—What We Know and What We Do Not Know (Invited Commentary). JAMA Surg 2017; Published online May 3, 2017
Weber WP, Mujagic E, Zwahlen M, et al.Timing of surgical antimicrobial prophylaxis: a phase 3 randomised controlled trial. The Lancet Infectious Diseases 2017; published 03 May 2017
Humphreys H. Precise timing might not be crucial: when to administer surgical antimicrobial prophylaxis. The Lancet Infectious Diseases 2017; published 03 May 2017
Amri R, Dinaux AM, Kunitake H. Risk Stratification for Surgical Site Infections in Colon Cancer. JAMA Surg 2017; Published online April 12, 2017
Reddy B, Scrafford J. Effect of Intra-operative Glove-changing During Cesarean on Post-op Complications: A Randomized Controlled Trial. Abstract 12OP. ACOG 2017
Anthony CA, Peterson RA, Polgreen LA, et al. The Seasonal Variability in Surgical Site Infections and the Association With Warmer Weather: A Population-Based Investigation. Infection Control & Hospital Epidemiology 2017; 1 DOI: 10.1017/ice.2017.84