Managing Surgical Site Infections

Course Highlights

  • In this course we will learn about surgical site infections, and why it is important for all members of the healthcare team to recognize, treat, and prevent them.
  • You’ll also learn the basics of common risk factors for surgical site infections.
  • You’ll leave this course with a broader understanding of how to prevent these infections from arising in post-op patients.


Contact Hours Awarded: 1.5

Course By:
Elizabeth Walters

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The following course content

Surgical site infections have the highest mortality rate of all healthcare-associated infections, with a mortality rate of 3% (4, 9, 36). Further, surgical site infections are costly for facilities, with an estimated total cost of $3.3 billion dollars and approximately one million extra unnecessary inpatient days for patients (12, 36). It is vital to utilize evidenced-based practice strategies to reduce surgical site infections.  


In my second semester of nursing school, a patient that I took care of as a student nurse had open-heart surgery, and he was on my floor. I was the student nurse assigned to him and got to discharge him that day; everything seemed to go well. He was progressing well, and he and his family were excited he was going home. A few weeks later, I was shadowing in the ICU and was shocked to see my patient from just a few weeks before laying before me on a ventilator and with multiple IV medications. The ICU nurse worked swiftly, and I stood in awe of her ability to monitor the many machines he needed in order to survive. It was eerily quiet in the ICU, and the nurse pulled me aside to let me know that the patient was not going to make it that day and that he would probably pass sometime in the afternoon. I wondered why? What could be causing this man that I had discharged from the hospital just a few weeks ago to now be dying? During a bit of downtime, I finally got the courage to ask the nurse; she then pulled back his gown. His surgical wound was red, inflamed, and weeping with pus. It was packed with layers of gauze and had an odor to it. His surgical site became infected, and he became septic. Due to the sepsis, all his internal organs were shutting down. Despite the broadest and most advanced antibiotics, the damage was done, and this patient would not recover. I then realized how serious surgical site infections could be. The patient died later that day surrounded by his daughter and son.  

Surgical site infections (SSI) are serious and associated with significant morbidity and mortality. A patient who develops an SSI is twice as likely to die as one who does not (11). Patients with surgical site infections have a fivefold increase in the chance of being readmitted to the hospital and are 60% more likely to need ICU care than those who do not develop SSI (11). Preventing surgical site infections is imperative as the number of surgical interventions in the U.S. continues to increase (6).  

Quiz Questions

Self Quiz

Ask yourself...

  1. Have you cared for a patient with a surgical site infection? 

    Think back on your career and reflect on how many people or patients you know who have had surgical procedures?

  2. How would a surgical site infection have impacted them?  

  3. Do you recall a patient or situation like the one that I have experienced? 


SSIs are defined as an infection that happens in a part of the body where the surgery takes place. The infection must occur at or near the incision within thirty days of the initial procedure or ninety days if there is any prosthetic material implanted during the procedure (7, 19). SSIs can be caused by either endogenous (microorganisms present on the patient’s skin when the surgical incision is made) or exogenous microorganisms (those from an outside environment) (11). The most common causing microorganisms of SSI are gram-positive organisms, like Staphylococcus aureus (11). Gram negative organisms like Escherichia coli are more common causative agents in gastrointestinal tract surgeries. Exogenous sources of microorganisms include things like operating room surfaces, contaminated surgical instruments, personnel, and the air (11). 

SSIs have decreased over the last several years due to a number of evidence-based interventions that health care systems implement for prevention (8). Hospitals that have implemented evidence-based prevention programs have observed a 27% reduction in SSIs (13). Further, SSIs are costly, with each surgical site infection estimated to cost from $11,000 to $25,000 for each patient. That is a projected cost to the United States of $3.2 to $10 billion each year (11).  

Quiz Questions

Self Quiz

Ask yourself...

  1. What do you think the main costs of a surgical site infection are?  

  2. Can you think of an example of an exogenous source of microorganisms that could cause a surgical site infection?   

Risk Factors for Surgical Site Infections 

There are three main categories for risk factors for developing surgical site infections: patient factors, wound factors, and procedural variables.  

Patient Factors 

There are several modifiable and non-modifiable patient risk factors that increase a patient’s risk of developing a surgical site infection, including very young or very old age, diabetes with increased HA1C and glucose over 200 within 48 hours after surgery, tobacco use, steroid use, compromised immune system, infection or colonization at a remote body site, obesity, poor nutritional status, and length of preoperative hospitalization (11). We will review the most modifiable risk factors and some strategies to assist patients or providers with modification during this module. 

Tobacco Use 

Smoking is a modifiable risk factor for the development of SSIs. Smoking is associated with a significantly increased risk of SSI and additional complications of surgical procedures (26). It is recommended that smokers quit between four and six weeks before elective surgical procedures to reduce pulmonary issues and wound complications (23, 24, 25, 31). It is especially important for procedures that involve the creation of flaps (e.g. flap-based mastectomy reconstruction) due to the importance of tissue oxygenation and complications of wound dehiscence (16, 24, 25, 31). Smokers have higher rates of wound healing complications and SSI. The Centers for Disease Control has some excellent resources for patients to quit smoking 

Diabetes/Elevated Blood Glucose 

Elevated blood glucose levels are associated with increased risks of SSI, regardless of whether the patient has diabetes or not (11). There is evidence that elevated HA1C is associated with SSI and those diabetic patients should aim for HA1C less than 7% pre-surgery (11). Perioperative and postoperative glucose control is also very important and glucose during surgery and within 48 hours post-procedure should be maintained at less than 200 mg/dL (6).  

Remote Infections/Colonization 

It is important for patients with an active infection to complete treatment for that infection prior to elective surgery (18). For example, a patient has a scheduled knee replacement surgery and is undergoing treatment for impetigo (a skin infection) on their left arm. Ideally, they would complete the treatment for the impetigo prior to the knee replacement in order to avoid a possible SSI. It is particularly important to do this when there is going to be placement of prosthetic material during the procedure, like in the case of the knee replacement.  

There has not been a consensus on the benefit and cost-effectiveness of Staphylococcus aureus screening and decolonization for patients undergoing surgery. Some studies have found a benefit and reduced rates of SSI (32, 33, 35), and others have not found any benefit (17). Therefore, it is recommended that S. aureus screening and decolonization be tailored to clinical circumstances. Some institutions have developed protocols that involve screening and decolonization for high-risk procedures, like cardiothoracic surgery, orthopedic procedures with prosthetic material implanted, and immunocompromised patients (32, 33, 35, 36). The most common decolonization protocols include nasal application of mupirocin 2% ointment twice daily for five days, and chlorhexidine wash daily for five days.  

Quiz Questions

Self Quiz

Ask yourself...

  1. Have you ever had a surgical procedure? Do you recall being screened for Staphylococcus aureus or MRSA?  

  2. What protocol does your intuition have for pre-procedure screening for Staphylococcus aureus? 

  3. What is your institution’s protocol for intraoperative glucose management?

  4. Does your intuition have a protocol for pre-procedure smoking cessation? Or does each surgeon have their own procedure for smoking cessation for their patients? 

Wound Factors 

Wound contamination is a huge risk factor for the development of an SSI (11). The surgical team classifies wounds based on the amount of microbial contamination, and this classification can be used as one way to assess the risk of a patient developing a surgical site infection. SSIs happen in about 4% of clean wounds and 35% of grossly contaminated wounds.  

Type  Class  Description 
Clean  I  An uninfected operative wound in which no inflammation is encountered and the respiratory, ailmentary, genital, or uninfected urinary tracts are not entered. In addition, clean wounds are primarily closed and, if necessary, drained with closed drainage. Operative incisional wounds that follow nonpenetrating (blunt) trauma should be included in this category if they meet the criteria. 
Clean-Contaminated  II  Operative wounds in which the respiratory, ailmentary, genital, or uninfected urinary tracts are entered under controlled conditions and without unusual contamination. Specifically, operations involving the biliary tract, appendix, vagina, and oropharynx are included in this category, provided no evidence of infection or major break in technique is encountered. 
Contaminated  III  Open, fresh, accidental wounds. In addition, operations with major breaks in sterile technique (for example, open cardiac massage) or gross spillage from the gastrointestinal tract, and incisions in which acute, nonpurulent inflammation is encountered, including necrotic tissue without evidence of purulent drainage (for example, dry gangrene), are included in this category. 
Dirty-Infected  IV  Includes old traumatic wounds with retained devitalized tissue and those that involve existing clinical infection of perforated viscera. This definition suggests that the organisms causing the postoperative infection were present in the operative field before this operation. 

Procedural Risk Factors 

There are several risk factors related to the actual procedure that can affect the risk of an SSI. The risk factors include antimicrobial prophylaxis, surgical scrub; preoperative hair removal; the protocol and choice for skin antiseptic; operating room ventilation; surgical timing, duration, and surgical techniques (11).  

The timing of surgery for a patient can lead to an increased risk of SSI. Sometimes the timing of the surgery (e.g. when during a disease course progression to have surgery versus preplanned versus emergent) can be modifiable, and sometimes, it is not (3). Patients who are undergoing emergent surgery or emergency surgery do have higher rates of SSI; this may be due to issues related to contamination or not being able to address modifiable patient risk factors (e.g., glucose control or smoking status) prior to the surgical procedure (3). Further, if a patient is undergoing treatment for cancer with chemotherapy or radiation, there is an increased risk of SSI. If an elective surgical procedure can be delayed during cancer treatment, this does decrease the risk of SSI (3).  

Quiz Questions

Self Quiz

Ask yourself...

  1. What would be the wound classification of a procedure of emergent surgery for a patient presenting with a trauma related to a gunshot wound to the abdomen in which the large intestine was perforated?

  2. What would be the wound classification of a procedure of an arthroscopic shoulder exploration surgery where there was no traumatic wound, no purulence present, no history of prior procedure?

  3. Do you think a longer surgery increases or decreases the risk of developing an SSI? Why?  

Infection Prevention Strategies 

There are several important infection prevention strategies to reduce the risk of SSIs. The vital pieces of SSI prevention include timely administration of preoperative antibiotics, surgical techniques, and interventions to reduce potential contamination from a healthcare worker. It is imperative to bundle these interventions for a reduction in SSI (3). 

Surgical Attire and Barrier Devices 

The American College of Surgeons has clear guidance for surgical attire (5). 

  1. Surgical scrubs should not be worn for patient encounters out of the operating room (OR). 
  2. OR scrubs should not be worn outside of the hospital. If worn inside of the hospital and outside of the OR, they should be covered by a clean cover or lab coat. 
  3. Attire worn during a contaminated or dirty case should be changed before the next case, even if they are not visibly soiled. 
  4. Any OR attire that is visibly soiled should be changed as soon as possible. 
  5. During all procedures, the nose, mouth, and hair must be covered.  
  6. Head and neck jewelry should be removed or covered.  
  7. Double gloving is recommended to protect the surgeon. 
  8. Masks, caps, gowns, drapes, and shoe covers are utilized to protect healthcare personnel from exposure to blood and body fluids. 

Hand Hygiene 

General hand hygiene practices should be followed by all surgical team members. For example, anesthesiologists and certified registered nurse anesthetists should clean their hands prior to medication administration in order to reduce microbial content on the hands and then stopcocks (21). 

That healthcare personnel participating in the surgery or entering the sterile field (e.g., surgeon, scrub, or surgical assistants) must also perform surgical hand hygiene. Surgical hand hygiene consists of cleaning the hands, forearms, and under the nails with an antiseptic solution (either antiseptic soap and water or alcohol-based hand rub designed for surgical hand hygiene (15).  

False fingernails, long fingernails, hand, and wrist jewelry should be removed prior to surgical hand hygiene (15). 

Skin Antisepsis 

It is very important to reduce microbial content or load on the skin prior to the surgical procedure which is completed by skin antisepsis of the patient’s skin. Skin antisepsis must be performed prior to any surgical procedure. Ideal agents for skin antisepsis should significantly reduce the bacterial load on the skin, including a broad-spectrum antimicrobial agent, be fast-acting and continue to reduce microbial load after application or have a sustained effect (11). For clean and clean-contaminated procedures, research shows that chlorohexidine is a preferred agent (14, 27, 29). Each agent has a recommended application per the manufacturer.  

Hair Removal 

Hair removal prior to surgery should be avoided due to an increased risk of SSI. The highest risk of SSI is when surgery is performed after hair removal with a razor. Razors cause small micro-abrasions in the skin and increase the microbial load on the skin. Therefore, hair removal should not be completed with a razor. If hair removal is necessary prior to a surgical procedure, it should be done with clippers or depilatory creams with clippers as the preference due to the lowest risk of SSI (10, 20, 22). 

Antimicrobial Prophylaxis    

Antimicrobial prophylaxis is a short course of antibiotics administered just prior to a surgical procedure to reduce the antimicrobial load in the body. Antimicrobial prophylaxis must be administered prior to class one and two wounds because it assumed that for classes three and four, patients are on antibiotics. Agents are chosen based on the type of surgical procedure. Antimicrobial prophylaxis must be administered at an appropriate time in related to the surgical procedure: 30-60 minutes prior to the first incision or one to two hours for antibiotics that have a long administration time (e.g., vancomycin), should be re-dosed if it the procedure has been delayed for more than one hour after the completion of the agent, during surgery serum levels of the antibiotic must be maintained, and antibiotics should be discontinued within 24 hours of the procedure (11).  

Preoperative Showering 

It is recommended by the Centers for Disease Control and Prevention that patients reduce the microbial load on their skin by showering preoperatively with an antiseptic solution. Showering with chlorhexidine gluconate has been shown to reduce microbial load on the skin by nine times. The Association of Operating Room Nurses recommends that patients undergoing a clean procedure shower twice with chlorhexidine gluconate 4%, including the night before and the morning of the procedure (11).

Quiz Questions

Self Quiz

Ask yourself...

  1. Have you ever seen someone from the surgical team doing rounds in their OR scrubs not wearing an appropriate covering (e.g. lab coat)? What is your institution’s policy regarding OR attire? 

  2. Does your institution have a policy on hand hygiene for non-sterile OR staff? If so, what is it? For example, can circulating nurses wear jewelry or have false fingernails? 
  3. What agent does your institution recommend for skin antisepsis? What is the application procedure? 
  4. Who is responsible for antimicrobial prophylaxis where you work? 

    Is there a pre-operative time out, and is antimicrobial prophylaxis included in the time out? How do you ensure that not too much time has passed after antibiotics and pre-incision? Is this a metric that is tracked and presented to you? 

  5. What is your institutions’ procedure for ensuring patients get the appropriate education for pre-operative bathing with chlorhexidine gluconate? Does your institution use pre-impregnated chlorohexidine cloths or showering with chlorhexidine gluconate soap or a combination of both?

Surgical Environment for Prevention of Surgical Site Infections 

There are a number of important prevention strategies related to the surgical environment, including maintaining normothermia, limiting OR traffic, and the use of supplemental oxygen. 


It is highly recommended that patients undergoing surgery maintain a normal temperature during the procedure (6). Perioperative hypothermia can lead to vasoconstriction and thus reduce tissue oxygenation, which then can increase the risk for SSI (11). Ways to maintain a patient’s normal temperature include warmed blankets, warmed intravenous fluids, or forced-air warming systems (11).  

OR Traffic

It is important to limit the number of people in the OR and reduce the traffic in and out of the OR to only essential purposes. Research shows that increased traffic in the OR increases the number of airborne particles and thus microbial load in the sterile environment. This increases the risk of SSI- there is a direct relationship between traffic and SSI (2, 30, 34). 

Supplemental Oxygen 

Providing high levels of supplemental oxygen during all surgical procedures is an evolving area of research. Some studies had shown a reduction in surgical site infections when supplemental oxygen was administered to patients undergoing colorectal surgery (1). It is thought that because surgery causes a localized hypoxic state in tissues, that increasing the oxygenation to these tissues can reduce the risk of SSI. However, studies have not shown this universally. In one randomized controlled trial, patients were given 80% FiO2 via their endotracheal tube actually had higher rates of SSI than patients who had 35% FiO2 administered (28).

Quiz Questions

Self Quiz

Ask yourself...

  1. What have you seen at your institution regarding OR traffic? Is every entry into the OR necessary or vital? 

  2. Is there a formal policy regarding OR traffic? If so, what is it? 


There are many strategies to prevent surgical site infections, including from the patient side, infection prevention strategies, and the surgical environment; the most effective programs bundle all these interventions. As the number of surgical procedures is rising, it is imperative to continue to be vigilant in preventing surgical site infections.  

References + Disclaimer

  1. Al-Niaimi A, Safdar N. (2009) Supplemental perioperative oxygen for reducing surgical site infection: a meta-analysis. J Eval Clin Pract, 15:360-365. PUBMED:19335497.  
  2. Andersson AE, Bergh I, Karlsson J, et al. (2012). Traffic flow in the operating room: an explorative and descriptive study on air quality during orthopedic trauma implant surgery. Am J Infect Control 40:750. 
  3. Anderson, D. & Sexton, D. (2020). Overview of control measures for prevention of surgical site infection in adults. UpToDate. Retrieved from: 
  4. Awad, S.S. (2012) Adherence to surgical care improvement project measures and post- operative surgical site infections. Surgical Infection (Larchmt), 13(4):234-7.  
  5. Ban KA, Minei JP, Laronga C, et al. (2017). American College of Surgeons and Surgical Infection Society: Surgical Site Infection Guidelines, 2016 Update. J Am Coll Surg 224(59) 
  6. Berrios-Torres, S. et al. (2017). Centers for Disease Control and Prevention Guideline for the Prevention of Surgical Site Infection, 2017.  JAMA Surg. 152(8):784-791. doi:10.1001/jamasurg.2017.0904  
  7. Centers for Disease Control. (1992). Consensus paper on the surveillance of surgical wound infections. The Society for Hospital Epidemiology of America; The Association for Practitioners in Infection Control; The Centers for Disease Control; The Surgical Infection Society. Infection Control Hospital Epidemiolgy, 13:599. 
  8. Centers for Disease Control (2021). Healthcare associated infections. Retrieved from: 
  9. CDC National and State Healthcare-Associated Infections Progress Report, published October 2019, available from:  
  10. Cruse PJ, Foord R. (1980). The epidemiology of wound infection. A 10-year prospective study of 62,939 wounds. Surg Clin North 60(27). 
  11. Darouiche, R. (2019). Hospital infection control: Surgical site infections. Infectious Disease Advisor. Retrieved from: 
  12. de Lissovoy, G., et al. (2009). Surgical site infection: Incidence and impact on hospital utilization and treatment costs. Am J Infect Control, 37(5): 387-97.  
  13. Dellinger EP, Hausmann SM, Bratzler DW, et al. (2005). Hospitals collaborate to decrease surgical site infections. Am J Surg, 190:9. 
  14. Dumville JC, McFarlane E, Edwards P, et al. (2015). Preoperative skin antiseptics for preventing surgical wound infections after clean surgery. Cochrane Database Syst Rev :CD003949. 
  15. Fagernes M, Lingaas E. (2011). Factors interfering with the microflora on hands: a regression analysis of samples from 465 healthcare workers. J Adv Nurs 67:297. 
  16. Goltsman D, Munabi NC, Ascherman JA. (2017). The Association between smoking and plastic surgery outcomes in 40,465 Patients: An analysis of the american college of surgeons national surgical quality improvement program data sets. Plast Reconstr Surg 139:503. 
  17. Harbarth S, Fankhauser C, Schrenzel J, et al. (2008). Universal screening for methicillin-resistant Staphylococcus aureus at hospital admission and nosocomial infection in surgical patients. JAMA 299:1149. 
  18. Hennessey DB, Burke JP, Ni-Dhonochu T, et al. (2010). Preoperative hypoalbuminemia is an independent risk factor for the development of surgical site infection following gastrointestinal surgery: a multi-institutional study. Ann Surg 252:325. 
  19. Horan TC, Gaynes RP, Martone WJ, et al. CDC definitions of nosocomial surgical site infections, 1992: a modification of CDC definitions of surgical wound infections. Am J Infect Control 1992; 20:271. 
  20. Lefebvre A, Saliou P, Lucet JC, et al. (2015). Preoperative hair removal and surgical site infections: network meta-analysis of randomized controlled trials. J Hosp Infect 91:100. 
  21. Loftus RW, Muffly MK, Brown JR, et al. (2011). Hand contamination of anesthesia providers is an important risk factor for intraoperative bacterial transmission. Anesth Analg 112:98. 
  22. Mishriki SF, Law DJ, Jeffery PJ. (1990). Factors affecting the incidence of postoperative wound infection. J Hosp Infect 16:223. 
  23. Møller AM, Villebro N, Pedersen T, Tønnesen H. (2002). Effect of preoperative smoking intervention on postoperative complications: a randomised clinical trial. Lancet 359:114. 
  24. Myles PS, Iacono GA, Hunt JO, et al. (2002). Risk of respiratory complications and wound infection in patients undergoing ambulatory surgery: smokers versus nonsmokers. Anesthesiology 97:842. 
  25. Nåsell H, Adami J, Samnegård E, et al. (2010). Effect of smoking cessation intervention on results of acute fracture surgery: a randomized controlled trial. J Bone Joint Surg Am 92:1335. 
  26. Nolan MB, Martin DP, Thompson R, et al. (2017). Association between smoking status, preoperative exhaled carbon monoxide levels, and postoperative surgical site infection in patients undergoing elective surgery. JAMA Surg 152:476. 
  27. Noorani A, Rabey N, Walsh SR, Davies RJ. (2010). Systematic review and meta-analysis of preoperative antisepsis with chlorhexidine versus povidone-iodine in clean-contaminated surgery. Br J Surg 97:1614. 
  28. Pryor KO, Fahey TJ 3rd, Lien CA, Goldstein PA. (2004). Surgical site infection and the routine use of perioperative hyperoxia in a general surgical population: a randomized controlled trial. JAMA 291:79-87. PUBMED:14709579.  
  29. Privitera GP, Costa AL, Brusaferro S, et al. (2017). Skin antisepsis with chlorhexidine versus iodine for the prevention of surgical site infection: A systematic review and meta-analysis. Am J Infect Control 45:180. 
  30. Roth JA, Juchler F, Dangel M, et al. (2019). Frequent door openings during cardiac surgery are associated with increased risk for surgical site infection: A prospective observational study. Clin Infect Dis 69:290. 
  31. Sorensen LT, Karlsmark T, Gottrup F. (2003). Abstinence from smoking reduces incisional wound infection: A randomized controlled trial. Ann Surg 238:1. 
  32. Schweizer ML, Chiang HY, Septimus E, et al. (2015). Association of a bundled intervention with surgical site infections among patients undergoing cardiac, hip, or knee surgery. JAMA 313:2162. 
  33. Schweizer M, Perencevich E, McDanel J, et al. (2013). Effectiveness of a bundled intervention of decolonization and prophylaxis to decrease Gram positive surgical site infections after cardiac or orthopedic surgery: systematic review and meta-analysis. BMJ 346: f2743. 
  34. Smith EB, Raphael IJ, Maltenfort MG, et al. (2013). The effect of laminar air flow and door openings on operating room contamination. J Arthroplasty 28:1482. 
  35. Wenzel RP. (2010). Minimizing surgical-site infections. N Engl J Med 362:75. 
  36. Zimlichman, E., et al. (2013).  Health Care-Associated Infections. A Meta-analysis of Costs and Financial Impact on the US Health Care System. JAMA Intern Med, 173(22): 2039-46. 

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