Surgical site infections represent a significant burden to healthcare resources. In the United States alone, around 160,000 to 300,000 people undergoing surgical procedures develop surgical site infections (SSIs).1 The financial cost incurred by SSIs is also huge, with some estimates placing the loss to around $3.5 to $10 billion.2 While the incidence of surgical site infections has decreased in recent times due to advances in aseptic surgical techniques and antibiotic prophylaxis, SSIs still form a leading cause of morbidity and mortality in surgical patients.

What Are Surgical Site Infections?

According to the CDC, infections that occur 30 days postoperatively (or 90 days in case of a surgical implant) are called "surgical site infections".3 They were originally referred to as "surgical wound infections" but the term was replaced in 1992. Before the advent of laparoscopic and minimally invasive procedures, surgical procedures resulted in the creation of an external wound. Therefore, a surgical wound undergoes the same wound healing stages that a wound from any other cause would.

Wound healing and wound healing stages may be affected by the characteristics of the surgical incision, and the presence of infection. An ideal surgical wound is sterile and heals rapidly without any complications. Unfortunately, the presence of bacteria and other microorganisms at the wound site can significantly delay wound healing and lead to tissue breakdown.

Surgical site infections can be classified according to the degree of tissue involvement. The main types of SSIs include:

• Superficial Incisional SSI: affects the skin and subcutaneous tissue
• Deep Incisional SSI: affects deeper tissues, including fascia and muscles
• Organ Space SSIs: affects internal/vital organs

Risk Factors

Several intrinsic and extrinsic risk factors lead to the development of SSIs. As surgical site infections delay wound healing stages, it is important for surgeons and wound care specialists to identify and mitigate the modifiable risks, 

The following risk factors have been identified with the development of SSIs:

• Diabetes mellitus
• Obesity
• Low albumin levels (<3.5 mg/dL)
• Immunosuppression
• Increasing age
• Previous history of skin or soft tissue infection
• Malnutrition 
• Local factors: open surgery, contaminated instruments, poor skin preparation
• Smoking
• Implants
• Recent hospitalisation4

Wound Care For Surgical Site Infections (SSIs)

As the majority of surgical patients are discharged soon after the procedure, the majority of SSIs are missed by surgical teams as SSIs usually take time to develop. Thus, patients and their caregivers should be informed about proper wound care and clinical signs that signal the onset of infection. They should also be told to contact wound care specialists in case of a suspected SSI.

Following are the principles of management for surgical site infections:

• Obtain Imaging and Cultures: CT scan or MRI can be used to diagnose deep-seated infections. Ultrasound can also be used to identify the presence of fluid in subcutaneous tissues. A gram stain and culture should be obtained from the wound site in case of suspected surgical site infection (SSI). The swab should be obtained directly from the site instead of obtaining it from the surrounding skin.

• Wound Exploration and Debridement: A suspected SSI should be opened for wound exploration. Surgical sutures and staples should be removed, and wound edges should be separated to allow for the drainage of infected fluid. This also allows wound care specialists to assess the extent of infection and tissue involvement. Cultures should be obtained from the infected fluid. Irrigation of the wound should be done with normal saline.5

Moreover, debridement is recommended to remove the necrotic tissue as it aids in improving wound healing. Foreign bodies should be removed from the surgical wound site as their presence can delay wound healing. 

• Antibiotics: Antibiotics are recommended for the treatment of deep incisional SSIs and organ space SSIs. However, antibiotics should only be administered when the following clinical signs and symptoms are present:

                   - Cellulitis and erythema of surrounding skin

                   - Implants

                   - Systemic signs of infection (e.g high-grade fever)

Antibiotic therapy should be guided by the culture results of the wound specimen. The most common pathogens implicated in surgical site infections include Staph Aureus, Streptococcus and Enterococcus.6

• Wound Dressing: Moist dressing is preferred in the management of surgical wounds as it allows for retention of required growth factors for healing. Normal saline should be used to moisten the gauze, and layers of dry gauze should be placed over it. The dressing should be changed frequently, at least three times a day before the granulation tissue starts appearing. An ideal dressing should retain moisture, have microbicidal properties and should not damage the granulation tissue.7

• Negative Pressure Wound Therapy (NPWT): Negative pressure wound therapy can be used for the management of surgical wounds. They allow for fewer dressing changes and have been found to promote wound healing. However, the use of NPWT early in the course of SSI might be counterintuitive and considered controversial.

• Wound Reconstruction: Wounds with tissue loss due to debridement might require skin grafts to provide adequate coverage to the wound site. Adequate nutrition and wound care should be ensured for the best results.

Prevention of Surgical Site Infections - The Role of Telehealth

Surgical site infections (SSIs) are preventable with adequate postoperative care and monitoring. Telehealth can help wound care specialists, podiatrists and surgeons provide the continuity of care to patients after they have been discharged. It can be an excellent alternative for patients who might not be able to readily access healthcare facilities. Monitoring of chronic wounds by podiatrists and wound care specialists using telemedicine facilities has been studied with promising results. Similar studies studying the effectiveness of telehealth in diagnosing SSIs found around 69.5% to 100% accuracy.8 The use of telehealth services can help prevent complications associated with SSIs via early detection and management.

References

1. Anderson DJ, Podgorny K, Berríos-Torres SI, Bratzler DW, Dellinger EP, Greene L, Nyquist AC, Saiman L, Yokoe DS, Maragakis LL, Kaye KS. Strategies to prevent surgical site infections in acute care hospitals: 2014 update. Infection Control & Hospital Epidemiology. 2014 Sep;35(S2):S66-88.
2. Magill SS, Edwards JR, Bamberg W, Beldavs ZG, Dumyati G, Kainer MA, Lynfield R, Maloney M, McAllister-Hollod L, Nadle J, Ray SM. Multistate point-prevalence survey of health care–associated infections. New England Journal of Medicine. 2014 Mar 27;370(13):1198-208.
3. Horan TC, Andrus M, Dudeck MA. CDC/NHSN surveillance definition of health care–associated infection and criteria for specific types of infections in the acute care setting. American journal of infection control. 2008 Jun 1;36(5):309-32.
4. Neumayer L, Hosokawa P, Itani K, El-Tamer M, Henderson WG, Khuri SF. Multivariable predictors of postoperative surgical site infection after general and vascular surgery: results from the patient safety in surgery study. Journal of the American College of Surgeons. 2007 Jun 1;204(6):1178-87.
5. Fernandez RS, Griffiths R, Ussia C. Water for wound cleansing. International Journal of Evidence‐Based Healthcare. 2007 Sep;5(3):305-23.
6. Weigelt JA, Lipsky BA, Tabak YP, Derby KG, Kim M, Gupta V. Surgical site infections: causative pathogens and associated outcomes. American journal of infection control. 2010 Mar 1;38(2):112-20.
7. Sharp KA, McLaws ML. Wound dressings for surgical sites. Cochrane Database of Systematic Reviews. 2001(2).
8. Ng HJ, Huang D, Rajaratnam V. Diagnosing surgical site infections using telemedicine: A Systematic Review. The Surgeon. 2021 Jun 19.

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