Continuing Education Activity

Postoperative wound infections are a common complication following surgery, characterized by complex and multifactorial pathophysiology. Clinicians are crucial in identifying and managing modifiable risk factors for postoperative wound infections during the perioperative phase. Comprehensive preoperative assessment and management are essential, necessitating collaboration among nursing, anesthesia, and surgical teams to identify and manage risk factors, thereby ensuring effective patient counseling. During the intraoperative phase, maintaining sterility and cleanliness in the operating room environment is crucial, as it directly influences patient recovery and infection rates intraoperatively and postoperatively. 

Incisional infections are usually noticeable, and any systemic symptoms following surgery should raise concerns about postoperative complications. However, similar symptoms may also stem from unrelated causes, such as cellulitis, allergic reactions, or urinary tract infections and pneumonia. Various factors contribute to susceptibility to infection, and diagnosis primarily relies on clinical evaluation, although wound cultures and imaging may be necessary in some instances. This activity provides detailed information on postoperative wound infections, including their etiology, epidemiology, pathophysiology, common presentations, and evaluation and treatment options. This activity also highlights the crucial role of the interprofessional healthcare team and the collaborative approach between surgical and non-surgical clinicians to ensure the best possible patient outcomes.

Objectives:

• Identify risk factors associated with postoperative wound infections during preoperative assessments.

• Implement evidence-based preventive measures to minimize the risk of postoperative wound infections.

• Apply appropriate wound care techniques to prevent and manage postoperative wound infections effectively.

• Collaborate with interprofessional healthcare teams to coordinate follow-up care and interventions, thereby optimizing patient outcomes and preventing postoperative wound infections.

Introduction

Surgical site infections represent the primary source of nosocomial infections in surgical patients.[1] Before the advent of the germ theory of infection and the recognition of the preventive efficacy of antisepsis, the incidence of postoperative surgical infections was alarmingly high, often resulting in limb amputation or mortality. However, the adoption of antiseptic techniques significantly ameliorated patient outcomes.[2][3][4][5][6][7]

Surgical site infections contribute significantly to postoperative morbidity and mortality rates, with current data revealing that they are responsible for over 2 million nosocomial infections in the United States.[8][9][10][11] The Centers for Disease Control and Prevention (CDC) classify surgical site infections into categories such as superficial, deep incisional, or organ/space infections. Any surgical wounds declared infected or opened by the surgeon are designated as surgical site infections. These infections must occur within 30 days following surgery or within 1 year after implantation to meet the classification criteria. For surgical site infection categories, please refer to the January 2023 CDC-National Healthcare Safety Network (NHSN) Patient Safety Component Manual for a more detailed description and information.

Superficial Incisional Infections 

These surgical site infections exclusively affect the skin and subcutaneous tissues, constituting over 50% of all surgical site infections. Diagnosis of a superficial incisional infection necessitates meeting one of the following criteria:

• Presence of purulent discharge from the surgical site.
• Identification of an organism from the surgical site.
• Clinical diagnosis of a surgical site infection by the surgeon.
• Deliberate opening of the wound by the surgeon, accompanied by at least one associated infectious symptom, such as swelling, erythema, or localized pain or warmth.

Deep Incisional Infections

These infections involve soft tissues deep into the subcutaneous tissue, including muscles and fascial planes. This diagnosis requires 1 of the following criteria:

• Presence of purulent discharge from the surgical site.
• Wound dehiscence.
• Deliberate re-opening of a deep incision by the surgeon due to suspicion of infection or wound spontaneously dehisces, and a positive wound culture and at least one infectious symptom is present (eg, fever, localized pain, or tenderness)
• Evidence of abscess formation or infection involving deep tissues, as observed on a computed tomography (CT) scan.

Organ/Space Infections

These infections may involve any organ or anatomical space beyond the incision site but deeper than the fascial or muscle layers, including implant-related infections. Diagnosis requires meeting one of the following criteria:

• Presence of purulent discharge from a drain placed in the organ, space, or cavity.
• Identification of an isolated organism from the involved organ, cavity, or related abscess.
• Evidence of abscess formation or infection involving the organ, cavity, or anatomical space, as observed on a CT scan.
• Notably, a wound is not considered infected if only a stitch abscess, localized cellulitis, or an infected superficial stab puncture is present.

Most surgical site wound infections originate from endogenous flora typically found on mucous membranes, skin, or hollow viscera. Generally, when the concentration of microbiological flora exceeds 10,000 microorganisms per gram of tissue, the risk of wound infection escalates.[12]

Etiology

The causes of postoperative wound infections are diverse, ranging from direct contact or airborne transmission to contamination with endogenous microbes, with susceptibility influenced by various factors. Infection patterns may vary based on the surgical procedure, operative approach, and geographical location. Risk factors can be categorized into patient and procedural factors.

Patient risk factors for wound infection include, but are not limited to, advanced age, malnutrition, hypovolemia, obesity, steroid use, poorly controlled diabetes, immunocompromised state, smoking, trauma, procedure site (intraabdominal, pelvic, or extremity), extended preoperative hospitalization, inadequate preoperative skin hygiene, and existing infections at distant sites.

Certain elective conditions can and should be optimized before surgical procedures. These factors include smoking cessation, weight loss, coagulation cascade normalization, glucose control optimization, and stabilization of other comorbidities.

Procedure-related risk factors include:

• Abnormal fluid collection such as hematoma or seroma
• Contamination of the surgical site, equipment, or personnel
• Utilization of drains
• Presence of foreign material in the surgical site
• Hypothermia
• Improper hair removal
• Inadequate antibiotic prophylaxis
• Insufficient application of the skin prep
• Short duration of surgical preoperative scrub
• Prolonged surgical time
• Poor operating room (OR) ventilation
• History of prior infection or contaminated case
• Prolonged perioperative inpatient stay
• Unsatisfactory surgical practices and techniques, including: 
  • Failure to maintain tissue hydration by periodic saline irrigation
  • Direct organ or tissue injury
  • Excessive tension when using traction or closing tissue
  • Excessive tissue trauma
  • Failure to remove dead or dying tissue
  • Inadequate hemostasis
  • Leaving excessive dead space
  • Overuse of cautery
  • Tissue devascularization
  • Unintended spillage of bowel contents
  • Unnecessary or prolonged use of drains [13][14][15][16]

Adherence to the preoperative and operative checklist is crucial in minimizing the rates of surgical site infections. The operating room team collectively bears the responsibility for adhering to best practices. Optimal ventilation is paramount, achieved through positive pressurization with adequate filtration, flow, and air exchange (ideally at least 15 exchanges per hour). Incoming air should be HEPA filtered and directly sourced from the outside, entering the operating room from the ceiling or a high position on the wall, while exhausts should be located near floor level.[17][18]

Reducing patient skin flora through a preoperative chlorhexidine shower is commonly advised the night before and/or on the day of surgery. Hair removal is recommended, preferably using clippers, immediately before surgery. However, clippers are not recommended before scrotal surgery due to the potential for excessive skin trauma. In most procedures and specialties, chlorhexidine and alcohol-based agents are typically preferred and recommended for skin preparation.

Tools and accessories, including stethoscopes, blood pressure cuffs, patient transfer slides, tourniquets, and computer keyboards, should be regularly cleaned to prevent bacterial contamination.[19][20][21][22][23] Surgical devices such as anesthesia or cautery units, suction machines, operating room lighting, and patient transfer aids can also serve as potential sources of contamination. Towels, sheets, and similar materials should be stored in closed cabinets or outside the operating room. Utilizing appropriate scrubbing techniques and double gloving can help reduce the incidence of postoperative infections.[24] The World Health Organization (WHO) surgical checklist aims to enhance communication, prevent complications, and improve safety and outcomes, including the prevention of surgical site infections. Surgical procedures are categorized as clean, clean-contaminated, contaminated, and dirty-infected, each associated with varying rates of postoperative wound infections.

The classification, according to the Canadian Agency for Drugs and Technologies in Health (CADTH) Report 2011, is defined as follows:

• Clean: A procedure characterized by the absence of inflammation and maintenance of sterility. The gastrointestinal, urogenital, and pulmonary tracts are not accessed.

• Clean-contaminated: A procedure involving entry into the gastrointestinal, urogenital, or pulmonary tracts in a controlled manner, with no existing contamination.

• Contaminated: A procedure where a breach in sterile technique occurs and/or there is gross spillage from the gastrointestinal tract, or an incision through acutely inflamed (non-purulent) tissue. This category also includes open traumatic wounds that are 12 to 24 hours old.

• Dirty or infected: A procedure performed on perforated viscera or an incision through acutely inflamed and purulent tissue. Open traumatic wounds older than 24 hours with necrotic tissue or fecal contamination also fall into this category.[25]

Epidemiology

Approximately 0.5% to 3% of all surgical patients will develop a surgical site infection.[26] However, the growing prevalence of outpatient surgery poses challenges in gathering comprehensive postoperative data. To address this, the NHSN has recently initiated protocols to collect data on surgical site infections resulting from procedures conducted in ambulatory surgical centers. Notably, surgical site infections often manifest after visits to ambulatory surgical centers or hospital discharge, documented in outpatient notes that may not be integrated into the hospital record. Therefore, any data reported by the CDC and NHSN should be interpreted within this contextual framework. 

Although the adoption of enhanced preventive measures has led to a decline in the incidence of surgical site infections over time, they still significantly impact morbidity and mortality. Surgical site infections contribute to 20% of all healthcare-associated infections.[27][28] Patients who develop surgical site infections face higher chances of requiring admission to an intensive care unit (ICU) and are associated with mortality risks ranging from 2 to 11 times greater. Additionally, they are 5 times more likely to experience hospital readmission. Surgical site infections constitute the most common cause of unplanned hospital readmissions in the postoperative period.[29][30][31][1][32]

In 2018, the reported incidence of surgical site infections in the United States was 157,500, with an estimated mortality of 8205. Within intensive care units (ICUs), 11% of all deaths were linked to surgical site infections. Patients with a surgical site infection typically require an additional 10 to 11 days of hospitalization on average and incur an extra financial burden exceeding $20,000 per admission. Consequently, the additional financial strain on the United States healthcare system approximates $3.3 billion annually.[27][33]

Surgical site infection rates are correlated with the degree of contamination of a surgical wound at the time of the surgical procedure (see Table).[34][35] 

Table. Surgical Site Infection Rates by Degree of Contamination

Pathophysiology

The inciting event in developing a surgical site infection typically begins with microbial contamination of the wound. Factors such as the virulence and quantity of the contaminating organism contribute to infection, often defined as exceeding more than 105 microorganisms per gram of tissue without a foreign body. Etiologic agents of surgical site infections can be either endogenous or exogenous. Endogenous microbes originate from the patient's skin, mucous membranes, or nearby hollow viscera or may be introduced via hematogenous spread. The most common endogenous causative organisms of surgical site infections vary depending on the procedural anatomical site. For instance, following cardiac, breast, ophthalmic, orthopedic, and vascular surgeries, Staphylococcus aureus and coagulase-negative staphylococci are frequently implicated. Conversely, following abdominopelvic procedures, Enterococcus, gram-negative bacilli, and anaerobes are more commonly encountered etiologic agents.[36]

Exogenous microbes may originate from the operating theater or its inhabitants, potentially transmitted through airborne means, on instruments or materials, or via hospital staff. Among the exogenous organisms commonly identified in surgical site infections are staphylococci and streptococci. However, the prevalence of highly virulent hospital-acquired microorganisms such as methicillin-resistant S aureus (MRSA) or extended-spectrum β-lactamase microbes isolated from surgical site infections is on the rise. This trend is likely attributed to the widespread and sometimes inappropriate use of broad-spectrum antibiotics. For instance, in a study conducted in community hospitals in the southeastern US, the incidence of MRSA-associated surgical site infections increased from 12% in 2000 to 23% in 2005. Furthermore, in the 2010 NHSN update, the proportion of surgical site infections attributed to MRSA was reported to be 43.7%.[12]

History and Physical

Symptoms of surgical site infections typically manifest within 3 to 7 days following a procedure. However, by definition, these symptoms must arise within either 30 or 90 days of the procedure, depending on the specific type of surgical procedure performed. The precise timeframe varies based on the nature of the surgical intervention.[37] 

Procedures warranting a 90-day surveillance period for the development of a surgical site infection include breast surgery, cardiac surgery, coronary artery bypass graft with both chest and donor site incisions, coronary artery bypass graft with chest incision only, craniotomy, spinal fusion, open reduction of fracture, herniorrhaphy, hip prosthesis, knee prosthesis, pacemaker surgery, peripheral vascular bypass surgery, and ventricular shunt placement.

Technically challenging, prolonged, contaminated, or emergent surgical procedures of any type carry an increased risk of surgical site infection development. Patients with superficial or deep incisional surgical site infections frequently present with a gradual onset of pain around the surgical site and general malaise or fatigue. They may or may not describe incisional discharge or frequently saturated dressings. Patients with organ/space infections may describe localized or generalized pain and systemic symptoms of fevers, chills, night sweats, fatigue, or malaise. The physical examination may reveal incisional erythema, purulent or nonpurulent discharge, wound dehiscence, or delayed healing. Tenderness with palpation may be localized or more diffuse.

The physical examination of a patient with a presumptive surgical site infection should be performed in person whenever possible. However, if an in-person examination is impossible, visualization of the affected area is imperative. A study measuring the effect of introducing wound photography for situations where face-to-face meetings are impossible demonstrated improvements in diagnostic accuracy and helped prevent overtreatment.[38]

All dressings must be removed during the physical examination, and the wound should be inspected for blisters, wound tension, edema, inappropriate tenderness, excessive erythema, fluctuance, blackish-gray tissue, and evidence of ischemia or necrosis. Palpation should be performed employing a sterile technique. Whether intentional or secondary, openings in the wound should be carefully probed with a sterile cotton swab to assess for dead space, deep closure integrity, pockets of fluid, and tissue undermining. If discharge is present, purulent or otherwise, it should be sampled and sent for culture, sensitivity, and microbiological analysis.

Evaluation

The diagnosis of a surgical site infection is predominately clinical. However, wound cultures should be performed whenever possible to isolate a potential etiologic agent and guide antibiotic therapy. Imaging with ultrasound, CT, or magnetic resonance imaging (MRI) is helpful if a deep space infection is suspected. Tools are employed to predict the likelihood of developing an infection based on risk factors. Internationally recognized traditional predictive models include the National Nosocomial Infection Surveillance System, the Australian Clinical Risk Index, and the European System for Cardiac Operative Risk Evaluation. However, the clinical value of these tools is limited by the omission of many risk factors from the calculations. Additionally, some tools have weak discriminatory abilities or do not risk-stratify for specific surgeries. Specialty- and operation-specific scoring systems are emerging, including but not limited to the two-variable Infection Risk Index in Cardiac Surgery and the Surgical Site Infection Risk Score.[39][40][41][42]

Patients with superficial incisional infections typically do not demonstrate systemic signs of infection. However, fever and leukocytosis may be present. Imaging of the affected area is of limited utility and generally not recommended. Patients with deep incisional infections are likelier to demonstrate systemic signs of infection, such as fever. Laboratory evaluation typically shows leukocytosis with a left shift, and if conducted, elevated procalcitonin and C-reactive protein levels may be observed. However, inflammatory markers are not essential for diagnosis. While diagnosing a superficial incisional infection is usually straightforward, identifying a deep incisional infection solely based on clinical grounds may pose challenges, especially in patients with obesity. Imaging the affected area with ultrasound or CT can help establish the depth, extent, and anatomical involvement. Image-guided aspiration and drainage with culture can facilitate antibiotic therapy and improve outcomes.

Patients with organ/space surgical site infections typically present with systemic signs and symptoms of inflammation and infection, though superficial incisions appear uninfected. Accurately diagnosing an organ/space surgical site infection almost always requires imaging, frequently demonstrating a fluid collection or abscess in or around the surgical site. As with deep incisional infections, image-guided aspiration is of clinical utility; when available, interventional radiology should be consulted to assess suitability for drain placement.

Patients affected by necrotizing soft tissue infections represent a distinctive subset within the surgical site infection population, posing a grave threat to life with markedly elevated morbidity and mortality rates. Typically, these patients present as critically ill within the initial 48 to 72 hours following surgery and often exhibit signs of sepsis. The physical examination usually reveals pain out of proportion to the typical postoperative course, dusky or erythematous skin, peri-incisional edema, crepitus, ecchymosis, hypovascularity, blistering, or frank tissue necrosis.[43][44][45] Incisional drainage may be present in excessive amounts. Laboratory evaluation may reveal leukocytosis or leukopenia.

Necrotizing soft tissue infections may involve any tissue, including the fascia and musculature, and spread quickly along fascial or tissue planes. Imaging studies can help confirm the diagnosis but should not delay surgical wound exploration with debridement in suspected cases.[46] Fournier gangrene is a typical example of a postoperative necrotizing soft tissue infection and is a surgical emergency.[47]

Treatment / Management

Preventive Measures

Preventive measures should be taken to mitigate postoperative infections, with a checklist approach and attention to known risk factors being paramount. The "CDC and Health Infection Control Practice Advisory Committee Guideline for the Prevention of Surgical Site Infections," a comprehensive, evidence-based guideline published in 2017, is highly recommended for this purpose. These measures can be categorized into pre-procedural, perioperative, and intraoperative phases. Key pre-procedural considerations include optimizing chronic health issues such as glucose control, medication assessment, addressing chronic wounds/infections, and smoking cessation. Perioperative steps may entail preoperative showers, hair clipping, administering operation-specific antibiotics, and appropriate skin preparation. Additionally, maintaining optimal intraoperative conditions, including temperature, air circulation, and sterility, is imperative for preventing wound infections.[29][48]

A large study from Japan demonstrated a significant reduction in surgical site infections by including a perioperative oral cleaning regimen. This included removal of tartar, plaque, and scale, professional dental cleaning, optimal denture care, including adjustments, and high-quality general dental care, including extractions as needed before surgery.[49] In a large trial, the practice of changing surgical gloves and instruments immediately before abdominal wound closure resulted in a statistically significant decrease in the rate of surgical site infections. Although preliminary, these findings suggest the need for further studies to validate this approach.[50]

The routine use of surgical drains is discouraged due to uncertainty regarding their efficacy in preventing surgical site infections, and they may impede early patient mobilization.[51][52][53] If utilized, surgical drains should be promptly removed. Various measures have been taken to reduce the incidence of surgical site infections, including antibiotic irrigation, topical antimicrobial gels, antibiotic-impregnated suture material, and antiseptic dressings, among others. However, no definitive evidence currently exists demonstrating the significant efficacy of these interventions.

Delayed primary closure, commonly utilized in cases of significant contamination, has historically been employed to mitigate surgical site infections in specific patient populations. However, a meta-analysis of randomized studies did not demonstrate any significant clinical benefit associated with this practice.[54][55] Additionally, antibiotic selection tailored to the type of surgical procedure and the prevalent microbes encountered remains crucial in preventing surgical site infections.

The utilization of prophylactic negative pressure therapy in post-surgical wounds has been proposed for specific high-risk surgical cases and contaminated wounds.[56][57] Although data generally support this practice in high-risk surgeries, outcomes vary, likely due to differences in wound contamination levels and patient and wound characteristics.[58][59] Data do not suggest that the selection of surgical dressings for closed incisions significantly affects the incidence of surgical site infections.[60] However, the use of prophylactic wound protectors, available for laparoscopy, laparotomy, and orthopedic incisions, appears to be beneficial.[61][62][63][64][65][66]

Treatment of Surgical Site Infections

Treatment decisions are influenced by factors such as the specific procedure performed, the types of microbes involved, anatomical considerations, and the patient's characteristics. In cases involving foreign bodies such as mesh, implants, stents, or metalwork, removal may be necessary due to contamination and the formation of biofilms.[67] Cultures are indicated for open wounds and drainage, especially if purulent, as the results will affect antibiotic selection. A negative wound culture might suggest an unusual infection with acid-fast bacteria or fungal organisms, particularly in immunocompromised patients. In such scenarios, specific cultures for these organisms should be obtained. 

Systemic antibiotics are required for cases with systemic signs of infection such as fever, significant skin erythema, cellulitis, or if evidence of deeper soft tissue involvement is found. In cases where patients exhibit systemic signs of infection, obtaining blood cultures should be considered. Timely interventions in patients diagnosed with sepsis have been demonstrated to be life-saving. If the infection is superficial, treatment may be limited to local wound care.[68] The primary treatment for superficial wound infections involves opening the incision, examining the wound, draining any infected fluid collections, and debriding (removing) all necrotic tissue. This procedure is typically performed at the bedside or in the office setting. If evidence suggests deeper involvement, drainage may be conducted via interventional radiology or, if needed, in the operating room. 

Once a wound has been opened, dressings must create a clean, moisture-balanced environment while ensuring tissue is appropriately debrided and maintained at an optimal temperature to facilitate healing.[69] A balanced wound matrix prevents tissue necrosis caused by desiccation and contains growth factors that support healing, epithelial regeneration, and autolysis of dead tissue. Wound dressings tailored to specific wound environments are available. The choice of dressing type and frequency of changes depend on the wound's condition and stage of healing. Topical antiseptics such as hydrogen peroxide, dilute sodium hypochlorite, and povidone-iodine solutions may be sparingly used in infected, open wounds, but their application should be limited due to the cytotoxicity they pose to the wound matrix.

In cases where mechanical debridement cannot be performed, enzymatic agents are used.[70] Cleaning and debridement should be repeated until no necrotic or devitalized material remains and healthy granulation tissue forms. Removing any infected foreign material or implants is prioritized. 

Vacuum-assisted wound therapy utilizes negative pressure to minimize dressing changes, avoid excess fluid accumulation, and promote granulation. Vacuum-assisted wound therapy has been successfully used after major trauma, orthopedic procedures, burn surgeries, and open abdominal wounds.[71] A meta-analysis revealed a statistically significant decrease in surgical site infections following spinal surgery, along with fewer postoperative complications and shorter hospitalization durations when vacuum-assisted wound therapy was employed.[72] Similarly, another meta-analysis focusing on surgical site infections in women following cesarean sections reported similar positive outcomes with the use of vacuum-assisted closure (VAC) of wounds.[73]

Wounds managed with VAC dressings may necessitate intermittent mechanical debridement. However, the use of VAC therapy requires specialized oversight, particularly when underlying organs or major blood vessels are exposed. Deep surgical site infections, especially in abdominal wounds, present unique challenges due to the risk of wound dehiscence. Consequently, exploring these wounds may be more safely conducted in the operating room. Percutaneous drainage may be considered for some cases of infected fluid collections. Notably, organ/space surgical site infections are associated with higher morbidity and mortality rates compared to other types of surgical site infections. Ultrasound and/or CT scans can facilitate the percutaneous placement of closed drains into infected fluid collections and abscesses, which may be linked to anastomotic leaks following bowel surgery. The presence of air or contrast within an intrabdominal abscess strongly suggests a bowel perforation or anastomotic leak.

Special Situations

Infections associated with the mesh, such as those occurring in hernias, typically necessitate drainage (potentially percutaneously), administration of antibiotics, wound debridement, and potential removal of the mesh. If no improvement is observed within 10 to 14 days, more aggressive intervention may be required, including surgical exploration in the operating room with likely removal of the foreign body. While a few reports indicate successful treatment with systemic and locally injected antibiotics, this approach is not considered standard of care and is generally not recommended.[74][75][76]

Management of infections involving orthopedic hardware may include bone debridement, antibiotic wound therapy, long-term antibiotics, removal of orthopedic implants and associated cement, wound irrigation, and/or surgical debridement.[77] Select patients might be successfully treated with debridement and antibiotics without hardware removal, but a therapeutic failure likely requires resection arthroplasty.[78][79] Antibiotic-impregnated cement/polymer-coated intramedullary nails have demonstrated some efficacy in preliminary studies.[80] Infected vascular grafts generally require the removal of the affected section together with an alternative vascular augmentation using an uninfected area.[81][82] Compromised overlying skin may also need to be excised.[83] Partial graft excision may be reasonable in selected patients, but meta-analyses have shown a high risk of recurrent infection and the need for reoperation.[84]

Using absorbable meshes that provide a structural matrix and can be designed to release factors that promote healing and tissue growth holds promise as an adjunct treatment for patients with impaired wound healing, particularly those with diabetes.[85] Additionally, hyperbaric oxygen therapy may be used for complex, non-healing postoperative wounds, with reported success rates of approximately 75% in such cases. See StatPearls' companion reference, "Hyperbaric Therapy for Wound Healing," for more information."[86]

Differential Diagnosis

Generally, the presence of an incisional infection is visibly apparent. Moreover, the emergence of systemic symptoms following recent surgery should consistently prompt consideration for a postoperative issue, such as infection, leakage, or ongoing bleeding. Nevertheless, it is important to recognize that other factors can cause similar symptomatology unrelated to the wound or procedure. For instance, the patient may develop cellulitis in an area unrelated to the surgical site, exhibit an allergic reaction to antibiotics or other substances, or present with an infection only loosely connected to the surgery, such as a urinary tract infection, pneumonia, or pulmonary embolus.

Prognosis

Early recognition and prompt treatment of all surgical wounds are crucial for achieving the most favorable prognosis. However, prioritizing strict adherence to a prevention protocol represents the most prudent approach. Various models have been developed across different surgical specialties to aid in identifying high-risk patients and prevent surgical site infections. For instance, a study focusing on patients with colorectal cancer identified physiological factors, tumor characteristics, and type of surgery as reliable predictive factors for the development of surgical site infection.[87] Additionally, surgical factors such as the type of procedure, emergency surgery, wound class (dirty-infected), placement of surgical drains, surgeon experience, prolonged operating time, and certain postoperative factors like extended hospital stays and the need for intraoperative transfusions were identified as independent risk factors for surgical site infections.[88]

Complications

Complications arising from surgical wound infections can manifest locally or systemically. Local complications include delayed wound healing, which can progress to chronic wounds and result in local tissue damage. Furthermore, superimposed infections, abscess formation, and osteomyelitis may also occur as additional local complications. On the other hand, systemic complications involve bacteremia, potentially leading to distant hematogenous spread and sepsis. In severe cases of infection, organ failure may develop, or existing comorbid conditions may be exacerbated.

Postoperative and Rehabilitation Care

Postoperative wound care is key to any postoperative hospital or rehabilitation stay, as the wound may be the primary reason for the patient's in-house care. Effective wound care and healing are essential for the patient's overall well-being and, in certain situations, their survival. The field of wound care is continuously evolving into a more sophisticated specialty. Providing adequate care for postoperative wounds demands timely evaluation and deliberate interventions to achieve the most favorable outcomes for patients.

Consultations

Management of postoperative wound infections may occasionally necessitate the expertise of various specialists, including infectious disease, plastic surgery, and critical care specialists.

Deterrence and Patient Education

Certain identifiable and modifiable risk factors in patients, such as body mass index, diabetic control, and smoking status, can help minimize postoperative wound infections. Elective surgeries often entail preoperative education and counseling. Before initiating certain procedures, patients may be encouraged to lose weight, adhere to a pharmacological regimen, and maintain healthy habits. 

Smoking cessation represents another crucial step in optimizing patient risk factors. Whenever feasible, involving the patient's family in these discussions is beneficial. Recommendations and protocols differ based on preexisting conditions and the proposed or necessary surgery. For instance, a spinal surgery protocol may suggest maintaining HbA1c levels below 8%, administering α-blockers for males aged 60 and older, ensuring serum albumin levels exceed 3.5 g/dL, conducting cardiac stress tests, and emphasizing smoking cessation.[89] 

Pearls and Other Issues

Antiseptic Preoperative Prep Solutions

Iodine-based sterilizing solutions, such as povidone-iodine, function by releasing free iodine, which disrupts bacterial DNA and essential intracellular proteins. These solutions possess broad antimicrobial properties and are easily accessible, cost-effective, and safe for application on all skin surfaces. They are especially beneficial for prepping transvaginal and transurethral areas as they can be safely used on mucosal surfaces. However, caution should be exercised in patients with an iodine allergy, and these solutions should not be applied to such individuals. Typically, the skin is initially scrubbed with an iodine solution and then painted with the iodine solution for application.

Alcohol-based prep solutions are known for their broad antimicrobial activity and are valued for being inexpensive, fast, and quick-acting. A single application is typically sufficient, and they dry rapidly. Compared to iodine-based antiseptic solutions, alcohol-based ones are easier to apply, have a longer-lasting antimicrobial effect, offer greater overall efficacy, require shorter drying times, and are more cost-effective. However, alcohol-based solutions are highly flammable, necessitating caution to ensure the skin surface is completely dry before proceeding. Additionally, alcohol is not suitable for application to mucous membranes.[1]

Chlorhexidine gluconate, often applied as an aqueous solution, functions by destroying the bacterial cell membrane. Notably, it boasts a longer duration of antiseptic activity compared to iodine-based antiseptics and is more resistant to neutralization. Chlorhexidine is commonly used for preoperative patient showering, surgeon hand-scrubbing, and as a skin prep agent. A large prospective study involving nearly 7,000 patients compared chlorhexidine with iodine-based antiseptic skin prep solutions and revealed no significant difference in the surgical site infection rate.[90]

Alcohol-based solutions that contain iodine or chlorhexidine combine these benefits and generally provide longer-duration antisepsis activity than single agents. Combining agents with different modes of antimicrobial activity appears to provide additive efficacy compared to single agents.[91]

When selecting surgical prophylaxis, choosing a safe, narrow-spectrum agent that covers the expected microorganisms is important. The antibiotic should be administered 30 to 60 minutes before the initial skin incision or instrumentation to ensure therapeutic levels are reached by the start of the operation.

• For clean procedures, antibiotics should cover skin flora, primarily staphylococci.

• For clean-contaminated procedures, coverage should extend to include gram-negative rods and enterococci, alongside staff staphylococci, depending on the specific procedure. Common choices include cefazolin 2 g (weight-adjusted) or vancomycin 15 mg/kg in combination with metronidazole, cefoxitin, or ertapenem.

• Antibiotic therapy should be continued for contaminated and dirty procedures based on the pre-established regimen if already initiated, or maybe adjusted intraoperatively depending on findings.*

*Note: It is often instructive to involve infectious disease and pharmacy professionals to help optimize treatment based on any culture results obtained from infected sites during the perioperative period.

Enhancing Healthcare Team Outcomes

During the perioperative period, patients interact with numerous healthcare professionals who are directly or indirectly engaged in mitigating factors associated with the risk of postoperative wound infections. Preoperatively, it is imperative to identify and address modifiable risk factors and provide the patient with appropriate counseling regarding potential risks. Although discussions about risks are primarily conducted by the nursing staff, anesthesiologists, and surgeons, the interprofessional healthcare team members must educate patients and reinforce preventive measures.

It is essential to take all reasonable measures to maintain cleanliness in the operating room, particularly around the operating table. Items such as anesthesia units, personal staff belongings like pens and cell phones, and medical equipment such as suction machines, blood pressure cuffs, Bovies, phones, intercoms, ventilation portals, and x-ray machines should be regarded as contaminated and cleaned regularly. Intraoperatively, all operating room personnel must uphold sterility and ensure an optimal surgical environment. Postoperatively, all involved clinicians influence recovery and postoperative wound infection rates.[92]