Surgical Site Infections Flashcards
What is a wound?
A wound is a disruption of the normal structure and function of the skin and soft tissue architecture. An acute wound demonstrates normal physiology, and healing is anticipated to progress through the expected stages of wound healing, whereas a chronic wound is broadly defined as one that is physiologically impaired
What is a surgical site infection (SSI)?
SSI is an infection related to a surgical procedure that occurs near the surgical site within 30 days following surgery (or up to 90 days (upto a year) following surgery where an implant is involved)
What are the problems associated with surgical site infections
- Problems for the patient:
- Increased pain, discomfort, and length of hospital stay
- Risk of further complications, such as sepsis or organ dysfunction
- Delayed wound healing and recovery
- Increased risk of mortality
- Problems for healthcare workers:
- Increased workload and time spent managing the infection
- Risk of exposure and potential transmission to other patients
- Decreased patient satisfaction and trust in the healthcare system
- Problems for the economy:
- Increased healthcare costs due to extended hospital stays, additional treatments, and potential readmissions
- Productivity losses for the patient and their caretakers
- Strain on the healthcare system and resources
Surgical wound classification
Class I/Clean
An uninfected operative wound in which no inflammation is encountered and the respiratory, alimentary, genital, or uninfected urinary tract is 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.
Class II/Clean-Contaminated
An operative wound in which the respiratory, alimentary, genital, or 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.
Class III/Contaminated
Open, fresh, accidental wounds. In addition, operations with major breaks in sterile technique (eg, open cardiac massage) or gross spillage from the gastrointestinal tract, and incisions in which acute, nonpurulent inflammation is encountered are included in this category.
Class IV/Dirty-Infected
Old traumatic wounds with retained devitalized tissue and those that involve existing clinical infection or perforated viscera. This definition suggests that the organisms causing postoperative infection were present in the operative field before the operation.
Class I/Clean Wounds
Risk of infection: 1-2%
An uninfected operative wound in which no inflammation is encountered and the respiratory, alimentary, genital, or uninfected urinary tract is 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.
Class II/Clean-Contaminated
Risk of infection 5-8%
An operative wound in which the respiratory, alimentary, genital, or urinary tracts are entered under controlled conditions and without spillage. 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
Class III/Contaminated
Risk of contamination 15-20%
-Open, fresh, accidental wounds.
In addition, operations with major breaks in sterile technique (eg, open cardiac massage) or gross spillage from the gastrointestinal tract (all colonic operations) and incisions in which acute non-purulent inflammation is encountered
Class IV/Dirty-Infected
Old traumatic wounds with retained devitalized tissue and those that involve existing clinical infection or perforated viscera. This definition suggests that the organisms causing postoperative infection were present in the operative field before the operation.
Empyema thoracis
Pritonitis
Ruptured abscess
Superficial Surgical Infection
Extent of tissue involvement:
=>Skin and subcutaneous tissue
Clinical features:
=>Peri-incisional pain or tenderness
=>Localized peri-incisional swelling
=>Peri-incisional erythema or heat
Criteria for diagnosis:
At least one clinical feature AND at least one of the following:
Purulent drainage from the superficial incision
Organisms are identified by culture (or non-culture-based microbiologic testing method) performed for clinical diagnosis or treatment (eg, not surveillance)
Incision opened by the surgeon (or other designated clinician) because of concern for superficial SSI
Deep Surgical Infection
Extent of tissue involvement:
=> Deep soft tissues of the incision such as the fascia and muscle layers
Clinical features:
=>Fever (>38°C)
=>Localized pain or tenderness
Criteria for diagnosis:
=>Purulent drainage from the deep incision
=>Deep incision that spontaneously dehisces or is opened by the surgeon (or other designated clinician) because of concern for deep SSI AND organisms are identified by culture (or non-culture-based microbiologic testing method) performed for clinical diagnosis or treatment (eg, not surveillance). Presence of at least one clinical feature, in absence of microbiologic testing
Organ or Space
Extent of tissue involvement:
=>Any part of the body deeper than the fascia/muscle layers that was opened or manipulated during the procedure
Clinical features:
=>Clinical features for specific organ/space can be found at the CDC website§
As an example, for intra-abdominal infection, at least two of the following:
Fever (>38°C)
Hypotension
Nausea, vomiting
Abdominal pain or tenderness
Elevated transaminases
Jaundice
Criteria for diagnosis:
=>Appropriate clinical features specific to the organ/space AND at least one of the following:
Purulent drainage from a drain placed into the organ/space¥
Organisms identified from culture of fluid or tissue obtained from a superficial incision‡
Abscess or other evidence of infection involving the organ/space detected on gross anatomical examination or histopathologic examination
Radiographic imaging findings suggestive of infection
Contaminated wound?
Colonised wound?
Infected wound?
- Contaminated Wound:
- This is the initial stage where the wound has been exposed to a significant amount of foreign material, such as dirt, debris, or microorganisms, from the environment.
- Contaminated wounds are at a higher risk of developing an infection, as the foreign material can introduce a large number of microorganisms into the wound.
- Contaminated wounds require thorough cleaning and debridement to remove the foreign material and reduce the risk of infection.
- Colonised Wound:
- This is a stage where the wound has been invaded by microorganisms, such as bacteria or fungi, but these microorganisms have not caused any damage or signs of infection.
- In a colonised wound, the microorganisms are present on the surface of the wound or within the superficial layers, but they are not causing any clinical signs of infection.
- Colonisation is a normal and common occurrence in wounds, and as long as the body’s immune system is able to control the microorganisms, the wound is considered colonised but not infected.
- Infected Wound:
- This is the most severe stage, where the microorganisms have penetrated deeper into the wound, causing damage to the tissue and triggering an inflammatory response.
- Infected wounds typically exhibit signs of infection, such as increased redness, swelling, heat, pain, purulent discharge, and potentially systemic signs like fever.
- Infected wounds require appropriate treatment, such as antimicrobial therapy and potentially debridement, to control the infection and promote healing.
Cardinal signs of inflammation
“Quintus Tumor,”
The cardinal symptoms of inflammation
- Rubor (Redness)
- Redness of the affected area, which is caused by increased blood flow and dilation of the blood vessels.
- Calor (Heat)
- Increased temperature of the affected area, which is also a result of increased blood flow and metabolic activity at the site of inflammation.
- Tumor (Swelling)
- Swelling or edema in the affected area, caused by increased fluid accumulation and the infiltration of inflammatory cells.
- Dolor (Pain)
- Pain or discomfort experienced in the affected area, which can be caused by the release of inflammatory mediators and the stimulation of pain receptors.
- Functio laesa (Impaired function)
- Impaired or decreased function of the affected area, which can be a result of the other cardinal symptoms of inflammation, such as swelling, redness, and pain.
These five cardinal symptoms of inflammation, known as the “Quintus Tumor,” were first described by the Roman physician Celsus in the 1st century AD. They are a classic representation of the body’s response to injury, infection, or other forms of tissue damage, and they serve as important indicators for the presence and severity of inflammation.
What are the different ways to prevent surgical site infections
Key preventive strategies divided into preoperative, intraoperative, and postoperative considerations, taking into account patient, surgeon, and environmental factors:
Preoperative:
Patient Factors:
- Identify and optimize modifiable risk factors (e.g., smoking cessation for at least 8 weeks priorto operatio) , glycemic control in diabetics, nutritional status and malignancy)
- Screen for and treat pre-existing infections (e.g., nasal Staphylococcus aureus carriage)
- Administer appropriate (broad spectrum) antimicrobial prophylaxis
Surgeon Factors:
- Ensure proper hand hygiene and use of surgical attire (e.g., caps, masks, gowns, gloves)
- Maintain optimal skin preparation techniques (e.g., Wash the patient with running water and put clean linen, hair removal, antiseptic agents)
Environmental Factors:
- Ensure appropriate facility design and maintenance (e.g., air filtration, temperature, humidity control)
- Implement effective sterilization and disinfection protocols for instruments and equipment
Intraoperative:
Patient Factors:
- Maintain normothermia and optimize tissue oxygenation
- Ensure appropriate antimicrobial prophylaxis dosing and timing
Surgeon Factors:
- Adhere to aseptic technique and sterile surgical field
- Minimize tissue trauma and foreign material (e.g., sutures, drains) in the wound
- Use appropriate surgical techniques to optimize wound healing
Environmental Factors:
- Maintain appropriate air quality and traffic control in the operating room
- Ensure proper sterilization and handling of instruments and supplies
Postoperative:
Patient Factors:
- Monitor for signs of surgical site infection (e.g., fever, wound erythema, drainage)
- Promote wound healing (e.g., appropriate dressings, mobilization)
- Manage any detected infections promptly with antimicrobial therapy and/or surgical intervention
Surgeon Factors:
- Provide clear wound care instructions to the patient and caregivers
- Regularly assess the surgical site and promptly address any complications
Environmental Factors:
- Maintain appropriate wound care and dressing techniques
- Ensure proper disposal of contaminated materials
By addressing these multifaceted factors throughout the perioperative period, healthcare providers can implement a comprehensive strategy to prevent surgical site infections and optimize patient outcomes.
What are the different ways to prevent surgical site infections
Key preventive strategies divided into preoperative, intraoperative, and postoperative considerations, taking into account patient, surgeon, and environmental factors:
Preoperative:
Patient Factors:
- Identify and optimize modifiable risk factors (e.g., smoking cessation for at least 8 weeks priorto operatio) , glycemic control in diabetics, nutritional status and malignancy)
- Screen for and treat pre-existing infections (e.g., nasal Staphylococcus aureus carriage)
- Administer appropriate (broad spectrum) antimicrobial prophylaxis
Surgeon Factors:
- Ensure proper hand hygiene and use of surgical attire (e.g., caps, masks, gowns, gloves)
- Maintain optimal skin preparation techniques (e.g., Wash the patient with running water and put clean linen, hair removal, antiseptic agents)
Environmental Factors:
- Ensure appropriate facility design and maintenance (e.g., air filtration, temperature, humidity control)
- Implement effective sterilization and disinfection protocols for instruments and equipment
Intraoperative:
Patient Factors:
- Maintain normothermia and optimize tissue oxygenation
- Ensure appropriate antimicrobial prophylaxis dosing and timing
Surgeon Factors:
- Adhere to aseptic technique and sterile surgical field
- Minimize tissue trauma and foreign material (e.g., sutures, drains) in the wound
- Use appropriate surgical techniques to optimize wound healing
Environmental Factors:
- Maintain appropriate air quality and traffic control in the operating room
- Ensure proper sterilization and handling of instruments and supplies
Postoperative:
Patient Factors:
- Monitor for signs of surgical site infection (e.g., fever, wound erythema, drainage)
- Promote wound healing (e.g., appropriate dressings, mobilization)
- Manage any detected infections promptly with antimicrobial therapy and/or surgical intervention
Surgeon Factors:
- Provide clear wound care instructions to the patient and caregivers
- Regularly assess the surgical site and promptly address any complications
Environmental Factors:
- Maintain appropriate wound care and dressing techniques
- Ensure proper disposal of contaminated materials
By addressing these multifaceted factors throughout the perioperative period, healthcare providers can implement a comprehensive strategy to prevent surgical site infections and optimize patient outcomes.
