SURGICAL INFECTIONS

SURGICAL INFECTIONS

• Infections that require surgical treatment or• related to operative interventions

SURGICAL INFECTIONS

• Infections required surgical treatment• • Necrotizing soft tissue infections• • Infections of body cavities (peritonitis, empyema,

etc.)• • Infections confined to an organ or tissue

(abscesses, septic arthritis, cholecystitis, etc)• • Prosthetic device infections

SURGICAL INFECTIONS

• INFECTIONS RELATED TO OPERATIVE INTERVENTION• • Wound infections - Surgical site infections• • Postoperative infections (peritonitis or other cavity infections)• • Surgical nosocomial infections (pneumonia, urinary tract infections, catheter

infections)

NOSOCOMIAL INFECTIONS

• Occurs after the initial 48 hours of admission• • Urinary tract infection• • (IV) Catheter-related infection• • Lower respiratory tract infection• • Infection via transfusion• • Bacteriemia and Sepsis

PATHOGENESIS

• DETERMINANTS OF INFECTIONS• Microorganism • Host Defenses (virulance) (type&severity of

immunosupression)• INFECTION Environment• (Fluids, foreign bodies, a closed unperfused

space etc.)

Infectious agent• The Endogenous Gastrointestinal Microflora• • Stomach• • Duodenum Aerobes and anaerobes• • Proximal small bowel <104/mL• • Distal small bowel Enterobacteriaceae

Enterococcus spp 103-108/mL Anaerobic organisms• • Colon Anaerobic organisms Bacteriodes fragilis

1012/mL

Microbiology of Intraabdominal Infections

• Aerobes:• Escerichia coli• Klebsiella spp.• Proteus spp• Enterobacter spp• Enterococcus spp• Anaerobes:• Bacteriodes spp• Peptostreptococcus spp• Clostridium spp• Bilophila wadsworthia• Fungi,Candida

HOST DEFENSE MECHANISMS

• Nonspecific• Surface Mechanical barrier• (skin, mucosa) Secretory barrier

Immunoglobulins• Ciliary motion Movement

HOST DEFENSE MECHANISMS• Specific• Cellular defense Phagocytic cells Cell-mediated

immunity (PNLs, eosinophils, mononuclear cells) (T lymphocytes & macrophages)

• Natural killer cells• Humoral defense Lyzozyme Immunoglobulins• Complement• Interferon

A Susceptible host• Causes of Impaired Host Resistance to Infection• Patient’s Underlying Condition• • AIDS• • Remote infection• • Neoplasia• • Malnutrition• • Acute stress• (burns, trauma)• • Metabolic illness• (DM, uremia)• • Aging• • Obesity• • Smoking

A Susceptible host

• Iatrogenic• • Antineoplastic• chemotherapy• • Immunosuppressive• therapy• (allograft recipients,• autoimmune disorders)• • Splenectomy

Infection Environment

• Wound or a natural space with narrow outlets

• Fluids, foreign bodies, a closed unperfused space etc

Clinical finding

• LOCAL MANIFESTATIONS OF SURGICAL INFECTIONS• • CELLULITIS: Spreading infection of the skin and

subcutaneous tissue• • LYMPHANGITIS: Inflammation of the lymphatic channels in

the subcutaneous tissue• • ABSCESS: Localized accumulation of purulent material situated in the dermis or subcutaneous tissue

SURGICAL SITE INFECTION• The term “surgical site infection” now replaces “surgical wound infection”

• • Superficial incisional SSI; involves the skin or subcutaneous tissue• • Deep incisional SSI; involves the deep tissue such as fascia or

muscle,Organ/space SSI

SURGICAL SITE INFECTIONDEFINITION

• Superficial Incisional Infection• Any incisional infection occuring within postoperative 30

days at any level above fascia described as;• • Presence of any purulant discharge (culture may not reveal

any opponent)• • Any positive culture findings from primarily closed incision• • Deleberate incision exploration• • Infection diagnosis determined by the surgeon

SURGICAL SITE INFECTIONDEFINITION

• Deep Incisional /Organ / Space Infection• Any infection occuring within postoperative 30 days or

within postoperative one year if any implant is left• described as;• • Presence of any purulant discharge (through drains)• • Any positive culture findings from intraabdominal

samples• • Spontaneous wound dehiscence• • Presence of abscess• • Infection diagnosis determined by the surgeon

Diagnosis

• • Redness• • Swelling• • Hyperthermia• • Fluctuation• • Purulent or turbid aspirate

OPERATIVE WOUNDS

• NATIONAL RESEARCH COUNCIL CLASSIFICATION OF OPERATIVE WOUNDS

CLASSIFICATION OF OPERATIVE WOUNDS

• CLEAN• • Nontraumatic• • No inflammation encountered• • No break in technique• • Respiratory, alimentary, genitourinary tracts

not entered

CLASSIFICATION OF OPERATIVE WOUNDS

• CLEAN CONTAMINATED• • Gastrointestinal or respiratory tracts entered without

significant spillage• • Appendectomy• • Oropharynx entered• • Vagina entered• • Genitourinary tract entered in absence of infected urine• • Biliary tract entered in absence of infected bile• • Minor break in technique

CLASSIFICATION OF OPERATIVE WOUNDS

• CONTAMINATED• • Major break in technique• • Gross spillage from gastrointestinal tract• • Traumatic wound, fresh• • Entrance of genitourinary or biliary tracts in

presence of infected urine or bile

CLASSIFICATION OF OPERATIVE WOUNDS

• DIRTY and INFECTED• • Acute bacterial inflammation encountered,

without pus• • Transection of clean tissue for the purpose of

surgical access to a collection of pus• • Traumatic wound with retained devitalized

tissue,foreign bodies, fecal contamination, and/or delayed treatment, or from dirty source.

Treatment• Principles of Antibiotic Therapy• • Why to use antibiotics?• • Where is infection?• • What are the most probable pathogens?• • How about antibiotic susceptibility?• • Pharmacological properties• • Is combination of antibiotics necessary?• • Host factors• • Monitoring accuracy of therapy