SURGICAL INFECTIONS
By Dr. Ahmed Mustafa
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
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