Surgical infections Control

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