Surgical Site Infections

Ignaz Semmelweis 1847 Realized that washing hand with a chlorinated lime solution decreased incidence of newborn death from “puerperal fever’.

Joseph Lister 1883-1897 British surgeon Used Carbolic Acid (Phenol) to clean hands, instruments and wipe on surgical wounds drastically decreased infections.

Outline : Important Terms Antiseptics Surgical wounds Post-operative Infections Surgical Site Infection Hospital Acquired Infections Antibiotic Prophylaxis

Definition : Colonization Bacteria present in a wound with no signs or symptoms of systemic inflammation Usually less than 105 CFU/mL

Contamination Transient exposure of a wound to bacteria Varying concentrations of bacteria possible Time of exposure suggested to be < 6 hours

DECONTAMINATION: is the process of removing or neutralizing infectious or injurious m.o. from inanimate objects CLEANING: physically removes ALL visible blood, body fluid, or other foreign material as dust or soil from skin or intimate objects.

ASEPSIS/ASEPTIC TECH.: is the practices performed just before or during clinical or surgical procedure to reduce the risk of infection that produce a state of asepsis . ANTISEPSIS: is the prevention of infection by killing or inhibiting the growth of m.o. on skin or body tissues.

DISINFECTION: is the elimination of most (but not all) disease causing m.o. from inanimate objects . High level disinfection –by boiling or chemicals- eliminate ALL m.o. except some bacterial endospores.

STERILIZATION: is the process that remove ALL m.o. including bacterial endospores form inanimate objects

antiseptics Antiseptics: Kill m.o. on skin Not strong enough to use on instruments For surgical scrubs; preparations of pt. skin or mm before clinical procedures DO NOT use for processing or storage of instruments Disinfectants: Kill m.o. on surfaces (counters; exam tables; floors…etc.) DO NOT use on skin , may irritate skin Acceptable antiseptics: As ( Alcohol; Chlorhexidine; Iodine preparations; Iodophor; Triclosan)

Alcohol (60%-90% ethyl or isopropyl alcohol) Advantage: Rapidly kill ALL fungi ; G+ve; G-ve; mycobacteria; Viruses (HBV,HIV) à ethyl alcohol kill ALL viruses Retard regrowth of organisms even under gloves for several hours Are relatively inexpensive

evaporate rapidly and cause skin dryness Disadvantage: evaporate rapidly and cause skin dryness Not appropriate for vaginal preparation Can be inactivated by organic materials Flammable Do not penetrate organic material None action on endospores Not for use on mm ; not good for physical cleaning of skin

Chlorhexidine (2%-4%) (Hibitane; Hibiscrub) 4% is the recommended concentration of chlorhexidine gluconate (CHG) Either as pure CHG or 0.5% CHG in 60%-90% alcohol Advantage: Has persistent action on skin; stays chemically active for at least 6 hours Repeated use increase the no. of inhibited mo Minimally affected by organic material

None action against endospores; fair action on fungi and TB Disadvantage: Expensive , and not always present Action reduced or neutralized by natural soap or hard tap water Must be used repeatedly for maximum effective and residual activity Can cause dermatitis when used frequently for hand washing Aqueous preparation is prone to contamination None action against endospores; fair action on fungi and TB

Iodine and iodophor solutions 2 types: 1-3% aqueous solution à Lugol 70% alcoholic tincture Iodophor are solutions of iodine mixed with carrier that release small amount of iodine The most common iodophor is Betadine Iodophor require up to 2 min. of contact time to release free iodine

Advantage: Inexpensive; effective and commonly available Iodophor are non-irritating to skin and mm making them ideal for vaginal preparation before IUD insertion Does not stain skin at 1:2500 concentration

Disadvantage: Little residual effect (30-60 minutes) Inactivated by organic materials Iodine à skin irritation ( need alcohol for removing it) . May cause hypothyroidisms in neonates due to skin absorption Iodine not iodophor is the only antiseptic effective against endospores

Surgical Wound Classification Clean Clean contaminated Contaminated Dirty

Class I Wound (Clean) Atraumatic wound without inflammation Do not enter GI, GU, biliary, or respiratory tract 1.5% infection rate Class I wounds are the simple surgeries without violation of the hollow visceral structures in a non inflamed, atraumatic wound. These wounds rarely become infected. One example would be an inguinal hernia repair.

Class II Wound (Clean-Contaminated) Respiratory, GI, GU, or biliary tract entered under controlled conditions 5% infection rate expected Class II wounds involve controlled entry into a hollow visceral structure. Examples would be cholecystectomy and elective colon resections. A higher incidence of infection is expected.

Class III Wounds (Contaminated) Traumatic wounds Breaks in sterile technique Gross spillage from GI tract Acute, nonpurulent inflammation 10% anticipated infection rate Class III wounds include major breaks in sterile technique, trauma, gross spillage of GI contents and acute nonpurulent inflammation, such as from a nonperforated acute appendicitis.

Class IV Wounds (Dirty) Old traumatic wounds Devitalized tissue Clinical infection present Perforated viscus 40% expected infection rate Class IV wounds involve older trauma, devitalized tissues, infection present at time of the operation or perforated hollow viscus. Thus, perforated acute appendicitis has a much higher wound complication rate than nonperforated.

SSI – Wound Classification Class 1 = Clean Class 2 = Clean contaminated Class 3 = Contaminated Class 4 = Dirty infected Prophylactic antibiotics indicated Therapeutic antibiotics Surgical site infections are categorized into four classes depending on wound type. Class 1 is a clean wound, class 2 is a clean contaminated wound, class 3 is a contaminated wound, and class 4 is a dirty infected wound. Mangram AJ et al. Infect Control Hosp Epidemiol. 1999;20:250-278.

Infection Infection is defined by: Microorganisms in host tissue or the bloodstream Inflammatory response to their presence.

Inflammatory Response Localized: Rubor, Calor, Dolor, Tumor, and functio laesa (loss of function) Systemic: Systemic Inflammatory Response Syndrome (SIRS)

S.I.R.S. Any Two of the Following Criteria Temperature: < 36.0, >38.0 Heart Rate : >90 Respiratory Rate: >20 WBC: <4,000, >12,000

Sepsis Definition: SIRS plus evidence of local or systemic infection. Septic Shock Definition: Sepsis plus end organ hypoprofusion. Mortality of up to 40%

Soft Tissue Infections: Cellulitis Abscess Necrotizing Infections

Cellulitis

Cellulitis Definition: Diffuse infection with severe inflammation of dermal and subcutaneous layers of the skin Diagnosis: Pain, Warmth, Hyperesthesia Treatment: Antibiotics. Common Pathogens: Skin Flora (Streptococcus/Staphylococcus)

Abscess

Abscess Definition: Infectious accumulation of purulent material (Neutrophils) in a closed cavity Diagnosis: Fluctuant: Moveable and compressible Treatment: Drainage

Necrotizing Soft Tissue Infection

Necrotizing Soft Tissue Infection Definition: Deep infection of skin and soft tissue that may spread rapidly along facial planes. Diagnosis: Purely Clinical, dishwater discharge, gray tissue, pain out of proportion to examination, bulla, and dark, golden discoloration. Treatment: True Surgical Emergency, Antibiotics

Necrotizing Soft Tissue Infection Common Pathogens Clostridium Group A streptococcus Polymicrobial

Post-Operative Infections Fever After Surgery The “Five W’s” Wind: Atelectisis Water: UTI Walking: DVT Wonder Drug: Medication Induced Wound: Surgical Site Infection

Surgical Site Infection(SSI) : Infection at or near the site of surgery that occurs within 30 days of surgery if there is no implant (hardware, artificial graft, mesh, etc) OR occurs within 3 months of the surgery with an implant in place From CDC’s NNIS

Patients that develop SSI have twice the mortality and are: Why Prevent SSIs? Approximately 500,000 surgical site infections (SSI) occur annually in the United States Patients that develop SSI have twice the mortality and are: 60% more likely to spend time in ICU 5 times more likely to be readmitted

Surgical Site Infections 3rd most common hospital infection Incisional Superficial Deep Organ Space Generalized (peritonitis) Abscess

Cross Section of Abdominal Wall Depicting CDC SSI Classifications

Superficial Incisional SSI Infection occurs within 30 days after the operation and involves only skin or subcutaneous tissue of the incision Superficial incisional SSI Skin Subcutaneous tissue The first type of surgical site infection is the superficial incisional surgical infection which occurs within 30 days post-op and involves only the skin or subcutaneous tissue. Mangram AJ et al. Infect Control Hosp Epidemiol. 1999;20:250-278.

Deep Incisional SSI Infection occurs within 30 days after the operation if no implant is left in place or within 3 months if implant is in place and the infection appears to be related to the operation and the infection involves the deep soft tissue (e.g., fascia and muscle layers) Deep incisional SSI Superficial incisional SSI A more serious SSI is a deep incisional surgical infection, which extends past the superficial layer. The infection occurs within 30 days post-op only if no implant is left in place or within 1 year if implant is in place and the infection appears to be related to the operation and the infection involves the deep soft tissue, which include the fascia and muscle layers. Deep soft tissue (fascia & muscle) Mangram AJ et al. Infect Control Hosp Epidemiol. 1999;20:250-278.

Organ/Space SSI Infection occurs within 30 days after the operation if no implant is left in place or within 3months if implant is in place and the infection appears to be related to the operation and the infection involves any part of the anatomy, other than the incision, which was opened or manipulated during the operation Superficial incisional SSI Deep incisional SSI The most extensive of these surgical infections involves the organs and the space surrounding the organs. These infections can occur within 30 days post-op if no implant is left in place or within 1 year if an implant is in place and the infection appears to be related to the operation and the infection involves any part of the anatomy, other than the incision, which was opened or manipulated during the operation. Organ/space SSI Organ/space Mangram AJ et al. Infect Control Hosp Epidemiol. 1999;20:250-278.

Risk factors endogenous contamination (for example, procedures that involve parts of the body with a high concentration of normal flora such as the bowel) exogenous contamination (for example, prolonged operations that increase the length of time that tissues are exposed)

diminish the  general immune response (for example, diabetes, malnutrition, or immunosuppressive therapy with radiotherapy, chemotherapy or steroids) or local immune response (for example, foreign bodies, damaged tissue or formation of a haematoma).

Host Risk Factors Diabetes mellitus Hypoxemia Hypothermia Leukopenia Nicotine (tobacco smoking) Immunosuppression Malnutrition Poor skin hygiene

Perioperative Risk Factors Operative site shaving Breaks in operative sterile technique Improper antimicrobial prophylaxis Prolonged hypotension Contaminated operating room Poor wound care postoperatively Hyperglycemia Wound closure technique

Operative Antibiotic Prophylaxis Decreases bacterial counts at surgical site Given within 30 minutes prior to starting surgery Vancomycin 1-2 hours prior to surgery Redose for longer surgery Do not continue beyond 24 hours

Principles of Antibiotic Prophylaxis Preop administration, serum levels adequate throughout procedure with a drug active against expected microorganisms. High Serum Levels Preop timing IV route Highest dose of drug During Procedure Long half-life Long procedure–redose Large blood loss–redose Duration None after wound closed 24 hours maximum Mangram AJ et al. Infect Control Hosp Epidemiol. 1999;20:250-278.

Treatment Incisional: open surgical wound, antibiotics for cellulitis or sepsis Deep/Organ space: Source control, antibiotics for sepsis

Use/Choice of Antibiotics Use only when indicated Start with broad spectrum antibiotics designed to cover likely pathogens Take cultures when possible Deescalate spectrum once pathogen is know Have a plan for duration

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