Pre-Operative Antibiotic prophylaxis Dr.E.Shojaei Assistant Prof. of Infectious Diseases T.U.M.S

Patient factorsEnvironmental factorsTreatment factors AscitesContaminated medicationsEmergency procedure Chronic inflammation Inadequate disinfection/sterilization Failure to obliterate dead space Coexistent remote infectionInadequate skin antisepsisHypothermia Colonization with microorganismsInadequate ventilationInadequate antibiotic prophylaxis Corticosteroid therapyIntraoperative blood transfusion DiabetesOxygenation Extended preoperative admissionPoor hemostasis HypocholesterolemiaProlonged operative time HypoxemiaSurgical drains MalnutritionTissue trauma Obesity Peripheral vascular disease Perioperative anemia Preoperative shaving Prior site irradiation Recent operation Skin disease in the area of infection (e.g., psoriasis) Am J Infect Control 29: , 2001; Infect Control Hosp Epidemiol 20(4): , 1999.

Antimicrobial prophylaxis may be beneficial in surgical procedures associated with a high rate of infection (i.e., clean- contaminated or contaminated procedures) and in certain clean procedures where there are severe consequences of infection (e.g., prosthetic implants), even if infection is unlikely.

Which antibiotic use? Active against the pathogens most likely to contaminate the surgical site Given in an appropriate dosage and at a time that ensures adequate serum and tissue concentrations during the period of potential contamination Safe administered for the shortest effective period to minimize adverse effects, the development of resistance, and costs

Routine use of vancomycin prophylaxis is not recommended for any procedure Vancomycin may be included in the regimen of choice when a cluster of MRSA cases or methicillin resistant coagulase- negative staphylococci SSIs have been detected at an institution

Although vancomycin is commonly used when the risk for MRSA is high, data suggest that vancomycin is less effective than cefazolin for preventing SSIs caused by methicillin-susceptible S. aureus (MSSA) vancomycin is used in combination with cefazolin at some institutions with both MSSA and MRSA SSIs

Surgical prophylaxis can also predispose patients to Clostridium difficile-associated colitis Limiting the duration of antimicrobial prophylaxis to a single preoperative dose can reduce the risk of C. difficile disease

MDR gram Neg colonizers: There is no evidence on the management of surgical antimicrobial prophylaxis in a patient with past infection or colonization with a resistant gram-negative pathogen

Known colonizers for MRSA It is logical to provide prophylaxis with an agent active against MRSA for any patient known to be colonized with this gram- positive pathogen who will have a skin incision

VRE colonizers: case-by-case basis A patient colonized with vancomycin- resistant enterococci (VRE) should receive prophylaxis effective against VRE when undergoing liver transplantation but probably not when undergoing an umbilical hernia repair without mesh placement.

Administration of the first dose of antimicrobial beginning within 60 minutes before surgical incision is recommended Administration of vancomycin and fluoroquinolones should begin within 120 minutes before surgical incision because of the prolonged infusion times required for these drugs

Redosing The redosing interval should be measured from the time of administration of the preoperative dose, not from the beginning of the procedure If the duration of the procedure exceeds two half-lives of the antimicrobial or there is excessive blood loss (i.e., >1500 mL).

Duration Postoperative antimicrobial administration is not necessary for most procedures The duration of antimicrobial prophylaxis should be less than 24 hours for most procedures

Common surgical pathogens SSIs after clean procedures are skin flora, including S. aureus and coagulase- negative staphylococci Clean-contaminated procedures, including abdominal procedures and heart, kidney, and liver transplantations, the predominant organisms include gram negative rods and enterococci in addition to skin flora

Common surgical pathogens If there are surveillance data showing that gram-negative organisms are a cause of SSIs for the procedure, practitioners may consider combining vancomycin with another agent (cefazolin if the patient does not have a b-lactam allergy; an aminoglycoside [gentamicin or tobramycin], aztreonam, or single-dose fluoroquinolone if the patient has a b-lactam allergy).

Appendectomy procedures The most common microorganisms isolated from SSIs after appendectomy are anaerobic and aerobic gram- negative enteric organisms. Bacteroides fragilis is the most commonly cultured anaerobe, and E. coli is the most frequent aerobe

Appendectomy procedures single dose of a cephalosporin with anaerobic activity (cefoxitin or cefotetan) Or single dose of a first-generation cephalosporin (cefazolin) plus metronidazole

Small intestine procedures For small bowel surgery without obstruction, the recommended regimen is a first-generation cephalosporin (cefazolin) For small bowel surgery with intestinal obstruction, the recommended regimen is a cephalosporin with anaerobic activity (cefoxitin or cefotetan) or the combination of a first-generation cephalosporin (cefazolin) plus metronidazole.

Colorectal procedures Bacteroides fragilis and other obligate anaerobes are the most frequently isolated organisms from the bowel, with concentrations 1,000–10,000 times higher than those of aerobes

Colorectal procedures A single dose of second-generation cephalosporin with both aerobic and anaerobic activities (cefoxitin or cefotetan) or Cefazolin plus metronidazole is recommended for colon procedures

Colorectal procedures In institutions where there is increasing resistance to first- and second-generation cephalosporins among gram-negative isolates from SSIs, the expert panel recommends a single dose of ceftriaxone plus metronidazole An alternative regimen is ampicillin– sulbactam.

Colorectal procedures The efficacy of oral prophylactic antimicrobial agents has been established in studies only when used with mechanical bowel preparation (MBP). Combination of oral neomycin sulfate(1gr) plus oral erythromycin base (1gr) Or Oral neomycin sulfate(1gr) plus oral metronidazole(1gr) should be given in addition to i.v. prophylaxis

Head and neck procedures Clean-contaminated procedures (1) cefazolin or cefuroxime plus metronidazole Or (2) ampicillin–sulbactam.

Urologic procedures Patients with preoperative bacteriuria or UTI should be treated before the procedure, when possible, to reduce the risk of postoperative infection

Urologic procedures For patients undergoing lower urinary tract instrumentation with risk factors for infection, the use of a fluoroquinolone or trimethoprim– sulfamethoxazole (oral or i.v.) or cefazolin (i.v. or intramuscular) is recommended

Liver transplantation The pathogens most commonly associated with early SSIs and intraabdominal infections are those derived from the normal flora of the intestinal lumen and the skin. Aerobic gram-negative bacilli, including E. coli,Klebsiella species, Enterobacter species, A. baumannii and Citrobacter species Staphylococcus aureus (frequently MRSA) and coagulase-negative staphylococci are also common causes of postoperative SSIs Candida species commonly cause both early and late postoperative infections

Liver transplantation Majority of recent studies have limited the duration of prophylaxis to 72 h (1) piperacillin–tazobactam or (2) cefotaxime plus ampicillin

Liver transplantation For patients at high risk of Candida infection, fluconazole may be considered. (Strength of evidence B.)

Cesarean delivery procedures The infection rate after cesarean delivery has been reported to be 4–15% Endometritis (infection of the uterine lining) is usually identified by fever, malaise, tachycardia, abdominal pain, uterine tenderness, and sometimes abnormal or foul-smelling lochia. Fever may also be the only symptomof endometritis.

The recommended regimen for all women undergoing cesarean delivery is a single dose of cefazolin administered before surgical incision.(Strength of evidence for prophylaxis = A.) For patients with b-lactam allergies, an alternative regimen is clindamycin plus gentamicin

Induced (Therapeutic) Abortion All women undergoing an induced (therapeutic) surgical abortion should receive prophylactic antibiotics to reduce the risk of postabortal infection. (I-A)

Missed or Incomplete Abortion Prophylactic antibiotics are not suggested to reduce infectious morbidity following surgery for a missed or incomplete abortion.

Intrauterine Device Insertion Antibiotic prophylaxis is not recommended for insertion of an intrauterine device. (I-E) However, health care professionals could consider screening for sexually transmitted infections in high-risk populations. (III-C)

Endometrial Biopsy There is insufficient evidence to support the use of antibiotic prophylaxis for an endometrial biopsy.