Surgical prophylaxis

Antibiotics administered before contamination of previously sterile tissues or fluids are considered prophylactic. The goal for prophylactic antibiotics is to prevent a surgical-site infection (SSI) from developing. 

Presumptive antibiotic therapy is administered when an infection is suspected but not yet proven. Therapeutic antibiotics are required for established infection. 

SSls are classified as either incisional (such as ceUuhtis of the incision site) or involving an organ or space (such as with meningitis). Incisional SSls may be superficial (skin or subcutaneous tissue) or deep (fascial and muscle layers). Both types, by definition, occur by postoperative day 30. This period extends to 1 year in the case of deep infection associated with prosthesis implantation. 

The traditional classification system developed by the National Research Council (NRC) stratifying surgical procedures by infection risk is reproduced in Table 48-1. The NRC wound classification for a specific procedure is determined intraoperatively and is the primary determinant of 

The Study on the Efficacy of Nosocomial Infection Control (SENIC) analyzed more than 100,000 surgery cases and identified abdominal operations, operations lasting more than 2 hours, contaminated or dirty procedures, and more than three underlying medical diagnoses as factors associated with an increased incidence of SSI. When the NRC classification described in T able 48-1 was stratified by the number of SENIC risk factors present, the infection rates varied by as much as a factor of 15 within the same operative category. 

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CNS, intracranial, retropharyngeal, retroperitoneal, surgical prophylaxis 80%-100% 80%-100% Factor VIII q8-12 hours over 10-14 days Factor IX q12 hours over 10-14 days... 

Compare and contrast antimicrobials used for surgical prophylaxis and identify potential advantages and disadvantages for each antibiotic. 

The goal of antimicrobial dosing for surgical prophylaxis is to maintain antibiotic concentrations above the minimum inhibitory concentration (MIC) of suspected organisms for the duration of the operation. 

Newer antimicrobials have not demonstrated superiority in the prevention of SSI and should be reserved for treatment only. Carbapenems, antipseudomonal penicillins, and third-or fourth-generation cephalosporins are not appropriate antibiotics for surgical prophylaxis. Overuse of these antibiotics may contribute to collateral damage and the development of bacterial resistance. 

Intravenous antibiotic administration is the most common delivery method for surgical prophylaxis. Intravenous administration ensures complete bioavailability while minimizing the impact of patient-specific variables. Oral administration is also used in some bowel operations. Non-absorbable compounds like erythromycin base and neomycin are given up to 24 hours prior to surgery to cleanse the bowel. Note that oral agents are used adjunctively and do not replace IV agents. 

Correct timing of antibiotic administration is imperative to preventing SSI. The National Surgical Infection Prevention Project recommends infusing antimicrobials for surgical prophylaxis within 60 minutes of the first incision. Exceptions to this rule are fluoroquinolones and vancomycin, which can be infused 120 minutes prior to avoid infusion-related reactions.1 No consensus has been reached on whether the infusion should be complete prior to the first incision. However, if a proximal tourniquet is used, antibiotic administration should be complete prior to inflation. 

Refacto Antihemophilic factor Genetics Institute Hemorrhagic episodes and surgical prophylaxis in patients with hemophilia A... 

As outlined in the excellent review by Gilles and Brogden [9], the current indications for rifaximin include surgical prophylaxis and the treatment of hepatic encephalopathy, infectious diarrhea and intestinal bacterial overgrowth syndromes. As such, rifaximin is aimed only at enteric flora. Owing to its lack of absorption, rifaximin will likely not be used for other conditions or indications. Such limited indications should help preserve the activity of the agent, since overuse for common conditions like urinary or respiratory tract infections will naturally not occur. Limited use should help retard the development of resistance among enteric flora. 

The following principles must be considered when providing antimicrobial surgical prophylaxis ... 

Typically, gram-positive coverage is included in the choice of surgical prophylaxis, because organisms such as S. aureus and S. epidermidis are common skin flora. 

Most Likely Pathogens and Specific Recommendations for Surgical Prophylaxis... 

Surgical prophylaxis Give a single 1 g dose to 2 hours before surgery. 

The minimally required duration of treatment is only known for a limited number of infections. Clinical trials have shown the effectiveness of a single dose in the treatment of gonorrhoea or uncomplicated urinary tract infection in women and in surgical prophylaxis. The more precise duration of treatment has been studied for endocarditis, meningitis and staphylococcal bacteraemia. More often, guidelines for duration of treatment have been based on clinical experience with similar infections and on the parameters of response mentioned above. Failure of treatment should be recognised early. It can be due to a variety of reasons (Table 2). 

Prophylaxis is defined as antibiotics used to prevent infection. The reasons to administer prophylaxis can be the same for surgical and non-surgical prophylaxis, and for immunocompetent or immunocompromised hosts alike. These reasons are ... 

As prophylaxis is intended to prevent the spread and/or multiplication of bacteria in blood and tissues, timing of its administration is crucial. For surgical prophylaxis the maximal effect is obtained when the antibiotic is in the tissues before contamination occurs (before incision of the skin). Adequate antibiotic levels should be in the blood at the start of an invasive diagnostic procedure in the GI tract to combat bacteraemia. 

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