The levels of evidence (A-C) and classification of recommendations (I-III) are defined at the end of the "Major Recommendations" field.
Choice of Primary Prophylactic Antibiotic
Cephalosporin or Glycopeptide
Class I Recommendation
A beta-lactam antibiotic is indicated as a single antibiotic of choice for standard cardiac surgical prophylaxis in populations that do not have a high incidence of methicillin-resistant staphylococcus aureus (MRSA) (Level of Evidence A).
Distinguishing Between Cephalosporins
Class IIa Recommendation
Based on availability and cost, it is reasonable to use cefazolin (a first generation agent) as the cephalosporin for standard cardiac surgical prophylaxis in view of the fact that most randomized trials could not discriminate between cephalosporins (Level of Evidence B).
Issues Surrounding Staphylococcal Infection
Potential (Non-allergic) Indications for Primary or Adjuvant Glycopeptide (Vancomycin) Prophylaxis
Class IIb Recommendation
In the setting of either a presumed or known Staphylococcal colonization, the institutional presence of a "high incidence" of MRSA, patients susceptible to colonization (hospitalized >3 days, transfer from other in-patient facility, already receiving antibiotics), or an operation for a patient having prosthetic valve or vascular graft insertion, it would be reasonable to combine the beta-lactam (cefazolin) with a glycopeptide (vancomycin) for prophylaxis, with the restriction to limit vancomycin to only one or two doses (Level of Evidence C).
Vancomycin as the Sole Prophylactic Antibiotic
Class IIb Recommendation
Since vancomycin is an agent which has no effect on gram negative flora, its usefulness as an exclusive agent in cardiac surgical prophylaxis is not recommended (Level of Evidence C).
Mupirocin for Preoperative Therapy to Eliminate Staphylococcal Nasal Colonization
Class I Recommendation
Routine mupirocin administration is recommended for all patients undergoing cardiac surgical procedures in the absence of a documented negative testing for Staphylococcal colonization (Level of Evidence A).
Guidelines for Appropriate Dosing of Prophylactic Antibiotics
Recommendations:
- In patients for whom cefazolin is the appropriate prophylactic antibiotic for cardiac surgery, administration within 60 minutes of the skin incision is indicated (Class I, Level of Evidence A). The preoperative prophylactic dose of cefazolin for a patient >60 kg body weight (BW) is recommended to be 2 g (Class I, Level of Evidence B).
- When the surgical incision remains open in the operating room, in patients with normal renal function, a second dose of one gram should be administered every 3 to 4 hours. If it is apparent that cardiopulmonary bypass will be discontinued within 4 hours, it is appropriate to delay until perfusion is complete to maximize effective blood levels (Class I, Level of Evidence B).
- In patients for whom vancomycin is an appropriate prophylactic antibiotic for cardiac surgery, a dose of 1 to 1.5 grams or a weight adjusted dose of 15 mg/kg, administered intravenously (I.V.) slowly over one hour, with completion within one hour of the skin incision is recommended (Class I, Level of Evidence A). A second dose of vancomycin of 7.5 mg/kg may be considered during cardiopulmonary bypass although its usefulness is not well established (Class IIb, Level of Evidence C).
- For patients who receive an aminoglycoside (usually gentamicin, 4 mg/kg) in addition to vancomycin prior to cardiac surgery, the initial dose should be administered within one hour of the skin incision (Class I, Level of Evidence C). Redosing an aminoglycoside during cardiopulmonary bypass is not indicated and may be harmful (Class III, Level of Evidence C).
Guidelines for Prophylactic Antibiotics in Special Circumstances
Allergy to Penicillin
Recommendations:
- In patients with a history of an immunoglobulin E (IgE)-mediated reaction to penicillin or cephalosporin (anaphylaxis, hives, or angioedema), vancomycin should be given preoperatively and for no more than 48 hours. Alternatively, skin testing may be performed in these patients and if negative, a cephalosporin regimen administered (Class I, Level of Evidence A).
- For patients with a history of a non-IgE mediated reaction to penicillin (such as a simple rash) or an unclear history either vancomycin or a cephalosporin is recommended for prophylaxis with the understanding that these patients have a low incidence of significant allergic reactions to cephalosporins (Class I, Level of Evidence B).
- The addition of an aminoglycoside or other gram-negative bacterial coverage to a vancomycin antibiotic regimen may be reasonable, but its efficacy is not well established (Class IIb, Level of Evidence C).
Specific Issues Regarding Gram Negative Infections
Recommendations:
- For institutions with an outbreak of gram-negative deep wound infections due to a specific pathogen, it is reasonable to employ a first generation cephalosporin for routine prophylaxis (<48 hours) supplemented with an appropriate antibiotic to which the offending organism(s) is (are) sensitive (Class IIa, Level of Evidence C).
- In patients with renal dysfunction requiring gram negative prophylaxis to supplement a cephalosporin or vancomycin as the primary antibiotic, it is reasonable to use either one dose of an aminoglycoside or an antibiotic such as levofloxacin with a low incidence of renal toxicity (Class IIa, Level of Evidence C).
Topical Application of Antibiotics
Class IIb Recommendation
Topical antibiotics may be considered for antibiotic prophylaxis in cardiac surgery (Level of Evidence B).
Summary Conclusions
The primary prophylactic antibiotic for adult cardiac surgery is recommended to be a first generation cephalosporin, which is usually cefazolin. The most frequent organism cultured in cardiac surgical site infection (SSI) is Staphylococcus sp., and colonization is considered the major factor in wound contamination. For this reason, until rapid screening tests for Staphylococcus aureus colonization are widely available, mupirocin is recommended as a routine prophylactic measure. In patients considered at high risk for a Staph infection, vancomycin (one preoperative +/- one additional dose) may be reasonable as an adjuvant agent to the cephalosporin. In patients who are considered beta-lactam or penicillin allergic, vancomycin is recommended as the primary prophylactic antibiotic with additional gram negative coverage. Topical antibiotics may be useful, but the evidence to support their efficacy is limited to three randomized trials.
Definitions:
Levels of Evidence
Level A: Data derived from multiple randomized clinical trials
Level B: Data derived from a single randomized trial or from nonrandomized trials
Level C: Consensus expert opinion
Classification of Recommendations
Class I: Conditions for which there is evidence and/or general agreement that a given procedure is useful and effective
Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure
IIa: Weight of evidence favors usefulness/efficacy.
IIb: Usefulness/efficacy is less well established by evidence.
Class III: Conditions for which there is evidence and/or general agreement that the procedure is not useful/effective
