What is the role of oral antibiotic prophylaxis in cardiac surgery?

From the Guidelines

Oral antibiotic prophylaxis plays a crucial role in reducing the risk of surgical site infections in cardiac surgery, and its use is recommended for patients undergoing placement of prosthetic heart valves or prosthetic intravascular or intracardiac materials. The most recent and highest quality study, 1, published in 2017, provides guidance on the use of antibiotic prophylaxis in patients with valvular heart disease. According to this study, prophylaxis against infective endocarditis is reasonable before dental procedures that involve manipulation of gingival tissue, manipulation of the periapical region of teeth, or perforation of the oral mucosa in patients with prosthetic cardiac valves, including transcatheter-implanted prostheses and homografts.

Key Considerations

• The choice of antibiotic should be influenced by the antibiotic susceptibility patterns at each hospital, with a first-generation cephalosporin being the most commonly used option 1.
• For patients with beta-lactam allergies, vancomycin or clindamycin can be used as alternatives.
• Prophylaxis should be initiated immediately before the operative procedure, repeated during prolonged procedures to maintain serum concentrations intraoperatively, and continued for no more than 48 hours postoperatively to minimize the emergence of resistant microorganisms 1.
• The effects of cardiopulmonary bypass and compromised renal function on antibiotic concentrations in serum should be considered, and dosages adjusted as necessary before and during the procedure.

Recommendations

• For most cardiac surgeries, prophylaxis should be discontinued within 48 hours after surgery to minimize the risk of developing antibiotic resistance.
• Effective antibiotic prophylaxis targets common skin flora, particularly Staphylococcus species, which are the predominant pathogens in cardiac surgical infections.
• Proper timing ensures adequate tissue and blood concentrations of antibiotics at the time of incision and throughout the procedure.
• Patients at risk of developing bacterial infective endocarditis should establish and maintain the best possible oral health to reduce potential sources of bacterial seeding, through regular professional dental care and the use of appropriate dental products 1.

From the FDA Drug Label

The perioperative use of Cefuroxime for Injection, USP has also been effective during open heart surgery for surgical patients in whom infections at the operative site would present a serious risk. The prophylactic administration of Cefazolin for Injection, USP also may be effective in surgical patients in whom infection at the operative site would present a serious risk (e.g., during open-heart surgery and prosthetic arthroplasty).

The role of oral antibiotic prophylaxis in cardiac surgery is not explicitly stated in the provided drug labels, as they discuss intravenous (IV) antibiotic prophylaxis. However, based on the information provided for IV antibiotics, antibiotic prophylaxis is used to reduce the incidence of postoperative infections in cardiac surgery. The recommended duration of prophylactic administration varies, but it is usually discontinued within 24 hours after the surgical procedure, or continued for at least 48 hours or 3 to 5 days in certain cases, such as open-heart surgery 2 3. Key points include:

• Intravenous antibiotic prophylaxis is effective in reducing postoperative infections in cardiac surgery
• Duration of prophylaxis varies depending on the surgical procedure and patient risk factors
• Oral antibiotic prophylaxis is not discussed in the provided drug labels, and its role in cardiac surgery is unclear based on this information.

From the Research

Role of Oral Antibiotic Prophylaxis in Cardiac Surgery

• There is limited evidence on the specific role of oral antibiotic prophylaxis in cardiac surgery, as most studies focus on parenteral antibiotic prophylaxis 4, 5, 6, 7, 8.
• However, one study mentions that oral prophylaxis in bowel surgery may offer additional protection by reducing colonic flora 5.
• The majority of the evidence suggests that parenteral antibiotic prophylaxis, such as cephalosporins, is effective in preventing surgical site infections in cardiac surgery 4, 6, 8.
• The choice of antibiotic and timing of administration are crucial in preventing surgical site infections, with some studies suggesting that administration within 30 minutes before incision is more effective 6.
• The duration of prophylaxis is also important, with some studies suggesting that prolongation up to 48 hours post-operatively may be beneficial 8.

Types of Antibiotics Used

• Cephalosporins, particularly second- or third-generation, are commonly used for cardiac surgery prophylaxis 4, 6, 8.
• Vancomycin may be used in patients allergic to cephalosporins or in cases where methicillin-resistant Staphylococcus aureus (MRSA) is suspected 4, 8.
• The combination of antibiotics, such as vancomycin and cefuroxime, may be used in certain situations, but the evidence is limited 6.

Special Considerations

• In pediatric cardiac surgery, the optimal schedule for antibiotic prophylaxis has not been defined, and further research is needed 7.
• In cases where patients have a history of allergy or colonization with resistant organisms, alternative antibiotic regimens may be necessary 7.