What is the best antibiotic regimen for the treatment of surgical site infections, infected blood prostheses, or infection hematomas?

From the Guidelines

The best antibiotic regimen for surgical site infections, infected blood prostheses, or infected hematomas typically involves empiric broad-spectrum coverage followed by targeted therapy based on culture results, with vancomycin (15-20 mg/kg IV every 8-12 hours) plus piperacillin-tazobactam (4.5g IV every 6-8 hours) being the recommended initial combination. This approach is based on the most recent and highest quality study available, which prioritizes the management of these infections to minimize morbidity, mortality, and improve quality of life 1.

Key Considerations

• The initial antibiotic regimen should cover MRSA, gram-negative organisms, and anaerobes, as these are common pathogens in surgical site infections, infected blood prostheses, or infected hematomas.
• For penicillin-allergic patients, alternative regimens such as meropenem (1g IV every 8 hours) or cefepime (2g IV every 8-12 hours) plus metronidazole (500mg IV every 8 hours) can be used.
• The treatment duration varies depending on the type of infection, with uncomplicated surgical site infections typically requiring 7-14 days of therapy, while infected prostheses often require 4-6 weeks of therapy and may necessitate surgical intervention for definitive management, as outlined in guidelines for the management of prosthetic joint infections 1.
• Infected hematomas generally require drainage in addition to antibiotics, and monitoring for clinical improvement within 48-72 hours is essential to assess the need for surgical intervention.

Pathogen-Specific Therapy

• Once culture results are available, therapy should be narrowed to the specific pathogen(s) to minimize the development of antibiotic resistance.
• For example, if the infection is caused by methicillin-susceptible Staphylococcus aureus (MSSA), a first-generation cephalosporin or an antistaphylococcal penicillin can be used, while vancomycin, linezolid, daptomycin, telavancin, or ceftaroline can be used for infections caused by MRSA, especially in patients with risk factors for MRSA 1.
• The choice of antibiotic regimen should be guided by the susceptibility patterns of the isolated pathogens, as well as the clinical response to therapy.

From the FDA Drug Label

14 CLINICAL STUDIES 14. 1 Complicated Skin and Skin Structure Infections

Adult patients with clinically documented complicated skin and skin structure infections (cSSSI) (Table 15) were enrolled in two randomized, multinational, multicenter, investigator-blinded trials comparing daptomycin for injection (4 mg/kg IV q24h) with either vancomycin (1 g IV q12h) or an anti-staphylococcal semi-synthetic penicillin (i.e., nafcillin, oxacillin, cloxacillin, or flucloxacillin; 4 to 12 g IV per day).

The best antibiotic regimen for the treatment of surgical site infections, infected blood prostheses, or infection hematomas is not directly stated in the provided drug label. However, based on the information provided, daptomycin can be considered as an option for the treatment of complicated skin and skin structure infections (cSSSI).

• The clinical success rates in the intent-to-treat (ITT) population were 62.5% (165/264) in patients treated with daptomycin for injection and 60.9% (162/266) in patients treated with comparator drugs.
• The success rates by pathogen for microbiologically evaluable patients show that daptomycin has a high success rate against various pathogens, including Methicillin-susceptible Staphylococcus aureus (MSSA) and Methicillin-resistant Staphylococcus aureus (MRSA) 2. However, it is essential to note that the provided drug label does not directly address the treatment of surgical site infections, infected blood prostheses, or infection hematomas. Therefore, the use of daptomycin for these specific conditions should be approached with caution and considered on a case-by-case basis.

From the Research

Antibiotic Regimens for Surgical Site Infections

• The best antibiotic regimen for the treatment of surgical site infections, infected blood prostheses, or infection hematomas is not universally defined, but several studies provide guidance on effective treatments 3, 4, 5, 6, 7.
• For methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections, vancomycin + β-lactam combinations, such as vancomycin + cefepime, have been shown to improve clearance of MRSA and reduce microbiologic failure 3.
• In the case of infected vascular prostheses, broad-spectrum antibiotics should be started immediately, with modification based on culture and sensitivity results, and removal of the infected prosthesis is often necessary 4.
• The combination of meropenem with gentamicin or vancomycin has been shown to enhance the killing action of meropenem against Pseudomonas aeruginosa and Staphylococcus aureus 5.
• Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) are common healthcare-associated multidrug-resistant organisms, and reduced susceptibility to vancomycin among MRSA isolates has been associated with glycopeptide treatment failure 6.
• The Centers for Disease Control and Prevention (CDC) has updated guidelines for preventing surgical site infections, which are the most common healthcare-associated infections experienced by patients who undergo surgery 7.

Considerations for Antibiotic Selection

• The choice of antibiotic regimen should be based on the specific causative organism, the severity of the infection, and the patient's underlying health status.
• Combination therapy, such as vancomycin + β-lactam, may be beneficial in certain cases, such as MRSA bloodstream infections.
• Broad-spectrum antibiotics should be used judiciously and modified based on culture and sensitivity results to minimize the risk of antibiotic resistance.
• Removal of infected prostheses or other foreign material may be necessary to achieve effective treatment of surgical site infections.