Daptomycin as supportive treatment option in patients developing mediastinitis after open cardiac surgery

Antibiotic therapy in reconstructive surgery of deep sternal wound infections

BACKGROUND

The choice of antibiotics and length of administration in the treatment of deep sternal wound infections (DSWI) is unclear. The reason for this is the lack of studies and local differences in resistance. An increase in resistance can be observed in gram-positive cocci, which are the most frequently detected in deep sternal infections. The duration of administration is often 2- 6 weeks or longer, although the benefit of prolonged antibiotic administration has not been confirmed by studies. We evaluated the antibiotic treatment during surgical treatment, consisting of surgical wound debridement and plastic chest reconstruction.

METHODS

Retrospective analysis of patients (n = 260) who underwent reconstructive surgery in the Department of Plastic Surgery at Leipzig University Hospital from 01.05.2012 - 31.12.2020. The duration of intake, results of microbiological swabs and resistance were investigated.

RESULTS

At the time of discharge, closed wound conditions were noted in 177 of 260 cases (68.1%). The largest proportion of patients (n = 238) was treated with a latissimus dorsi flap (91.5%).Antibiotic treatment was conducted in 206 of 260 cases (79.2%). The mean duration of antibiotic administration was 21.4 days (±17.6). Prolonged treatment over 14 days did not alter outcome (p = 0.226), in contrast, the number of multidrug resistances (p < 0.001). There was no prove of resistance against linezolid which is effective against the most common found infectious agents Staphylococcus epidermidis (n = 93; 24.0 %) & Staphylococcus aureus (n = 47; 12.1 %).

CONCLUSION

There is no evidence of benefit from antibiotic therapy over 14 days, whereas multidrug resistance increases with prolonged antibiotic use. In the absence of infectious agents or clinical signs of inflammation, surgical treatment without additional antibiotic treatment is effective.Linezolid is a suitable antibiotic in the treatment of gram-positive infections which are the most frequent in DSWI.

Prevention, Diagnosis and Management of Post-Surgical Mediastinitis in Adults Consensus Guidelines of the Spanish Society of Cardiovascular Infections (SEICAV), the Spanish Society of Thoracic and Cardiovascular Surgery (SECTCV) and the Biomedical Research Centre Network for Respiratory Diseases (CIBERES)

This is a consensus document of the Spanish Society of Cardiovascular Infections (SEICAV), the Spanish Society of Thoracic and Cardiovascular Surgery (SECTCV) and the Biomedical Research Centre Network for Respiratory Diseases (CIBERES). These three entities have brought together a multidisciplinary group of experts that includes anaesthesiologists, cardiac and cardiothoracic surgeons, clinical microbiologists, infectious diseases and intensive care specialists, internal medicine doctors and radiologists. Despite the clinical and economic consequences of sternal wound infections, to date, there are no specific guidelines for the prevention, diagnosis and management of mediastinitis based on a multidisciplinary consensus. The purpose of the present document is to provide evidence-based guidance on the most effective diagnosis and management of patients who have experienced or are at risk of developing a post-surgical mediastinitis infection in order to optimise patient outcomes and the process of care. The intended users of the document are health care providers who help patients make decisions regarding their treatment, aiming to optimise the benefits and minimise any harm as well as the workload.

Daptomycin for the treatment of major gram-positive infections after cardiac surgery

Background

Infection is a main cause of morbidity and mortality after heart surgery, with multi-resistant pathogens increasingly representing a challenge. Daptomycin provides bactericidal activity against gram-positive organisms that are resistant to standard treatment including vancomycin.

Methods

A cohort of cardiac surgical patients, treated with daptomycin for major infection at two tertiary care centers, were retrospectively studied with a particular focus on the type of infection, causative pathogens and co-infections, daptomycin dosage, adverse events and outcome in order to provide evidence for the efficiency and safety of daptomycin in a distinct high-risk patient population.

Results

Sixty-five patients (87.7 % males, 60.4 ± 13.5 years) who had undergone aortic surgery (20.0 %), ventricular assist device (VAD) implantation (21.5 %), combined procedures (21.5 %), coronary artery bypass grafting (12.3 %), isolated valve surgery (15.4 %) and heart transplantation (7.7 %) were diagnosed with catheter-related infection (26.1 %), valve endocarditis (18.8 %), sternal wound (13.0 %), VAD-associated (11.6 %), cardiac implantable electrophysiological device (CIED)-associated (4.1 %), respiratory tract (4.3 %), bloodstream (4.3 %) and other infection (4.3 %). In 13.0 %, no focus of infection was identified though symptoms of severe infection were present. The most frequent pathogens were Staphylococcus epidermidis (30.4 %), Staphylococcus aureus (23.1 %) and Enterococcus species (10.1 %). Daptomycin doses ranging from 3 mg/kg every 48 h to 10 mg/kg every 24 h were administered for 15.4 ± 11.8 days. 87.0 % of the cases were classified as success, 7.2 % as treatment failure and 5.8 as non-evaluable. Adverse events were limited to one case of mild and one case of moderate neutropenia with recovery upon termination of treatment.

Conclusion

Daptomycin proved safe and effective in major infection in high-risk cardiac surgical patients.

[Rational antibiotic treatment of mediastinitis]

Mediastinitis occurs as a severe complication of thoracic and cardiac surgical interventions and is the result of traumatic esophageal perforation, conducted infections or as a result of lymphogenic and hematogenic spread of specific infective pathogens. Treatment must as a rule be accompanied by antibiotics, whereby knowledge of the spectrum of pathogens depending on the pathogenesis is indispensable for successful antibiotic therapy. Polymicrobial infections with a high proportion of anaerobes are found in conducted infections of the mediastinum and after esophageal perforation. After cardiac surgery Staphylococci are the dominant pathogens and a nasal colonization with Staphylococcus aureus seems to be a predisposing risk factor. Fungi are the predominant pathogens in immunocompromised patients with consumptive underlying illnesses and can cause acute or chronic forms with granulomatous inflammation. Resistant pathogens are increasingly being found in high-risk patient cohorts, which must be considered for a calculated therapy. For calculated antibiotic therapy the administration of broad spectrum antibiotics, mostly beta-lactams alone or combined with metronidazole is the therapy of choice for both Gram-positive and Gram-negative bacteria inclusive of anaerobes. For patients at risk, additional antibiotic classes with a spectrum against methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) can be administered. Increasing rates of multidrug-resistant Gram-negative bacteria (e.g. Enterobacteriaceae) and non-fermenting bacteria (e.g. Pseudomonas and Acinetobacter) in individual cases necessitates the use of polymyxins (e.g. colistin), new tetracyclines (e.g. glycylglycines) and newly developed combinations of beta-lactams and beta-lactam inhibitors. For treatment of fungal infections (e.g. Candida, Aspergillus and Histoplasma) established and novel azoles, amphotericin B and echinocandins seem to be successful; however, detection of Candida, particularly in mixed infections does not always necessitate treatment. Mediastinitis is still a severe infectious disease with a high mortality, which necessitates an early and broad spectrum antibiotic therapy; however, with respect to optimal duration of therapy and selection of antibiotics, data from good quality comparative studies are lacking.

Evaluation of Effectiveness and Safety of High-Dose Daptomycin: Results from Patients Included in the European Cubicin(®) Outcomes Registry and Experience

INTRODUCTION

Daptomycin, a rapid concentration-dependent bactericidal antibiotic, is approved at a dose of 4 mg/kg/day for the treatment of complicated skin and soft tissue infections (cSSTI) and at a dose of 6 mg/kg/day for the treatment of Staphylococcus aureus right-sided infective endocarditis (RIE) and bacteremia associated with cSSTI and RIE. Studies have reported the successful use of high-dose daptomycin (>6 mg/kg/day) in patients with difficult-to-treat infections. The present analysis evaluated the effectiveness and safety of high doses (>6 mg/kg/day) of daptomycin for the treatment of different Gram-positive infections.

METHODS

European Cubicin(®) Outcomes Registry and Experience (EU-CORE) is a non-interventional, multicenter, retrospective, patient registry designed to collect real-world data from patients treated with daptomycin between 2006 and 2012. Clinical outcomes were assessed at the end of daptomycin treatment for three dose groups: ≤6, >6 to <8, and ≥8 mg/kg/day. Safety was assessed for up to 30 days post-daptomycin treatment.

RESULTS

Of the 6075 patients enrolled in EU-CORE, 4892 patients received daptomycin doses ≤6 mg/kg/day, while 1097 patients received high doses (>6 mg/kg/day). The primary infections with the largest proportion of patients treated with a high dose (>6 mg/kg/day) were osteomyelitis (37.1%), foreign body/prosthetic infection (31.6%), and endocarditis (27.6%). S. aureus was identified in 42.9% of patients with positive cultures treated with either ≤6 or >6 mg/kg/day. The overall clinical success rate was 82.0% (899/1097) with high doses (>6 mg/kg/day) and 80.3% (3928/4890) with doses ≤6 mg/kg/day. Numerically higher clinical success rate was observed for endocarditis and foreign body/prosthetic infection, as well as for coagulase-negative staphylococcal and enterococcal infections, with high-dose daptomycin treatment. There were no new or unexpected safety findings at doses >6 mg/kg/day.

CONCLUSION

These results suggested that daptomycin at doses >6 mg/kg/day was effective and well tolerated. High-dose daptomycin is a potential therapeutic option in patients with difficult-to-treat Gram-positive infections.

FUNDING

This study was funded by Novartis Pharma AG.

Staphylococcus aureus and repeat bacteremia in febrile patients as early signs of sternal wound infection after cardiac surgery

BACKGROUND

Sternal wound infection is a devastating complication of cardiothoracic surgery that carries high postoperative morbidity and mortality rates. We explored whether our current program of extensive bacteriological examination including repeat blood cultures may contribute to the early diagnosis of sternal wound infection.

METHODS

We retrospectively analyzed 112 patients who were subjected to our bacteriological examination protocol including within 90 days after cardiothoracic surgery. Univariate and multivariate analyses were made in order to identify risk factors for sternal infection.

RESULTS

The median patient age was 75 years, and 65 patients were male. In 35 cases (31.2%) the blood cultures showed the presence of bacterial infection with the following frequencies: Staphylococcus aureus, 18 cases; Coagulase-negative Staphylococcus, 7 cases; other organisms, 10 cases. Eleven patients presented repeat bacteremia on at least 2 different occasions. Twenty patients (17.8%) presented sternal wound infections. There was no difference in operative mortality between the patients with and without sternal wound infection. Univariate and multivariate analyses demonstrated that bilateral mammary artery use (OR, 13.68, 95% CI, 1.09-167.36, p = 0.043), positive blood culture for Staphylococcus aureus (OR, 19.51, 95% CI, 4.46-104.33, p < 0.0001), repeat bacteremia (OR, 17.98, 95% CI, 2.51-161.77, p = 0.004) were risk factors that were associated for sternal wound infection.

CONCLUSION

Repeat blood cultures in febrile patients appear to be useful for the early detection of Staphylococcus aureus and repeat bacteremia, and these were associated with sternal wound infection. Bilateral internal mammary artery use was another risk factor of sternal wound infection in febrile patients. These factors may identify patients suitable for expeditious radiological examination and aggressive treatments.

Current use of daptomycin in cardiac surgery and postoperative intensive care

Infections due to multidrug-resistant pathogens have an increasing impact on patients undergoing cardiac surgery. Preoperative infections, such as endocarditis, and postoperative infections, including wound and device infection, influence patient outcomes. Special interest needs to be taken in patients admitted to cardiac surgical intensive care units, as these patients are at high risk for infections, particularly nosocomial pneumonia, catheter-related and wound infections. The increasing numbers of infections due to Gram-positive multidrug-resistant pathogens underline the necessity for newer antibiotics with bactericidal effects and a more favorable profile of side effects. Daptomycin, a lipopeptide antimicrobial agent with bactericide activity against Gram-positive organisms, has been successfully used in the treatment of complicated infections due to Gram-positive multidrug-resistant pathogens, especially regarding endocarditis, wound infections, device and catheter-related infections in intensive care units. In this review, the authors will summarize therapeutic potential of daptomycin in cardiac surgery and postoperative intensive care.

Midterm results after treatment of gram-positive deep sternal wound infections with daptomycin for cardiac surgery patients

Daptomycin in combination with surgical therapy has shown to be effective for treatment of deep sternal wound infection in cardiac surgery. However, till now midterm results in terms of re-infection or re-operation in patients who were successfully treated with daptomycin for gram-positive deep sternal wound infection are not published. Herein, we present midterm results in patients treated successfully with daptomycin after cardiac surgery.