Conditions: Late Effects of Surgery Staphylococcus Aureus Surgical Site Infection
Keywords: Daptomycin Antibiotic Prophylaxis Pharmacokinetics Surgical Wound Infection Staphylococcus aureus Cardiopulmonary Bypass Surgery
Allocation: NON_RANDOMIZED | Intervention model: SINGLE_GROUP
Enrollment: 30
Healthy volunteers: no

Brief summary:
This investigation is a prospective, open-label pharmacokinetic study of daptomycin prophylaxis in patients undergoing coronary artery bypass graft surgery without valvular replacement.

Detailed description:
Cardiothoracic surgery is a commonly performed procedure in the United States. Many sites previously used cefazolin, an antibiotic, as standard prophylaxis to prevent surgical site infections. However, given most bacteria causing surgical site infections are now resistant to cefazolin, most center are using vancomycin, an alternative antibiotic, as surgical antibiotic prophylaxis. However, some patients cannot take vancomycin, and there are no well studied alternatives to vancomycin for surgical prophylaxis. Therefore, we are studying daptomycin, a newer United States Food and Drug Administration (FDA)-approved antibiotic, as prophylaxis against surgical site infections among patients undergoing cardiothoracic bypass (CPB) with coronary artery bypass graft surgery (CABG). Our study will not be powered to see if daptomycin is as effective as vancomycin at preventing surgical site infections. Instead, the purpose of this study is to validate that adequate levels of antibiotics are present in patients' blood during cardiothoracic bypass surgery.

Study subjects in the intervention group will be followed from the time of enrollment in the study until their discharge from the hospital, or up to 7 days following administration of daptomycin, whichever comes first.

The first 15 subjects enrolled will receive the intervention drug daptomycin as surgical antibiotic prophylaxis and the following 15 subjects will be enrolled as matched controls and will receive the standard of care surgical prophylaxis per the patient's treating physicians. The controls will undergo monitoring for the same safety outcomes that the patients who received daptomycin will undergo.

Subjects enrolled in the intervention group will receive a single intravenous administration of daptomycin 8 milligram (mg)/kilogram (kg) 30-60 minutes prior to surgery (incision). Blood samples will be drawn by the Research Coordinator. A total of 85 (milliliters) mL of blood will be collected during the study. A total of 14 blood samples will be collected: 4 samples at the Pre-CPB phase, 4 samples during the CPB procedure, and 6 samples Post-CPB. Total plasma daptomycin concentrations will be determined utilizing standard high-performance liquid chromatography techniques. Plasma concentrations will be compared to the minimum inhibitory concentrations (MIC90) of the common pathogens involved in surgical site infections, specifically Staphylococcus aureus and coagulase negative Staphylococcus.

Arms:
arm 1: The first 15 subjects enrolled will receive the intervention drug daptomycin as surgical antibiotic prophylaxis. arm 2: 15 subjects will be enrolled in the standard of care antibiotic group to serve as the controls. Controls will receive no experimental medications or treatments. The purpose of enrolling control patients was to serve as a reference group for intervention patients. Specifically cases and controls will be compared for changes in commonly collected hematologic parameters, creatinine, and CPK. Additionally, parameters collected during anesthesia will be compared. Controls will be matched to the intervention group by age (+/- 10 years), gender, and ethnicity.

Interventions: intervention 1: daptomycin
Intervention descriptions: intervention 1: Subjects enrolled in the intervention group will receive a single intravenous administration of daptomycin 8 mg/kg 30-60 minutes prior to surgery (incision). The 500 mg vial will be reconstituted with 10 mL of 0.9% normal saline (NS) and further diluted in 50 mL of 0.9% NS to be given over a 30 minute infusion.

Protocol document: