Antibiotic prophylaxis is essential for all types of cardiac surgery under Extracorporeal Circulation (ECC), in order to reduce the incidence of surgical site infection (SSI). However, many patients are allergic to beta-lactam antibiotics. All the more, vancomycin antibiotic recommended as replacement is not without adverse effects and frequently administered in an inappropriate manner in terms of pre-intervention timing, linked to its complex use on peripheral venous lines complicated by venotoxicity. Non-compliance with the correct use of antibiotic prophylaxis in surgery is responsible for nosocomial infections, which have an impact on both the patient and the healthcare establishment in terms of costs, particularly in cardiac surgery. Drug pharmacokinetics are more complex under bypass surgery (high volume of distribution), and studies are needed to determine the correct administration and diffusion of drugs. In this respect, clindamycin is an antibiotic already used in antibiotic prophylaxis for other surgeries (thoracic, orthopedic...) in cases of allergy to beta-lactam antibiotics, but to date there are no studies examining the pharmacokinetics of this molecule in the context of cardiac surgery under ECC. The aim of this protocol is to demonstrate the feasibility of using clindamycin in patients undergoing ECC surgery, by verifying that the plasma concentration of clindamycin exceeds the minimum inhibition concentration (MIC) of the main bacteria involved in mediastinitis throughout the surgical procedure.
ECC is indispensable for cardiac surgery, but this assistance modifies the pharmacological properties of drugs, with a particular increase in the volume of distribution of antibiotics such as clindamycin. All these factors lead to an increase in the dosage of certain drugs and more frequent injections. Robust data on percutaneous clindamycin treatment would therefore enable to improve the management of this type of patient, with real impact. There are currently no pharmacological studies justifying the use of clindamycin to combat nosocomial infections in cardiac surgery, despite the fact that its anti-bacterial spectrum is identical to that of the antibiotics currently used in patients (methicillin-sensitive Staphylococcus aureus (MSSA)). Clindamycin is simpler to use and does not induce venotoxicity. The fact that the patient is undergoing bypass surgery means that pharmacokinetic studies can be carried out with several blood samples taken from the arterial pressure catheter routinely inserted in all surgical patients, in order to limit the volume of blood taken and avoid any discomfort for the patient. This would make it possible to check the plasma stability of this antibiotic over several periods, with reinjections if necessary (if surgery \> 4h). The hypotheses are that clindamycin (i) is simple to use, (ii) has correct and stable diffusion kinetics in patients undergoing scheduled cardiac surgery with ECC (iii) is well tolerated by patients (iv) has an estimated free plasma concentration above the epidemiological threshold Minimal Inhibition Concentration (MIC) of Staphylococcus aureus and therefore provides sufficient protection against SSI.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
PREVENTION
Masking
NONE
Enrollment
25
Clindamycin used in the study corresponds to commercial forms of injectable clindamycin : KBI 600 mg/4 mL injectable solution, ampoule. * 1 ampoule contains 600 mg Clindamycin phosphate (expressed as Clindamycin base). * Excipients: edetate disodium, benzyl alcohol, sodium hydroxide, water for injection. * Dosage form: injectable solution 10minutes after injecting the first bolus of cefuroxime, clindamycin is reconstituted in 50 mL of 0.9% NaCl, then 900 mg of clindamycin is administered as a slow IV over 30 minutes. At H+4 from the end of the clindamycin injection, if skin closure is not effective, clindamycin at a dose of 600 mg in 50 mL 0.9% NaCl is re-injected over 20 minutes.
CHU Nantes
Nantes, France, France
Plasma clindamycin concentrations
To demonstrate the feasibility of using clindamycin in patients undergoing ECC and to assure that plasma clindamycin concentrations remain above the minimum inhibition concentration (MIC) of the main bacteria involved in mediastinitis, estimated free plasma clindamycin concentration will be verify throughout surgery. The free plasma concentration of clindamycin is estimated by measuring the total plasma concentration of clindamycin, based on a bound fraction of 80 to 94%.The epidemiological threshold MIC for S. aureus (ECOFF = 0.25 mg/L for clindamycin) was chosen for comparison with clindamycin concentrations, given that this bacterium is the main one implicated in mediastinitis.
Time frame: H0 (at incision), then every hour, and at the end of surgery (defined as sternal closure)
Determine the pharmacokinetic parameters of clindamycin under ECC
Volume of distribution, clearance, elimination half-life, quantity of intra-operative vascular filling (in ml) including blood transfusions: number and type of intra-operative LBS (labile blood products)
Time frame: At H0 (at incision), then every hour, and at the end of surgery (defined as sternal closure)
Determine the factors of variability in clindamycin pharmacokinetics for patients under ECC surgery
Collection of weight, height (calculation of BMI), collection of usual post-CEC biological data (creatinemia with calculation of GFR, ASAT/ALAT, total and conjugated bilirubinemia, PAL, γ-GT, protidemia with addition of α-1 acid glycoprotein at induction), qualitative record of CYP3A4/5 inducer/inhibitor drugs, CEC modalities (duration, type and quantity of priming solution, type of cardioplegia, body temperature), blood transfusion and volume reprocessed by Cell-Saver©.
Time frame: Post-ECC at H+6 and H+24
Determining the diffusion of clindamycin in pericardial fatty tissue
Tissue determination of clindamycin in pericardial fat and correlation with plasma levels (biocollection, ancillary study
Time frame: At the start of the operation (sternotomy) and when the pericardium is closed
Description of adverse events according to NCI CTCAE V5 criteria
Recording of AEs and SAEs, collection of all clinical signs indicative of anaphylaxis on medical examination
Time frame: From first injection of clindamycin to end of hospitalization
Adherence to Good Clinical Practice clindamycin injection protocol
Recording of clindamycin injection duration, time of reinjections and duration of reinjections, calculation of delta between time of end of clindamycin injection and start of surgical incision
Time frame: From first injection of clindamycin to the end of surgery (defined as sternal closure)
Rate of post-operative mediastinitis (up to 3 months post-operatively)
Rate of post-operative mediastinitis defined as a post-operative nosocomial cardiac surgery infection at the surgical site (mediastinum) requiring repeat surgery (drainage lavage) and prolonged antibiotic therapy. Collection of data from the patient's file, as the patient was systematically referred to the Nantes University Hospital. Collection of bacterial ecology
Time frame: From inclusion to 3 months post-operatively (M3)
Post-op morbidity and mortality
Mortality at 3 months (telephone call)
Time frame: At 3 months (M3) post-operative (follow-up)
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