Bariatric Sleeve Gastrectomy, Cefazolin
Conditions
Keywords
Cefazolin, Ancef, Bariatric surgery, Sleeve, gastrectomy
Brief summary
This study investigates whether current cefazolin dosing guidelines for obese patients-2 g IV for those \<120 kg and 3 g IV for those ≥120 kg-achieve adequate plasma and tissue concentrations (≥8 mg/L) for effective surgical prophylaxis. While several retrospective and prospective studies suggest that a 2 g dose may be sufficient regardless of weight, findings are inconsistent and often rely solely on plasma concentrations. Given that tissue concentration at the site of action is a more relevant pharmacokinetic marker, the study emphasizes the need to measure cefazolin levels in adipose tissue. Previous research using microdialysis has shown reduced tissue distribution in obese patients, potentially warranting higher doses. The study also highlights variability in defining the minimum inhibitory concentration (MIC) required for prophylaxis, noting that 8 mg/L is often considered the threshold for Enterobacteriaceae. Ultimately, the study aims to clarify whether current dosing achieves effective antibiotic levels across different weight categories, with a focus on tissue concentrations.
Interventions
None listed
Sponsors
Fondation IUCPQ
Laval University
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Have a BMI ≥ 35 kg/m² * Undergo bariatric surgery (sleeve gastrectomy) via laparoscopy
Exclusion criteria
* Under 18 years of age * Weight over 180 kg * Penicillin allergy * Pregnant or breastfeeding women * Chronic kidney disease (eGFR \< 60 ml/min according to the Cockcroft-Gault equation) * Liver cirrhosis * Intraoperative blood loss ≥ 1 liter
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Area Under the Concentration-Time Curve (AUC) of Cefazolin in Plasma, Adipose Tissue, and Dermal Tissue | During surgery | AUC of cefazolin will be measured in plasma, adipose tissue, and dermal tissue at 0 minutes, 30 minutes, and at the end of surgery following administration according to current dosing guidelines. Unit of Measure: mg·min/L |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Proportion of Patients Achieving Cefazolin Plasma Concentrations ≥ 2 mg/L | During surgery | Proportion of patients with plasma concentrations of cefazolin ≥ 2 mg/L at each time point (0 min, 30 min, end of surgery), based on the MIC for methicillin-sensitive Staphylococcus aureus (MSSA). Unit of Measure: Percentage of patients (%) |
| Comparison of Cefazolin Concentrations Across Weight Categories | During surgery | Comparison of plasma and tissue concentrations of cefazolin across weight categories (\<120 kg, 120-149 kg, ≥150 kg) to identify potential underexposure in higher weight groups. Unit of Measure: Mean concentration (mg/L) |
| Proportion of Patients Achieving Cefazolin Tissue Concentrations ≥ 8 mg/L | During surgery | Proportion of patients with adipose and dermal tissue concentrations of cefazolin ≥ 8 mg/L at any time point (0 min, 30 min, end of surgery), based on the MIC for Enterobacteriaceae. Unit of Measure: Percentage of patients (%) |
| Tissue-to-Plasma Concentration Ratio of Cefazolin | During surgery | Ratio of cefazolin concentration in tissue to plasma at each time point to assess distribution efficiency. Unit of Measure: Ratio (unitless) |
| Time Above MIC (T>MIC) for Cefazolin in Plasma and Tissue | During surgery | Duration (in minutes) that cefazolin concentrations remain above MIC in plasma and tissue compartments, if additional time points are available. Unit of Measure: Minutes |
Other
| Measure | Time frame | Description |
|---|---|---|
| Screening and Eligibility Verification Through Demographic and Clinical Data | Preoperative period | Participants will be evaluated during preoperative consultation by a bariatric surgeon. If eligible, informed consent will be obtained. Demographic and clinical data will be collected to confirm inclusion criteria: * Height (cm) * Weight at recruitment (kg) * BMI at recruitment (kg/m²) * Allergy status to penicillin Blood samples will confirm: * Absence of liver cirrhosis * Absence of chronic kidney disease (eGFR \< 60 mL/min based on Cockcroft-Gault equation) |
| Demographic Data Collected Before Surgery for Eligibility Assessment | preoperative period | Prior to the start of surgery, demographic data will be collected to confirm participant eligibility according to inclusion criteria and establish baseline characteristics. Data collected: * Age (years) * Weight at admission (kg); will be used to determine the appropriate prophylactic dose of cefazolin. * Body Mass Index (BMI) at admission (kg/m²) |
Countries
Canada
Outcome results
None listed