Comparison of a Morphomic-Based to the Standard-of-Care-Based Cefazolin Dose for Antimicrobial Prophylaxis

Comparison of a Morphomic-Based to the Standard-of-Care-Based Cefazolin Dose for Antimicrobial Prophylaxis

The goal of this clinical study is to compare the dosing of an antibiotic in overweight patients having surgery. The main question[s] it aims to answer are:

• Are the antibiotic concentrations in blood and fat tissue in patients that are overweight sufficient to prevent the chance of infection?
• Can dosing using body composition rather than body weight improve the chance of achieving good antibiotic concentrations in overweight patients? Participants will allow us to collect small amounts of blood and fat tissue during their regularly scheduled surgery.

Researchers will compare differences in antibiotic concentrations based on dosing by standard of care (body weight based) versus body composition.

The risk of surgical site infections are higher in patients with obesity compared to non-obese adults. Our group has previously demonstrated that radiologic measures of abdominal subcutaneous fat are associated with surgical site infection risk in patients undergoing colorectal surgeries, which could reflect suboptimal antibiotic exposure in these patients. Therefore, we hypothesized that measures of abdominal size and composition in patients undergoing colorectal surgery would be more predictive of antimicrobial pharmacokinetics in this tissue compartment than the current standards of body weight and BMI. We confirmed this hypothesis and identified kidney function and body depth (by morphomics) to be predictive of cefazolin exposure in target tissue. Morphomics is a technology that transforms existing computed tomography data into body measures and composition. This study is a head-to-head comparison of this new proposed morphomic test regimen to the standard of care.

Inclusion Criteria:

1. Accessible abdominal computed tomography scan prior to surgery
2. Adult patients > 18 years of age
3. Body Mass Index ≥ 25 kg/m^2
4. Expected to receive cefazolin prior to surgical incision
5. Estimated creatinine clearance ≥90 mL/min

Exclusion Criteria:

1. History of a hypersensitivity reaction to penicillin or cephalosporin
2. Pregnancy