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

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.

Study Overview

• Status: Completed
• Conditions: Surgical Prophylaxis
• Intervention / Treatment: Drug: Cefazolin for Injection

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 57
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • Michigan
    • Ann Arbor, Michigan, United States, 48108
      • University of Michigan Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Standard of Care; The patients assigned to this group have cefazolin dose assignments based on body weight, which is the standard of care.
Active Comparator: Morphomic-based; The patients assigned to this group have cefazolin dose assignments based on body depth and kidney function.	Drug: Cefazolin for Injection; 2 grams or 3 grams based on standard of care or morphomic-based decision

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of Concentration Target Attainment	Proportion of patients achieving at least 3.2 hours of time above 2 mcg/mL (MIC90) in subcutaneous fat tissue with the standard of care compared to morphomic-based dosing	4 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cefazolin exposure based on body depth	Compare the area under the curve from time 0 to 4 hours (AUC0-4) in plasma and subcutaneous fat in patients with a body depth above and below 350 mm	4 hours
Cefazolin exposure based on kidney function	Compare the area under the curve from time 0 to 4 hours (AUC0-4) in plasma and subcutaneous fat in patients with an estimated creatinine clearance above and below 120 mL/min	4 hours

Collaborators and Investigators

• Sponsor: University of Michigan
• Collaborators: Agency for Healthcare Research and Quality (AHRQ)

Study record dates

Study Major Dates

• Study Start (Actual): March 8, 2023
• Primary Completion (Actual): October 1, 2025
• Study Completion (Actual): October 1, 2025

Study Registration Dates

• First Submitted: August 16, 2023
• First Submitted That Met QC Criteria: August 16, 2023
• First Posted (Actual): August 22, 2023

Study Record Updates

• Last Update Posted (Actual): January 30, 2026
• Last Update Submitted That Met QC Criteria: January 28, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Obesity; Pharmacokinetics; Colorectal; Cefazolin; Surgical Prophylaxis; Morphomics
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Overweight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity; Sulfur Compounds; Organic Chemicals; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Therapeutics; Drug Administration Routes; Drug Therapy; Amides; beta-Lactams; Lactams; Cephalosporins; Thiazines; Cefazolin; Injections
• Other Study ID Numbers: HUM00222771; R01HS027183 (U.S. AHRQ Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No