Obesity and Antibiotic Tissue Concentration

October 7, 2010 updated by: MemorialCare

Effects of Maternal Obesity on Tissue Concentrations of Prophylactic Antibiotics During Cesarean Delivery

The purpose of this study is to determine whether the dose of prophylactic antibiotics at the time of cesarean delivery requires adjustment in obese and overweight patients in order to achieve optimal antimicrobial activity.

Study Overview

Status

Completed

Conditions

Detailed Description

The majority of information regarding pharmacokinetics and pharmacodynamics (the action, properties and elimination of a drug in the body) of antibiotics is based on measurements of the serum and plasma concentrations. Current guidelines for surgical antibiotic prophylaxis have clearly demonstrated appropriate therapeutic levels within blood and serum levels, resulting in low incidence of postoperative bacteremia (bacteria in the blood) and sepsis (infection). Despite this, surgical site infections (SSI) remain the most common postoperative complication, affecting up to 20% of patients undergoing intra-abdominal surgery. Inadequate antibiotic penetration into the tissues of the surgical site, in spite of therapeutic serum levels, results in an environment that is susceptible to pathogens and subsequent infections. Antimicrobial tissue levels are influenced by volume of distribution, regional blood flow and biological properties of tissue. The ability of any drug to reach the tissue of interest is dictated by the relative amount of blood flow to that organ. While lungs and kidneys enjoy a robust blood supply, subcutaneous adipose tissue (fat) (the most frequent site of surgical site infections) receives a small fraction of the cardiac output. Obesity creates an increased volume of distribution, thereby resulting in a greater dilution of antibiotics when compared to non-obese subjects. Moreover, this change in volume of distribution is achieved primarily by increasing the relative amount of poorly perfused adipose tissue. Therefore, it should come as no surprise that obesity is a significant risk factor for surgical site infections.

The rate of obesity in the United States has shown a steady increase and more than doubled in the last twenty-five years from 15% in 1980 to 32.9% in 2004. Moreover, nearly one third of women of reproductive age are obese and approximately 6% are extremely obese. In addition to the usual health related concerns, obesity significantly increases the rate of complications associated with pregnancy. In particular, several studies have demonstrated an increased incidence of cesarean delivery associated to maternal obesity. Cesarean delivery rates, much like obesity rates, have witnessed a tremendous surge in the last few decades and now account for approximately 30% of all deliveries or nearly 1.2 million procedures. Surgical site infections associated with cesarean delivery include wound infections and endomyometritis (infection in the uterus), with rates ranging from 7% to 20% depending on the demographic and obstetric variables. Despite these alarming trends there is a paucity of data regarding antimicrobial activity of prophylactic antibiotics in tissues and the effects of maternal obesity on these concentrations at the time of cesarean delivery.

While the rates of cesarean deliveries have reached a plateau at around 30% in recent years, the rates of obesity continue to climb unabated. As the attributes of the population evolve over the course of time so must the guidelines and management adapt to the individuals in our care.

Study Type

Observational

Enrollment (Actual)

31

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Long Beach, California, United States, 90806
        • Women's Pavilion at Miller Children's Hospital
      • Orange, California, United States, 92868
        • University of California Irvine Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Female

Sampling Method

Non-Probability Sample

Study Population

All patients requiring cesarean delivery under non-emergent circumstances

Description

Inclusion Criteria:

  • Patients at term (> 37 weeks) undergoing a cesarean delivery.

Exclusion Criteria:

  • Women younger than 18 years,
  • Pre-gestational diabetes,
  • Chronic hypertension,
  • Collagen vascular disease,
  • Multiple gestation,
  • Contraindications to cefazolin administration (known anaphylactic reaction to penicillins or known cephalosporin allergy),
  • Any exposure to cephalosporins in one week prior to cesarean section, OR
  • Need for emergent cesarean delivery or diagnosis of chorioamnionitis.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
BMI <30
BMI 30-39
BMI >40

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
To assess the effects of maternal obesity on the concentrations and adequacy of antimicrobial activity of prophylactically administered antibiotics within tissues (subcutaneous adipose and myometrial) at the time of cesarean delivery.
Time Frame: 6 weeks
6 weeks

Secondary Outcome Measures

Outcome Measure
Time Frame
To assess the concentrations and adequacy of antimicrobial activity of prophylactically administered antibiotics within tissues (subcutaneous adipose and myometrial) at the time of cesarean delivery.
Time Frame: 6 weeks
6 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

MemorialCare

Collaborators

University of California, Irvine

Investigators

  • Principal Investigator: Kenneth Chan, MD, Long Beach Memorial Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

June 1, 2009

Primary Completion (Actual)

June 1, 2010

Study Completion (Actual)

June 1, 2010

Study Registration Dates

First Submitted

September 18, 2009

First Submitted That Met QC Criteria

September 18, 2009

First Posted (Estimate)

September 21, 2009

Study Record Updates

Last Update Posted (Estimate)

October 8, 2010

Last Update Submitted That Met QC Criteria

October 7, 2010

Last Verified

September 1, 2010

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 587-08

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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