Related Experiment Video
Updated: Jan 12, 2026
Multiplex Therapeutic Drug Monitoring by Isotope-dilution HPLC-MS/MS of Antibiotics in Critical Illnesses
Published on: August 30, 2018
Population pharmacokinetics of cefazolin administered as prophylaxis in paediatric patients undergoing cardiac
Vesa Cheng1, Jessica Suna2, Xin Liu3
1University of Queensland Centre of Clinical Research, The University of Queensland, Brisbane, Australia; Medical Education Unit, Princess Alexandra Hospital, Metro South Health, Brisbane, Australia.
Insights
Postoperative cefazolin dosing in children undergoing heart surgery is often too low, risking infection. Increasing dose frequency or using continuous infusions can improve effectiveness and patient safety.
Area of Science:
- Pharmacology
- Pediatric Critical Care
- Cardiovascular Surgery
Background:
- Optimizing antimicrobial prophylaxis is crucial for pediatric patients undergoing cardiac surgery with cardiopulmonary bypass.
- Cefazolin pharmacokinetics require specific investigation in this high-risk pediatric population.
Purpose of the Study:
- To characterize cefazolin pharmacokinetics in pediatric patients during cardiac surgery.
- To determine optimal cefazolin dosing regimens for effective antimicrobial prophylaxis.
Main Methods:
- Prospective, single-center observational study involving 68 pediatric patients.
- Intravenous cefazolin administration with serial blood sampling for unbound concentration measurement.
- Population pharmacokinetic modeling and dosing simulations to assess target attainment (fT>MIC).
Main Results:
- Conventional cefazolin regimens led to subtherapeutic concentrations in up to 16.8% of patients postoperatively.
- Target attainment decreased with increasing estimated glomerular filtration rate (eGFR).
- Simulations showed increased postoperative dosing (25 mg/kg every 3 hours) or extended/continuous infusions achieved target concentrations for all patients.
Conclusions:
- Current postoperative cefazolin dosing is frequently inadequate in pediatric cardiac surgery patients.
- More frequent dosing or alternative infusion strategies are necessary for optimal antimicrobial prophylaxis.
- Improved cefazolin dosing may reduce surgical site infection risk in this vulnerable group.
Introduction:
This study describes cefazolin pharmacokinetics in paediatric patients undergoing cardiac surgery using cardiopulmonary bypass to optimise antimicrobial prophylaxis.
Methods:
A prospective, single-centre, observational study was conducted to describe cefazolin pharmacokinetics in paediatric patients undergoing cardiac surgery. Cefazolin was administered intravenously before skin incision, every three hours intraoperatively, and every eight hours postoperatively. Blood samples were collected on 6-8 occasions intraoperatively and six postoperatively, depending on re-dosing. Unbound cefazolin concentrations were measured using a chromatographic assay and analysed using a population pharmacokinetic approach in Monolix®. Dosing simulations were performed to determine the optimal regimen to maintain unbound cefazolin concentrations above the minimum inhibitory concentration for 100% of the dosing interval (fT>MIC) in both intraoperative and postoperative phases.
Results:
Sixty-eight patients were recruited and included in the pharmacokinetic model. Conventional cefazolin dosing regimens (preoperative 50 mg/kg, intraoperative 25 mg/kg 3-hourly and postoperative 25 mg/kg 8-hourly) resulted in subtherapeutic concentrations in up to 16.8% of paediatric patients postoperatively in cardiac surgery requiring cardiopulmonary bypass. Target attainment decreased with increasing eGFR. Dosing simulations indicated that increasing the postoperative dose to 25 mg/kg 3-hourly or using extended and continuous infusions achieves target attainment for all groups.
Discussion:
Postoperative cefazolin concentrations in paediatric patients undergoing cardiopulmonary bypass are often inadequate to maintain optimal antimicrobial prophylaxis. More frequent postoperative dosing or the use of extended and continuous infusion strategies can ensure effective target attainment, potentially reducing the risk of surgical site infections in this vulnerable population.
More Related Videos
09:17A Robust Pneumonia Model in Immunocompetent Rodents to Evaluate Antibacterial Efficacy against S. pneumoniae, H. influenzae, K. pneumoniae, P. aeruginosa or A. baumannii
Published on: January 2, 2017
09:26Antibiotic Efficacy Testing in an Ex vivo Model of Pseudomonas aeruginosa and Staphylococcus aureus Biofilms in the Cystic Fibrosis Lung
Published on: January 22, 2021
Related Concept Videos
01:22Pharmaceutical Alternatives: Stability-Related Therapeutic Nonequivalence
01:17Pharmacokinetics in Pediatric Patients: Drug Distribution
01:23Pharmacokinetics in Pediatric Patients: Overview and Drug Absorption
01:26Pharmacokinetics in Pediatric Patients: Drug Excretion
01:15Determination of Multiple Dosing Parameters: Steady-State, Minimum and Maximum Concentrations
01:24Pharmacokinetics in Pediatric Patients: Drug Metabolism