Perioperative Cefazolin Prophylaxis in Pediatric Cardiac Surgery: A Prospective, Cohort Study

Background: This study's objective was to determine the effect of age, prolonged bypass, and hypothermia on serum cefazolin concentrations in children undergoing cardiac surgery.

Methods: A prospective, single-center, observational study was conducted, examining children undergoing cardiac surgery. Participants received cefazolin intravenously approximately 1 hour before skin incision, 3 hourly intraoperatively, and 8 hourly postoperatively. Blood samples were collected at 6 to 8 time points intraoperatively and at 6 time points in the first 24 hours postoperatively. Target unbound serum cefazolin concentrations were 2 mg/L.

Results: Sixty-eight patients were enrolled in the study, and 64 were included in the analysis. All maintained concentrations ≥ 2 mg/L throughout the operation. Nineteen patients (30%) did not maintain concentrations ≥ 2 mg/L in the first 24 hours after surgery. Older, larger children (P < .0001) were significantly less likely to achieve target unbound serum cefazolin concentrations.

Conclusions: Intraoperative cefazolin concentrations reached the target concentration in all pediatric cardiac surgical cases. Postoperative cefazolin dosing appears to be insufficient to achieve minimum inhibitory concentrations in many patients.