Pharmacokinetics of Preoperative Vancomycin

Background: Vancomycin is used for antibiotic prophylaxis in pediatric surgical patients
without a complete understanding of plasma and soft tissue pharmacokinetics. Guidelines
recommend incision within 60 minutes after administration; however, tissue concentrations of
vancomycin at that early time may not be therapeutic. The Investigators conducted a study of
plasma and tissue concentrations in pediatric neurosurgical and orthopedic patients to
characterize intraoperative vancomycin pharmacokinetics.

Patients, ages (0.1-18.8 years), undergoing posterior spinal fusion (n=30) or
ventriculoperitoneal shunt placement (n=30), received intravenous vancomycin 15 mg/kg over
one hour. Skin biopsies were taken at incision and skin closure. Blood samples were also
collected at incision and closure; additional samples were drawn at 2- and 4-hours if patient
was still in surgery. Population pharmacokinetic (PK) analysis was performed to characterize
PK parameter estimates and to develop a model of intraoperative plasma and tissue vancomycin
concentrations vs. time.

Inclusion Criteria:

1. Neurosurgery patients between the ages of 31 days up to 18 years

2. Receiving a single dose of vancomycin administered prior to surgery for cerebrospinal
fluid (CSF) shunt placement or revision.

3. Orthopedic surgical patients between the ages of 31 days up to 18 years

4. Receiving a single dose of vancomycin administered prior to surgery for definitive
spinal fusion.

Exclusion Criteria:

1. Patients already receiving vancomycin for treatment of an active infection,

2. Patients who have a Creatinine ≥1.2,

3. Patients who's creatinine clearance less than 50,

4. Known chronic renal failure and are on dialysis,

5. Patients with a known allergy to vancomycin, not including Red Man Syndrome.