Case Study of Vancomycin Penetration into Brain Extracellular Fluid in Patients with Meningitis After Neurosurgery : The Abstracts

Abstract

Introduction: The efficacy of antimicrobials (AMs) depends on their capacity to achieve adequate concentration at the site of infection. The central nervous system (CNS) distribution of AMs is limited by the presence of the blood-brain barrier; therefore, plasma drug levels may not reflect brain extracellular fluid (ECF) levels which are considered the target site in case of meningitis. There is limited information about the pharmacokinetics (PK) after neurosurgical operation. We investigated CNS distribution of vancomycin (VAN) that is commonly used to treat neurosurgery-related bacterial meningitis caused by gram-positive pathogens. Objectives: To describe VAN penetration into brain ECF by microdialysis (MD) in patients with bacterial meningitis after neurosurgery. Methods: This was a case study of two patients diagnosed with postoperative bacterial meningitis and treated with VAN were included in the study. Both patients underwent routine monitoring using brain MD for determination of metabolism parameter concentrations. ECF, blood and CSF (where available) samples were collected simultaneously at steady state. The time points for sample collection were guided by the rate of MD microvials filling. To account for the inter-day variability samples were collected over one dosing interval on two consecutive days. VAN levels were determined by the turbidimetric inhibition immunoassay method. Results are provided in descriptive statistics. Results: The first patient was 28 years old male with congenital cerebral palsy, transverse myelitis at the conus medullaris level and epilepsy who underwent surgery for frontobasal encephalocele. Postoperative course was complicated by obstructive hydrocephalus (OH) and staphyloccocal meningitis. Since OH was managed by an external ventricular drain, VAN levels in CSF were also available for this patient. The second patientwas 69 years old male with chronic subdural haematoma [...].