Intraventricular vancomycin-induced cerebrospinal fluid eosinophilia: report of two patients.

Pediatric neurosurgeons commonly instill vancomycin into the ventricles to treat shunt infections. This use for vancomycin, however, has not been studied in the laboratory to evaluate possible toxicities and side effects. We report two cases of cerebrospinal fluid eosinophilia (CSFE) secondary to the intraventricular administration of vancomycin. Two other cases of shunt infection during the same time period were treated for only 2 days with intraventricular vancomycin and did not manifest CSFE. We address the clinical problems and possible detrimental effects of CSFE in the setting of shunt infection. We propose a mechanism of vancomycin-induced mast cell degranulation and subsequent release of eosinophil chemotactic factor as a cause of CSFE. An initial dose of intraventricular vancomycin should take into account volume of distribution (ventricular size) to obtain a peak cerebrospinal fluid concentration of 20 to 30 micrograms/mL. We recommend following daily cell counts and vancomycin peak and trough levels to calculate the amount and frequency of intraventricular vancomycin required to maintain safe and effective concentrations and to monitor for CSFE.