Infection in a functioning ventriculoperitoneal shunt treated with intraventricular gentamicin.

A case of successful treatment of a functioning ventriculoperitoneal (VP) shunt infection with high doses of intraventricular gentamicin sulfate is reported. The VP shunt reservoir of a four-month-old girl with hydrocephalus became infected. The scalp wound was debrided and intravenous methicillin sodium, 200 mg every six hours, was administered. When culture and sensitivity tests later showed Enterobacter cloacae, methicillin was discontinued. Intraventricular gentamicin, 2 mg/day, and intravenous carbenicillin, 400 mg/kg/day, were administered. Gentamicin dosage was increased twice over the next eight days to 6 mg/day. The trough cerebrospinal fluid (CSF) gentamicin level at 2 mg/day was 1.7 micrograms/ml, at 4 mg/day was 0.7 microgram/ml and at 6 mg/day was 19.6 micrograms/ml. Gentamicin was discontinued after 14 days; carbenicillin was continued for 7 more days. For a second shunt infection with Klebsiella pneumoniae, intraventricular gentamicin and intravenous chloramphenicol were given for 21 days. Previous reports of ventricular shunt infections are reviewed. The report indicates that it is possible to achieve therapeutic CSF levels of gentamicin in patients with patent VP shunts by administering 2--5 times (depending on ventricle size) the usual intraventricular dose.