# Effective Treatment of Acinetobacter baumannii Ventriculitis With Interventricular Colistin: A Case Report

## TL;DR

A patient with a brain infection caused by drug-resistant bacteria improved significantly after receiving colistin directly into the brain's ventricles.

## Contribution

Demonstrates the effectiveness of intraventricular colistin in treating Acinetobacter baumannii ventriculitis.

## Key findings

- Intraventricular colistin improved neurological condition and reduced inflammation in a patient with Acinetobacter ventriculitis.
- Intravenous colistin alone showed limited effectiveness compared to intraventricular administration.
- The patient recovered sufficiently to be discharged despite multiple complications.

## Abstract

Cerebrospinal fluid shunts are the primary treatment for hydrocephalus. However, prolonged external ventricular drain (EVD) use can lead to central nervous system (CNS) infections such as ventriculitis. In the ICU setting, nosocomial infections with gram-negative, multi-drug resistant (MDR) organisms such as Acinetobacter baumannii (AB) prevail, leading to poor outcomes. AB infections are notably challenging due to their genetic drug resistance. Colistin has been reintroduced for use against gram-negative MDR pathogens but has limitations in CNS penetration when administered intravenously. Therefore, intraventricular (IVT) or intrathecal administration of colistin is recommended to enhance its therapeutic reach within the CNS.

We present a case of a 22-year-old male admitted after an electric scooter accident with head trauma and hydrocephalus. A ventriculoperitoneal (VP) shunt was inserted, complicated by a nosocomial neuroinfection. Empiric IV therapy with meropenem and vancomycin was initiated. The VP shunt culture identified AB susceptible only to colistin. Intravenous (IV) colistin was added to meropenem with no significant improvement. The addition of IVT colistin significantly improved the patient's neurological condition and reduced inflammatory markers. The patient experienced one myoclonic seizure during IVT colistin treatment, managed with antiepileptics. After multiple unrelated nosocomial complications, the patient was discharged in good condition to rehabilitation.

This case suggests that IVT colistin, combined with IV administration, may be preferable over IV colistin alone. Medical staff should be informed about the correct prevention and care of EVD-associated infections.