# CSF Device Management -- IDSA 2017

## General Principle

Removal of the infected device is a critical component of treatment for healthcare-associated ventriculitis and meningitis. Medical therapy alone without device removal is associated with higher treatment failure rates.

## Device Removal Recommendations

### CSF Shunts

- Infected CSF shunts should be **removed** and replaced with an **external ventricular drain (EVD)** to allow continued CSF diversion, intraventricular antimicrobial administration, and monitoring of CSF cultures (Strong, Moderate).
- **Do not attempt** to treat shunt infections with systemic antibiotics alone without shunt removal (Strong, Moderate).

### External CSF Drains (EVDs, Lumbar Drains)

- Infected external CSF drains should be **removed** (Strong, Moderate).
- A new external drain may be placed at a different anatomical site if continued CSF drainage is clinically necessary (Strong, Moderate).

### Intrathecal Infusion Pumps

- Infected intrathecal infusion pumps should be **removed** (Strong, Moderate).

### Deep Brain Stimulation (DBS) Hardware

- Infected deep brain stimulation hardware should be **removed** (Strong, Moderate).

## Device Removal Decision Algorithm

```
Confirmed or strongly suspected healthcare-associated ventriculitis/meningitis
  --> Is an indwelling CSF device present?
      --> YES:
          --> Remove the infected device (Strong, Moderate)
          --> Place new EVD at a different site if continued CSF drainage is needed
          --> Begin systemic antimicrobial therapy
          --> Consider intraventricular antimicrobial therapy if indicated
          --> Monitor CSF cultures via the new EVD
      --> NO (post-neurosurgical or post-traumatic meningitis):
          --> Systemic antimicrobial therapy
          --> Consider EVD placement for CSF sampling and/or intraventricular therapy
          --> Source control of wound infection if present
```

## Shunt Reimplantation Timing

Timing of new CSF shunt reimplantation depends on the causative organism, CSF culture sterilization, and CSF biochemical normalization.

### Coagulase-Negative Staphylococci or *P. acnes*

- **If no significant CSF abnormalities** (minimal pleocytosis, normal glucose) and **48 hours of negative CSF cultures**: reimplant as early as **day 3** after shunt removal (Strong, Low).
- **If significant CSF abnormalities** (marked pleocytosis, hypoglycorrhachia) with **negative repeat CSF cultures**: reimplant on **day 7** of antimicrobial therapy (Strong, Low).
- **If repeat CSF cultures remain positive**: continue therapy and reimplant after **7-10 consecutive days of negative CSF cultures** (Strong, Low).

### *Staphylococcus aureus* or Gram-Negative Bacilli

- Reimplant on **day 10** after CSF cultures become negative (Strong, Low).

### Decision Algorithm for Shunt Reimplantation

```
CSF shunt removed for infection
  --> Identify causative organism
      --> Coagulase-negative staph or P. acnes:
          --> CSF normal (minimal pleocytosis, normal glucose)?
              --> YES + 48h negative cultures --> Reimplant day 3
              --> NO (significant CSF abnormalities):
                  --> Repeat cultures negative --> Reimplant day 7
                  --> Repeat cultures still positive:
                      --> Continue antibiotics
                      --> Reimplant after 7-10 consecutive negative culture days
      --> S. aureus or gram-negative bacilli:
          --> Continue antibiotics + CSF culture monitoring
          --> Reimplant day 10 after cultures become negative
  --> CRITICAL: Do NOT discontinue antimicrobial therapy before reimplantation
     to "verify" CSF clearing (Strong, Low)
```

### Critical Principle: Do Not Interrupt Therapy

- **Do NOT discontinue antimicrobial therapy prior to reimplantation** to verify CSF clearing (Strong, Low).
  - Interrupting therapy risks relapse of infection and loss of microbiological control.
  - Continue full-dose antimicrobial therapy through the reimplantation procedure and for the full intended treatment duration.

## Post-Reimplantation Monitoring

- After shunt reimplantation, complete the full course of antimicrobial therapy as determined by the pathogen and clinical response.
- Clinical monitoring for signs of recurrent infection should continue after completion of therapy.
- There is no guideline-specified duration for post-treatment surveillance; clinical judgment should guide follow-up.

## Treatment Monitoring During External Ventricular Drainage

### CSF Culture Monitoring

- For patients with external ventricular drains, CSF cultures should be monitored to document culture sterilization (Strong, Low).
- If the patient is not improving clinically, repeat CSF analysis (cell count, glucose, protein) should be performed to assess biochemical response (Strong, Low).
- **Daily CSF cultures and analysis are NOT required** in patients who are improving clinically (Strong, Low).
  - Reserve repeat sampling for patients with clinical deterioration, persistent fever, or other signs of treatment failure.

### When to Suspect Treatment Failure

- Persistent positive CSF cultures after >=48 hours of appropriate therapy.
- Worsening CSF pleocytosis or declining CSF glucose despite antimicrobial therapy.
- Clinical deterioration (worsening mental status, new focal deficits, hemodynamic instability).
- **Action:** Review antimicrobial adequacy (spectrum, dose, route), consider adding intraventricular therapy, reassess device status, and obtain repeat imaging.

## Limitations

- Shunt reimplantation timing is based on expert consensus and limited observational data (low quality evidence).
- Optimal management of patients who cannot tolerate shunt removal (e.g., complete shunt dependence with no alternative CSF diversion) is not well addressed.
- The guideline does not provide specific recommendations for endoscopic third ventriculostomy as an alternative to shunt reimplantation.
