What is the management of meningoencephalitis with raised Intracranial Pressure (ICP)?

Management of Meningoencephalitis with Raised Intracranial Pressure

The cornerstone of managing meningoencephalitis with elevated ICP is aggressive CSF drainage through serial lumbar punctures to reduce opening pressure to ≤20 cm CSF, combined with immediate empiric antimicrobial therapy and avoidance of acetazolamide and corticosteroids for ICP control. 1, 2

Immediate Actions Upon Presentation

Antimicrobial Therapy

• Obtain blood cultures immediately, then start empiric antimicrobials without delay—even before lumbar puncture if imaging or LP will be delayed. 2
• Delay in antimicrobial initiation significantly increases morbidity and mortality. 2
• For cryptococcal meningoencephalitis specifically: Amphotericin B deoxycholate (0.7-1.0 mg/kg/day IV) plus flucytosine (100 mg/kg/day orally in 4 divided doses) for at least 2 weeks. 1, 2

Diagnostic Lumbar Puncture Timing

• Perform LP immediately to measure opening pressure and obtain CSF for analysis unless focal neurologic signs, impaired mentation, or papilledema are present. 1, 2
• If contraindications exist, obtain CT or MRI first to rule out mass lesions or obstructive hydrocephalus that increase herniation risk. 1, 2
• Clinical assessment, not CT imaging, should determine LP safety—CT is not reliable for diagnosing raised ICP. 1

Aggressive ICP Management Protocol

Baseline Pressure Measurement

• Measure opening pressure at baseline LP—this is critical as elevated ICP (≥25 cm CSF) is present in approximately 50% of patients and correlates with early mortality. 1, 2
• Patients who died within the first 2 weeks had baseline ICP ≥25 cm CSF in 11 of 12 cases. 2
• Failure to measure and manage elevated CSF pressure results in new neurologic abnormalities in 50% of patients versus 8% when guidelines are followed. 2

Therapeutic Lumbar Puncture Protocol

• If CSF pressure is >25 cm CSF with symptoms of increased ICP, perform therapeutic LP to reduce opening pressure by 50% if extremely high, or to normal pressure of 20 cm CSF. 1, 2
• For persistent pressure elevation >25 cm CSF with symptoms, repeat LP daily until ICP and symptoms stabilize for >2 days. 1, 2
• This aggressive drainage approach is associated with increased survival. 2, 3

Advanced Drainage Options

• Consider temporary percutaneous lumbar drains for patients requiring repeated daily LPs—these can be safely maintained for up to 13 days with bacterial superinfection risk <5%. 2, 4
• Ventriculostomy should be considered for patients with obstructive hydrocephalus or when LP is contraindicated. 2, 4
• Ventricular access devices (VADs) are preferred over external ventricular drains as they reduce morbidity and mortality. 4
• Permanent ventriculoperitoneal shunts should only be placed after appropriate antifungal therapy has been initiated and conservative measures have failed, but can be placed during active infection if clinically necessary. 1, 2, 3

Critical Medications to AVOID for ICP Management

Acetazolamide

• Do NOT use acetazolamide—a randomized trial was stopped prematurely due to severe metabolic acidosis and complications. 1, 2, 4
• Level I evidence shows it does not reduce shunt need and may increase death and neurological morbidity. 4

Corticosteroids

• Do NOT use high-dose corticosteroids for ICP elevation—mortality and clinical deterioration were observed more commonly in corticosteroid recipients. 1, 2
• Exception: Corticosteroids may be used as part of IRIS treatment or for persisting hypotensive shock (hydrocortisone 200 mg daily). 1

Mannitol

• Mannitol has no proven benefit and is not routinely recommended for ICP management in meningoencephalitis. 1
• While mannitol reduces ICP in other neurological conditions by osmotic diuresis, it lacks evidence in meningoencephalitis. 5, 6

Supportive Critical Care Management

Hemodynamic Support

• Maintain euvolemia with crystalloids as initial fluid of choice to achieve normal hemodynamic parameters. 1, 2
• Target mean arterial pressure (MAP) ≥65 mmHg, though this may need individualization: younger patients with significant shock may tolerate MAP 50-60 mmHg, while older patients with cerebral edema may require MAP 70 mmHg for adequate cerebral perfusion pressure. 1
• Use norepinephrine as the initial vasopressor for hypotension after euvolemia is restored—it has equivalent efficacy to dopamine but fewer adverse events. 1, 2
• Albumin should be considered in patients with persistent hypotensive shock despite corrective measures. 1

Fluid Management Principles

• Keep patients euvolaemic—fluid restriction to reduce cerebral edema is not recommended. 1
• Over-vigorous fluid administration may exacerbate cerebral edema, but under-resuscitation worsens shock. 1

Seizure Management

• Treat suspected or proven seizures early—seizures occur in 15% of bacterial meningitis patients and are associated with worse outcomes. 1, 2
• Patients with suspected status epilepticus (including non-convulsive status) with fluctuating GCS off sedation or subtle abnormal movements require EEG monitoring. 1, 2

Monitoring and Prognostic Considerations

ICP Monitoring

• Routine use of invasive ICP monitoring is not recommended in meningoencephalitis. 1
• However, observational studies suggest that continuous ICP measurement in severe cases with ICP-targeted therapy may reduce mortality. 7, 8, 9
• Mean ICP is significantly higher and cerebral perfusion pressure markedly decreased in non-survivors compared to survivors. 8

Critical Timing

• Death due to herniation is most often seen within the first week. 9
• Early neurosurgical consultation is essential because most patients who develop elevated ICP will not resolve without permanent shunt placement. 4

Common Pitfalls to Avoid

• Failing to measure opening pressure at initial LP—this is the single most critical determinant of outcome. 1, 2
• Delaying antimicrobial therapy while awaiting diagnostic procedures. 2
• Using acetazolamide or corticosteroids for ICP control. 1, 2, 4
• Performing LP in patients with focal neurologic signs or papilledema without imaging first. 1, 2
• Repeated lumbar punctures may contribute to subsequent shunt infection. 4
• Under-treating elevated ICP with inadequate CSF drainage frequency. 1, 2