What is the recommended management for normal pressure hydrocephalus (NPH) in an intensive care unit (ICU) setting?

Management of Normal Pressure Hydrocephalus in the ICU

For NPH patients requiring ICU-level care with acute decompensation, urgent CSF diversion via external ventricular drainage (EVD) or lumbar drainage should be performed immediately to improve neurological outcomes, followed by definitive permanent shunt placement once stabilized. 1, 2

Acute ICU Management

Immediate CSF Diversion

• Acute symptomatic hydrocephalus requires urgent CSF diversion through EVD or lumbar drainage to prevent neurological deterioration and improve outcomes 1, 2
• EVD placement is generally preferred in the ICU setting as it allows continuous ICP monitoring and controlled CSF drainage 1
• Lumbar drainage can be used as an alternative when ventricular access is challenging or contraindicated 1, 2

EVD Management Protocol

• Implement a bundled EVD protocol addressing insertion technique, aseptic management, dressing protocols, and staff education to reduce infection rates (which range from <1% to 45% without protocols) 1
• Key protocol elements include: sterile insertion technique, appropriate skin preparation, standardized dressing changes, controlled flushing procedures, and comprehensive staff training 1
• Monitor for complications including infection, hemorrhage, catheter malfunction, and overdrainage 1

EVD Weaning Considerations

• Do not routinely perform prolonged EVD weaning (>24 hours) as it does not reduce the need for permanent shunting 2
• Assess readiness for permanent CSF diversion based on clinical improvement and stabilization rather than arbitrary weaning protocols 2

Transition to Definitive Management

Permanent Shunt Placement

• Once the patient is medically stable, proceed with permanent CSF diversion (ventriculoperitoneal, ventriculoatrial, or lumboperitoneal shunt) as this is the definitive treatment for NPH 2, 3, 4
• Ventriculoperitoneal shunting remains the standard of care, with 70-90% of patients showing clinical improvement 3, 4
• Lumboperitoneal shunts are a viable alternative avoiding intracranial surgery, with 92% showing initial gait improvement and 65% maintaining improvement at 6 months 5

Valve Programming Strategy

• Set the initial valve opening pressure (VOP) as close as possible to the patient's lumbar puncture opening pressure (LPOP) to minimize overdrainage complications while maintaining symptom improvement 6
• Use MRI-safe programmable valves to allow post-operative adjustment based on symptoms and imaging 4
• Patients with smaller delta (LPOP-VOP difference) demonstrate lower overdrainage rates and better symptom improvement 6

What NOT to Do in NPH Management

Ineffective Medical Therapies

• Do not use acetazolamide or furosemide as they are not effective for reducing shunt need or treating NPH 1, 4
• Do not use serial lumbar punctures as routine treatment to avoid shunt placement, as they neither predict nor prevent the need for permanent CSF diversion 1
• Repeated LPs may provide temporary benefit in highly selected patients but should not delay definitive surgical management in the ICU setting 7

Contraindicated Interventions

• Do not use intraventricular thrombolytics (tPA, urokinase, streptokinase) as they increase secondary hemorrhage risk without reducing shunt need 1

Critical Monitoring Parameters

Neurological Assessment

• Monitor the NPH triad: gait disturbance, urinary incontinence, and cognitive impairment 3, 4
• Track improvement in these symptoms as indicators of adequate CSF diversion 3
• Watch for signs of overdrainage: orthostatic headaches, subdural collections, altered mental status 6

Imaging Surveillance

• Obtain baseline and follow-up MRI to assess ventricular size, transependymal edema (periventricular lucencies indicating active pathology), and the DESH pattern (disproportionately enlarged subarachnoid space hydrocephalus) which predicts positive shunt response 2, 4
• Serial imaging helps guide valve adjustments and detect complications 4

Common Pitfalls to Avoid

• Delaying permanent shunt placement: The spontaneous course of untreated NPH leads to nursing care dependence in the vast majority of patients; early definitive treatment improves outcomes 3
• Setting VOP too low relative to LPOP: This increases overdrainage complications without improving symptom control 6
• Attempting medical management alone: Acetazolamide and diuretics are ineffective; surgical CSF diversion is required 1, 4
• Prolonged EVD weaning protocols: These do not reduce permanent shunt need and delay definitive treatment 2