Acute hydrocephalus suspected (adult)
Headache, vomiting or falling consciousness with enlarged ventricles on CT. Call neurosurgery early. Children: paediatric neurosurgery.
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NeurosurgeryEmergency
Acute Hydrocephalus - Emergency Management
Acute Hydrocephalus - Emergency Management: Acute hydrocephalus suspected (adult) → Find the cause and check bleeding risk → Posterior fossa mass: EVD a...
Pathway Overview
19 steps
Algorithm Steps
19 total
01Start 02Action Find the cause and check bleeding risk
The cause decides the first procedure. Get CT angiography if a vascular cause is possible. No lumbar puncture until CT excludes obstructive hydrocephalus and a posterior fossa mass (herniation risk).
- Subarachnoid haemorrhage (aneurysm) or intraventricular haemorrhage
- Posterior fossa mass: cerebellar haemorrhage, infarct or tumour
- Bacterial meningitis or ventriculitis suspected: blood cultures and empirical IV antibiotics now; do not wait for LP or EVD
- Tumour elsewhere or aqueductal stenosis; previous shunt: suspect shunt failure
- Bloods: FBC (platelets), INR, APTT; list anticoagulant and antiplatelet drugs
03Warning Posterior fossa mass: EVD alone can cause harm
Upward herniation risk with EVD. Neurosurgery plans surgery and drainage together.
- Cerebellar haemorrhage with deterioration, brainstem compression, hydrocephalus or volume 15 mL or more: urgent surgical evacuation, with or without EVD
- Cerebellar infarct: EVD is a reasonable first step, with cautious drainage; suboccipital decompression if no improvement
- Posterior fossa tumour: urgent neurosurgical plan; drain CSF cautiously
04Warning Previously shunted: suspect shunt failure or infection
Use the VP shunt malfunction pathway. Ventricles do not always enlarge when a shunt fails.
- Urgent neurosurgical review
- Neurosurgery decides on shunt tap, revision, externalisation or EVD
- Fever or wound signs: treat as shunt infection
05Decision Symptomatic from hydrocephalus?
Yes: reduced or falling consciousness, herniation signs, or worsening headache and vomiting. No: awake with a stable exam.
- If Yes
06Action Symptomatic: urgent CSF diversion (EVD)
Do not wait for further decline. No neurosurgery on site: urgent transfer. EVD before transfer if the centre can place one but cannot treat the cause.
- Signs: reduced or falling GCS, severe headache, vomiting, new CN VI palsy, upgaze palsy
- Neurosurgery now; consent if possible
- Lumbar drain only for communicating hydrocephalus, on neurosurgical advice; never for obstructive hydrocephalus
07Warning If GCS 8 or less or herniation signs: emergency measures now
Pupil change, posturing, Cushing triad (hypertension, bradycardia, irregular breathing). EVD must not be delayed.
- Secure the airway; avoid hypoxia and hypotension; head up 30 degrees, midline
- Hyperosmolar therapy as a bridge: hypertonic saline preferred, above all if hypotensive (mannitol causes diuresis). Dose: local ICP protocol
- Brief hyperventilation (PaCO2 30-35 mmHg, less than 2 h) only as a bridge to EVD
08Warning Before EVD: anticoagulants, low platelets, unsecured aneurysm
Impending herniation: do not delay EVD for reversal when the delay is dangerous.
- Anticoagulant, antiplatelet drug, low platelets or high INR: reverse or correct before insertion if time allows (tract haemorrhage)
- Unsecured ruptured aneurysm: avoid rapid or excess CSF drainage (rebleeding risk); secure the aneurysm early
09Action Insert EVD (emergent if critical, urgent if symptomatic)
Neurosurgeon, at the bedside or in theatre, with a standard insertion protocol.
- One dose of prophylactic antibiotic before insertion
- Aseptic bundle; antimicrobial-impregnated catheter
- Frontal approach (Kocher's point) to the lateral ventricle; closed drainage system
- Zero at the tragus; drain height as set by the neurosurgeon
- CT after insertion: catheter position and tract haemorrhage
10Action EVD care after insertion
Treat the cause at the same time: secure the aneurysm, remove the tumour, treat meningitis.
- Keep ICP below 22 mmHg and CPP 60-70 mmHg (targets from TBI and ICH data)
- Clamp before moving or repositioning; re-level to the tragus after
- Record CSF output hourly; report a sudden rise or stop in output
- Sample CSF only if infection is suspected (not daily)
- No routine prolonged antibiotics or routine catheter exchange
11Decision Signs of EVD-related infection?
New fever, new or worse confusion, meningism, or rising CSF white cell count.
- If Yes
12Action EVD infection suspected: send CSF and start IV antibiotics
Take CSF from the sampling port for cell count, glucose, protein, Gram stain and culture. Do not delay antibiotics in a septic patient.
- Empirical IV: vancomycin plus cefepime, ceftazidime or meropenem (per local susceptibility)
- Beta-lactam anaphylaxis: vancomycin plus aztreonam or ciprofloxacin
- Remove the infected drain; new EVD if CSF diversion is still needed
- Doses: CNS doses from local guideline (eTG); adjust for renal function; vancomycin by levels
- Intraventricular antibiotics only if poor response to IV therapy (specialist)
- Adjust to culture results
13Action No infection or infection controlled: EVD weaning trial
Start when the cause is treated and ICP is normal. Neurosurgery decides the timing and method.
- Clamp the EVD (or raise it in steps) with close neuro obs and ICP
- Headache, falling GCS or ICP rise: open the drain and repeat CT
- Repeat CT before removal if there is any doubt
14Decision Tolerates the clamp trial?
Yes: stable exam and ICP with the drain clamped. No: symptoms, ICP rise or larger ventricles.
- If Yes
15Outcome Tolerates clamp: remove the EVD
Observe for delayed hydrocephalus after removal; repeat CT if symptoms return.
If No16Outcome Fails clamp: permanent CSF diversion
Ventriculoperitoneal shunt, or ETV for selected obstructive hydrocephalus; treat the cause (for example tumour resection). Neurosurgical decision.
If No- Path rejoins step 13Shared downstream outcome
If No17Action Awake and stable: close monitoring
Neurosurgical review. Mild acute hydrocephalus can settle without drainage.
- Neuro obs every 1-2 h (GCS, pupils)
- Repeat CT at once for any decline
- Treat the cause
- Low threshold for EVD
18Decision Declines on neuro obs or CT?
Yes: falling GCS, new signs or larger ventricles: go to urgent CSF diversion (EVD). No: stable or better.
- If Yes
- Path rejoins step 06Shared downstream outcome
If No19Outcome Stable or better: treat the cause, no EVD now
Keep neuro obs until neurosurgery is satisfied. Plan follow-up imaging.
Guideline Source
AHA/ASA 2023 Guideline for Aneurysmal Subarachnoid Hemorrhage (Hoh et al.); with AHA/ASA 2022 ICH guideline, IDSA 2017 healthcare-associated ventriculitis guideline and NCS 2016 EVD consensus (Fried et al.)
Clinical Safety Information
Clinical Decision Support — Not a Substitute for Clinical Judgment
Individual patient factors may require deviation from these recommendations.
Known Limitations
- Adults only. Children need paediatric neurosurgical care.
- SAH care (securing the aneurysm, BP, nimodipine) is in the aSAH pathway; shunted patients: VP shunt pathway.
- EVD insertion, drain height and weaning are neurosurgical decisions; follow the local EVD protocol.
- ICP and CPP targets are extrapolated from TBI and ICH data.
- Does not cover chronic or normal-pressure hydrocephalus.
Contraindicated Populations
Children (under 16 years)
Applicable Regions
USEUAUGlobal
AU: Antibiotic doses: Therapeutic Guidelines (eTG) or local guideline. Aztreonam is on the ARTG.
EU: Consistent with ESO/EANS 2025 ICH guideline on surgery for cerebellar haemorrhage over 15 mL.
US: Based on AHA/ASA aSAH 2023 and ICH 2022, IDSA 2017 and NCS 2016 guidance.
Version 2Next review: 2027-09-30
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Frequently Asked Questions
What is the Acute Hydrocephalus - Emergency Management?
The Acute Hydrocephalus - Emergency Management is a emergency clinical algorithm for Neurosurgery. It provides a structured decision tree to guide clinical decision-making, based on AHA/ASA 2023 Guideline for Aneurysmal Subarachnoid Hemorrhage (Hoh et al.); with AHA/ASA 2022 ICH guideline, IDSA 2017 healthcare-associated ventriculitis guideline and NCS 2016 EVD consensus (Fried et al.).
What guideline is the Acute Hydrocephalus - Emergency Management based on?
This algorithm is based on AHA/ASA 2023 Guideline for Aneurysmal Subarachnoid Hemorrhage (Hoh et al.); with AHA/ASA 2022 ICH guideline, IDSA 2017 healthcare-associated ventriculitis guideline and NCS 2016 EVD consensus (Fried et al.) (DOI: 10.1161/STR.0000000000000436).
What are the limitations of the Acute Hydrocephalus - Emergency Management?
Known limitations include: Adults only. Children need paediatric neurosurgical care.; SAH care (securing the aneurysm, BP, nimodipine) is in the aSAH pathway; shunted patients: VP shunt pathway.; EVD insertion, drain height and weaning are neurosurgical decisions; follow the local EVD protocol.; ICP and CPP targets are extrapolated from TBI and ICH data.; Does not cover chronic or normal-pressure hydrocephalus.. Individual patient factors may require deviation from these recommendations.
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