Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 13 Sept 2026Clinical review pending
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Decompensating hydrocephalus
Falling consciousness, new pupillary change, bradycardia with hypertension, apnoea, bulging fontanelle or rapidly progressive vomiting may mark acute pressure failure.
Action: Call neurosurgery immediately, stabilise airway and circulation, obtain urgent brain imaging when safe, and arrange protocol-led temporary or definitive CSF diversion without compressing or tapping the valve unless specifically authorised.
Synopsis
Understand when a ventriculoperitoneal shunt provides durable cerebrospinal-fluid diversion, how its components work, and how age, aetiology and follow-up change selection.
A VP shunt diverts CSF from a ventricular catheter through a valve and subcutaneous distal catheter into the peritoneum; it controls pressure but does not cure the cause of hydrocephalus.
Decide from symptoms, neurological trajectory and serial imaging rather than ventricular size alone; chronic ventriculomegaly, atrophy and normal-pressure states can complicate interpretation.
The first pathway is a complete worked case showing indication, device choice, outcome and verification, so every step remains visible in Rapid mode.
Key red flags
A previously shunted patient with reduced consciousness or a new focal deficit has possible acute malfunction until assessed urgently.
In infants, a tense fontanelle, splayed sutures, rapidly increasing head circumference, downward gaze or feeding failure can precede adult-pattern pressure signs.
Fever, wound erythema, discharge, abdominal tenderness or meningism may indicate device infection even when the reservoir and skin look normal.
Postural headache, subdural collection or slit ventricles can reflect over-drainage; small ventricles do not prove satisfactory shunt function.
Raised pressure
Headache, vomiting, reduced alertness, sixth-nerve palsy, papilloedema or gait deterioration suggest under-drainage, but manifestations vary by age and chronicity.
Infant presentation
Rapid head growth, a tense fontanelle, irritability, poor feeding, downward gaze and developmental regression may be more informative than reported headache.
Reasoning priorities
01
Neurological and age-specific examination
Establish pressure symptoms, visual findings, head growth, gait and cognition before selecting or reviewing diversion.
A deteriorating examination accelerates temporary drainage or surgery; a stable chronic syndrome permits cause-specific testing and counselling.
Worked reasoning
Worked casePersistent hydrocephalus after haemorrhage
An adult has persistent gait and cognitive decline, enlarging ventricles and failed weaning after temporary drainage for aneurysmal subarachnoid haemorrhage.
Context: verify that symptoms and serial ventricular enlargement persist after the acute haemorrhage has been secured, while excluding sedation, infarction, metabolic disturbance and infection.
Reasoning: document the response and failure pattern during temporary drainage; persistent symptomatic hydrocephalus makes durable CSF diversion reasonable in the aSAH-specific NICE pathway.
Outcome: discuss VP shunt implantation, including valve choice, blockage, infection, haemorrhage, over-drainage, abdominal complications, revision and alternatives relevant to anatomy.
Verification: record post-operative neurological baseline, wound and abdominal findings, ventricular comparison and the exact device and setting; give failure-symptom and access advice before discharge.
National guidance is shown before implementation-dependent detail. Apply principles in context and verify current guidance when a decision affects care. Source check completed 13 Sept 2026; clinical approval remains outstanding.
NICE NG228 aneurysmal subarachnoid haemorrhageNICE NG228, published 23 November 2022; recommendations 1.3.2–1.3.5 read 13 September 2026. Supports symptom-plus-serial-imaging diagnosis and temporary or permanent CSF diversion only in people with aneurysmal subarachnoid haemorrhage; it is not a universal hydrocephalus algorithm. Chapter-specific use: ventriculoperitoneal shunts.
CNS paediatric hydrocephalus guideline on ETV and shuntsCongress of Neurological Surgeons paediatric hydrocephalus guideline, 2020 update with literature through November 2019, Part 4 read 13 September 2026. In studied childhood aetiologies, both shunting and ETV are options and no blanket preference is supported; adult selection is not inferred. Chapter-specific use: ventriculoperitoneal shunts.
CNS paediatric shunt-infection prevention guidelineCongress of Neurological Surgeons paediatric hydrocephalus guideline, 2020 update, infection-prevention recommendations read 13 September 2026. Supports perioperative antibiotics and antibiotic-impregnated tubing in children requiring shunts; it does not define adult prophylaxis or local theatre doses. Chapter-specific use: ventriculoperitoneal shunts.
IDSA healthcare-associated ventriculitis and meningitis guidelineIDSA 2017 guideline, recommendations 1–23, 34–36, 62 and 66–81 read 13 September 2026. Covers adults and children with healthcare-associated infection; normal CSF indices or a negative Gram stain do not exclude infection, culture is central, and an infected shunt generally requires complete removal, external drainage and intravenous antimicrobials. US guideline and local microbiology policy still governs empirical drugs. Chapter-specific use: ventriculoperitoneal shunts.