It’s a perfect sunny day in San Diego, and Ron Burgundy is about to broadcast another episode of his highest rated (local) news show. Little does the public know that Ron suffers from hydrocephalus and has a ventriculoperitoneal (VP) shunt. While on air, he becomes altered, sleepy, and garbles his speech while saying some wildly inappropriate things on air. Maybe it’s the scotchy scotch scotch? He is rushed to SD County Hospital, where you have the privilege of seeing him.
Now, VP shunt complications are most commonly a pediatric EM problem, but since Ron Burgundy is kind of like a giant child, let’s just roll with it, ok?
What are the most common causes of VP shunt failure?
VP shunt failure has 3 main causes:
- Infection
- Early / first 6 months: CNS infection.
- Later: abdominal infections that migrate proximally via catheter
- Mechanical failure
- Fracture of the shunt
- Obstruction
- Functional failure
- Over-drainage causing small “slit-like” ventricles
- CSF not absorbed in abdomen which forms pseudocysts
What imaging is needed to assess for VP shunt problem?
- Non-contrast Head CT – the most important imaging to get. It is useful to have a prior one so you can compare the degree or change in hydrocephalus.
- VP shunt series XR- a series of plain x-rays following the shunt from skull to abdomen. This can theoretically show an obstruction but is not as helpful as a CT for diagnostic purposes. Board answer: Get the shunt series. In practice: Not always necessary or helpful.
Only take them for imaging if they are hemodynamically stable!
When do you tap the shunt in the ED?
If they are unstable with evidence of increased ICP or impending herniation, they need an emergent shunt tap before imaging. Neurosurgery should always be called and involved immediately.
Components: Proximal catheter, 1-way valve, reservoir, distal catheter.
Tap the reservoir: No or little return is indicative of a proximal occlusion. High pressure with lots of return are indicative of distal occlusion.
Check out this video for a rather dry rendition of how to tap shunts.
References:
Bober J, Rochlin J, and Marneni S. Ventriculoperitoneal Shunt Complications in Children: An Evidence Based Approach to Emergency Dept Management. EB Medicine: 2016; Volume 13(2). EBMedicine.net
Thanks to Dr Willis and our amazing pediatric department!
Kylie Birnbaum
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