Morning Report: 2/5/2013

Here’s Dr. Shin with today’s Morning Report!

How to Tap a VP Shunt

Ventriculoperitoneal (VP) shunts, which are used to treat hydrocephalus, shunt cerebrospinal fluid (CSF) from the lateral ventricles of the brain into the peritoneum. Tapping or aspirating the shunt is performed to obtain more information for evaluation for shunt infection and blockage and also therapeutic reasons.

Indications

  • Suspected ventriculoperitoneal (VP) shunt infection or meningitis
  • Suspected VP shunt blockage
  • Severely raised intracranial pressure in the presence of a VP shunt

Contraindications

  • Infection over the entry site

Because shunt aspiration removes cerebrospinal fluid (CSF) from the supratentorial compartment, increased intracranial pressure is not a contraindication.

  • Review the shunt series imaging or previous imaging to locate the shunt reservoir.
  • If hair overlies the reservoir, parting and gelling the hair away from the shunt is often enough. Otherwise, the area around the reservoir can be shaved with a razor. In children, this should be avoided, if possible.
  • Clean the skin with an antiseptic (eg, povidone-iodine) solution. Circle outward from the entry site or radially with each swab.
  • Apply a sterile fenestrated drape over the reservoir site as shown below
  • Insert a small (23 ga or smaller) butterfly needle perpendicular to the skin into the reservoir, as shown below. Once entered, a drop in resistance is felt. Advance slowly until the bevel of the needle is fully inside the reservoir;then, hold the needle securely as the cerebrospinal fluid
  • If flow is poor, slightly adjust the angle of the needle or alter the needle’s depth. Note that poor flow is strongly correlated with proximal shunt obstruction
  • Measure the opening pressure using a manometer. It is measured vertically from the top of the CSF column to the level of the reservoir or to the level of the tragus of the ear.

 

Vamsi Krishna Chinthapalli, MBBS, MRCP, MRCS  Et. Al. Ventriculoperitoneal Shunt Tap. February 2012. http://emedicine.medscape.com/article/81058-overview

The views expressed on this blog are the author's own and do not reflect the views of their employer. Please read our full disclaimer here. Any references to clinical cases refer to patients treated at a virtual hospital, Janus General Hospital.
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Jay Khadpe MD

Editor in Chief of "The Original Kings of County" Assistant Professor of Emergency Medicine Assistant Residency Director SUNY Downstate / Kings County Hospital

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