ED Management of VP Shunt Malfunction
In Infants and Children
Obtain Shunt series1 and Head CT2,3
for CNS symptoms/signs4
Obtain CBC/Diff 5 & Blood Cx6
if fever or other unexplained symptoms7
Consider abdominal imaging study
if unexplained abdominal symptoms/signs8
Do not pump the shunt9
Do not tap shunt even if suspect shunt infection10
Neurosurgery consult
IV Abx11 for shunt infection12
Notes:
1 Shunt series=plain radiographs of shunt valve & tubing (necessary to assess
continuity of system and rule out kinking of the tube)
2 Evaluate ventricular size & compare to previous study if available. Frequently
children have abnormal baseline ventricular size even with a normally
functioning shunt. Even with a CT unchanged from baseline, early obstruction
may be present. Obstruction occurs most often in the proximal portion of the
tubing during the first 2 years following shunt placement and is due to occlusion
by choroid plexus, glial or ependymal tissue, or clotted blood. Distal obstruction
(due to pseudocyst formation at tip, kinking, thrombosis, or occlusion of the tip
with omentum) is most common for shunts in place for > 2 years.
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Guideline for ED Management of VP Shunt Malfunction in Infants & Children
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Valves are an infrequent cause of shunt malfunction.
Consider head ultrasound if anterior fontanel is open.
CNS symptoms/signs=headache, vomiting, altered mental status, meningismus,
seizure activity, papilledema, paralysis of upward gaze, diplopia, full/expanding
fontanel, increasing head circumference (see head circumference charts for boys
and girls 2-18 years adapted from Nelhaus)
Note: WBC count is normal in 25% of patients with documented shunt
infection. CSF eosinophilia has been associated with shunt infection.
Shunt infections are most frequently caused by Staphylococcus epidermidis
followed by Staphylococcus aureus, gram-negative rods (especially in neonates),
and Propionibacterium acnes.
Unexplained symptoms include fever without source, poor feeding, behavior
change.
Patients with VP shunts can present with shunt-related abdominal processes
even in the absence of neurologic complaints. Typical causes of abdominal pain
include peritonitis due to infection of the distal tubing, intestinal perforation, or
volvulus.
Pumping the shunt gives little useful information and may actually suck debris
or choroid plexus into the shunt.
Shunt taps should be performed by neurosurgery due to risk of infecting the
hardware and difficulty in interpreting CSF cell count and opening pressure. A
shunt tap is performed by inserting a small gauge needle into the shunt reservoir
and may show poor proximal flow from the ventricular catheter, an elevated
opening pressure, or consistent improvement in symptoms after removal of CSF.
Suggested IV Abx: vancomycin (60 mg/kg/day div Q6H) + cefotaxime (300
mg/kg/day div Q6H)
Half of shunt infections occur in the first two weeks and 75% in the first 2
months after shunt placement. CSF should be analyzed for cell count, gram
stain/cx, protein & glucose. Organisms on gram stain confirm infection. There
is variability in the literature regarding the acceptable number of WBCs in the
cell count. In one study, the median number of CSF WBCs was 18 cells/mm3 in
non-infected patients and 79 cells/mm3 in infected patients. In another study,
47% of infected patients with a positive CSF culture had < 20 cells/mm.3 Even
with normal CSF analysis, 17% of patients may have a positive culture.
References:
Nelhaus G. Head circumference from birth to eighteen years. Practical composite
international and interracial graphs. Pediatrics 1968;41:106-114
Grosfeld J, Cooney D, Smith J, et. al. Intra-abdominal complications following
ventriculoperitoneal shunt procedures. Pediatrics 1974;54:791-796
Myers MG, Schoenbaum SC. Shunt fluid aspiration. Am J Dis Child 1975;129:220222
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Guideline for ED Management of VP Shunt Malfunction in Infants & Children
Schoenbaum SC, Gardner P, Shillito J. Infections of cerebrospinal fluid shunts:
Epidemiology, clinical manifestations and therapy. J Infect Dis 1975;131:543-552
Hubschmann OR, Countee RW. Acute abdomen in children with infected
ventriculoperitoneal shunts. Arch Surg 1980;115:305-307
Walters BC, Hoffman HJ, Hendrick EB et. al. Cerebrospinal fluid shunt infection.
Influences on initial management and subsequent outcomes. J Neurosurg
1984;60:1014-1021
Odio C, McCracken G, Nelson JD. CSF shunt infections in pediatrics—seven year
experience. Am J Dis Child 1984;138:1103-1108
Yogev R. Cerebrospinal fluid shunt infections: A personal view. Pediatr Infect Dis
J 1985;85:113-118
Madsen MA. Emergency department management of ventriculoperitoneal
cerebrospinal fluid shunts. Ann Emerg Med 1986;15:1330-1343
Guertin SR. Cerebrospinal fluid shunts evaluation, complications and crisis
management. Pediatr Clin North Am 1987;34:203-217
Coker SB. Cyclic vomiting and the slit ventricle syndrome. Pediatr Neurol
1987;3:297-299
Sainte-Rose C, Hoffman HJ, Hirsch JF. Shunt failure. Concepts Pediatr Neurosurg
1989;9:7
Vinchon M, Vallee L, Prin L et. al. Cerebro-spinal fluid eosinophilia in shunt
infections. Neuropediatrics 1992;23:235-240
Piatt J. Physical examination of patients with cerebrospinal fluid shunts: Is there
useful information in pumping the shunt? Pediatrics 1992;89:470-473
Kontny U, Hofling B, Gutjahr P et. al. CSF shunt infections in children. Infection
1993;21:89-92
Sood S, Kim S, Canady AI et. al. Useful components of the shunt tap test for
evaluation of shunt malfunction. Child Nerv Syst 1993;9:157-162
Cantrell P, Fraser F, Carty P. The value of baseline ct head scans in the assessment
of shunt complications in hydrocephalus. Pediatr Radiol 1993;23:485-486
Blount JP, Campbell JA, Haines SJ. Complications in ventricular cerebrospinal
fluid shunting. Neurosurg Clin North Am 1993;4:633-656
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Guideline for ED Management of VP Shunt Malfunction in Infants & Children
Watkins L, Hayward R, Andar U et. al. The diagnosis of blocked cerebrospinal
fluid shunts: A prospective study of referral to a paediatric neurosurgical unit.
Child Nerv Syst 1994;10:87-90
Kast J, Duong D, Nowzari F et. al. Time-related patterns of ventricular shunt
failure. Child Nerv Syst 1994;10:524-528
Ronan A, Hogg GC Klug GL. Cerebrospinal fluid shunt infections in children.
Pediatr Infect Dis J 1995;14:782-786
Drake JM, Sainte-Rose C. Shunt complications. In Drake JM, Sainte-Rose C (eds):
The Shunt Book. Cambridge, MA, Blackwell Scientific, 1995, pp 121-192
Piatt JHJ: Pumping the shunt revisited: A longitudinal study. Pediatr Neurosurg
1996;25:73-77
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Guideline for ED Management of VP Shunt Malfunction in Infants & Children