Q&A 76.4
Prepared by UK Medicines Information ( UKMi ) pharmacists for NHS healthcare professionals
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Prepared: January 2012
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Hydrocephalus is a neurological condition resulting from an accumulation of cerebrospinal fluid (CSF) which is managed by implanting a shunt system to remove excess CSF.
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There are two types of shunt system; ventriculo-peritoneal (VP) which discharges CSF into the peritoneum and ventriculo-atrial (VA) which discharges CSF into the right atrium.
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There have been no randomised controlled trials evaluating the use of antibiotic prophylaxis to prevent secondary infection from a distant source, including the mouth, in patients with VP or
VA shunts.
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The risk of CSF shunt infection following dental procedures appears to be almost negligible.
There are no reported cases of CSF shunt infection following a dental procedure. There is no evidence that Streptococci isolated from CSF shunt infections have been of oral origin.
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On this basis, patients who have a VP or VA shunt do not require antibiotic prophylaxis prior to dental procedures to prevent shunt infections.
Hydrocephalus is a neurological condition resulting from an accumulation of cerebrospinal fluid (CSF) within the ventricles and/or subarachnoid space, leading to raised pressure within the brain.
Accumulation occurs either due to over production of CSF or to obstruction of normal drainage [1,2,3].
Hydrocephalus occurs in approximately 1 in every 1,000 births [1,2].
Hydrocephalus is managed by implanting a shunt system to remove excess CSF. There are two types of shunt. Each system comprises three components; a proximal drainage tube usually inserted into the lateral ventricle of the brain, a valve situated on the surface of the skull and a distal catheter, which is tunnelled subcutaneously via one of two routes [4,5,6]. In ventriculo-peritoneal (VP) shunts the catheter is tunnelled subcutaneously from the valve to the abdomen where it discharges into the peritoneal cavity and never comes directly into contact with blood [4,5]. In ventriculo-atrial (VA) shunts the catheter enters the internal jugular vein and is placed in the right atrium of the heart where it discharges CSF directly into the bloodstream. VA shunts were the first shunts to be used in hydrocephalus but today the majority of shunts fitted are VP shunts [5,6]. VA shunts may be fitted if a
VP shunt has failed or is not possible [6]. Theoretically, VA shunts are more susceptible to infection than VP shunts [7]. It is reported that infection occurs in 3% to 27% of patients following shunt insertion [8].
What causes shunt infections?
Most shunt infections occur within two months of placement. They are internal and are secondary to colonisation of the shunt lumen by skin or airborne bacteria entering the CSF or shunt during the placement operation or immediately postoperatively during wound healing [8,9]. Infections involving the tissues adjacent to the shunt tubing are rare [9]. VP shunts can also be infected after local injury and occasionally from peritonitis, appendicitis and perforation of the bowel [5].
From the NHS Evidence website www.evidence.nhs.uk

Gram positive organisms (e.g. Staphylococci, Streptococci) account for over 90% of shunt infections
[8].
Have oral bacteria been associated with shunt infection?
The mouth is colonised by around 700 strains of bacteria.
The largest group of bacteria, accounting for half of all oral bacteria, are alpha-haemolytic Streptococci [10]:
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S. mutans and S. sobrinus - most important causes of caries.
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S. oralis, S. sanguis, S. mitis - account for up to 50% of Streptococci in plaque.
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S. salivarius - accounts for about half the Streptococci in saliva.
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S. intermedius, S. angiosus, S. constellatus – commonly found in dental abscesses.
Many dental procedures produce transient bacteraemia (e.g. dental extractions, scaling and periodontal surgery). However, levels of bacteraemia associated with non-invasive procedures (e.g. tooth brushing, dental flossing and chewing) can approach those following invasive dental procedures
[11,12]. If oral health is poor, the frequency and magnitude of bacteraemia is thought to be high.
Oral microflora, such as alpha-haemolytic Streptococci, have been isolated in up to 4% of shunt infections, but as part of a mixed infection [13].
An article published in 1998 [5] reported that over the previous 30 years there were no reported cases of CSF shunt infections caused by a dental procedure. In a small pilot study, 14 patients with VP shunts underwent minor dental procedures (prophylactic procedures and fluoride application) with no antibiotic prophylaxis. Over the 12 months follow up no patients showed signs of infection [5].
There have been no randomised controlled trials evaluating the use of antibiotic prophylaxis to prevent secondary infection from a distant source, including the mouth, in patients with VP or VA shunts.
When should antibiotic prophylaxis be used?
Antibiotic prophylaxis is defined as use of an antimicrobial agent before any infection has occurred for the purpose of preventing a subsequent infection [12]. Criteria for antibiotic prophylaxis against infection have been developed and include [12]:
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the health benefits must outweigh the antibiotic risks,
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the choice of antibiotic should be made on the single microorganism most likely to cause an infection,
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the cost –benefit ratio must be acceptable.
Is antibiotic prophylaxis used to prevent other distant site infections following dental procedures?
In March 2008 the National Institute for Health and Clinical Excellence (NICE) advised that antibiotic prophylaxis to prevent endocarditis is not recommended for any dental procedure [12]. This was a paradigm shift in practice. Reasons for the recommended change in practice included:
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Everyday activities, such as chewing and brushing teeth, cause bacteraemia far more frequently than dental procedures. Therefore these everyday activities almost certainly present a far greater risk of infective endocarditis than a dental procedure.
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The causal link between a recent dental procedure and the development of infective endocarditis has not been proved.
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Routinely prescribing antibiotic prophylaxis for patients at risk of infective endocarditis increases the likelihood that antibiotic resistance will emerge.
Should patients with hydrocephalus shunts be given prophylactic antibiotics for dental procedures?
No [6,14]. When assessing the need for antibiotic prophylaxis in patients with hydrocephalus shunts requiring dental procedures many of the conclusions made by NICE when assessing endocarditis prophylaxis are relevant (see above). Although the consequence of shunt infection is serious (mortality rate of 20 to 50% [4]), the risk associated with dental procedures appears to be almost negligible.
From the NHS Evidence website www.evidence.nhs.uk

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There have been no randomised controlled trials evaluating the use of antibiotic prophylaxis to prevent secondary infection from a distant source, including the mouth, in patients with VP or VA shunts.
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There are no national or international guidelines advising on antibiotic prophylaxis required to cover invasive procedures undertaken at sites distant to CSF shunts.
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The conclusions of this Q & A have been arrived at after consideration of the available evidence and consultation with local specialists.
1. Shine Charity (Spina bifida.Hydrocephalus.Information.Networking.Equality). http://www.shinecharity.org.uk/hydrocephalus . Accessed 12/01/12.
2. Toporek C and Robinson K. Hydrocephalus: A Guide for Patients, Families, and Friends 1999,
O’Reilly & Associates Inc. Chapters One and Four. Downloaded from ‘Patient Centered Guides,
Hydrocephalus Center’. http://www.patientcenters.com/hydrocephalus/ Accessed 14/12/07,
11/11/09 and 12/01/12.
3. Patient UK. PatientPlus. Hydrocephalus. http://www.patient.co.uk/doctor/Hydrocephalus.htm
Accessed 04/01/12.
4. Finch RG, Greenwood D, Ragnar Norrby S and Whitley RJ, editors. Antibiotic and chemotherapy, anti-infective agents and their use in therapy. 8th edition: Churchill Livingstone; 2003. Chapter 45
Pages 594-598.
5. Helpin ML, Rosenberg HM, Sayany Z and Sanford RA. Antibiotic prophylaxis in dental patients with ventriculo-peritoneal shunts: A pilot study. ASDC J Dent Child 1998; 65: 244-247.
6. Kandasamy J, Jenkinson MD and Mallucci CL. Contemporary management and recent advances in paediatric hydrocephalus. BMJ 2011; 343: d4191 .
7. Acs G and Cozzi C. Antibiotic prophylaxis for patients with hydrocephalus shunts: a survey of pediatric dentistry and neurosurgery program directors. Pediatr Dent 1992; 14: 246-250.
8. Kandasamy J, Dwan K, Hartley JC et al. Antibiotic-impregnated ventriculoperitoneal shunts – a multi-centre British paediatric neurosurgery group (BPNG) study using historical controls. Childs
Nerv Syst 2011; 27: 575-581.
9. BSAC working party on infection in neurosurgery. Antimicrobial prophylaxis in neurosurgery and after head injury. Lancet 1994; 344: 1547-1551.
10. Mitchell L, Mitchell D and McCaul L. Oxford Handbook of Clinical Dentistry. 5 th Edition: Oxford
University Press; 2009. Chapter 5, page 174.
11. Seymour RA, Lowry R, Whitworth JM and Martin MV. Infective endocarditis, dentistry and antibiotic prophylaxis; time for a rethink? Br Dent J 2000; 189: 610-616.
12. NICE Clinical Guideline No.64. Prophylaxis against infective endocarditis: antimicrobial prophylaxis against infective endocarditis in adults and children undergoing interventional procedures. March 2008. London: National Institute for Health and Clinical Excellence. www.nice.org.uk/nicemedia/pdf/CG64NICEguidance.pdf
Accessed 2/12/09.
13. Proctor R, Kumar N, Davies R and Porter S. Cerebrospinal fluid shunts and dentistry – a short review of relevant literature. J Disability Oral Health 2004; 5: 27-30.
14. de Morais Gallarreta FW, Bernardotti FP, de Freitas AC et al. Characteristics of individuals with hydrocephalus and their dental care needs. Spec Care Dentist. 2010; 30: 72-76.
From the NHS Evidence website www.evidence.nhs.uk

Prepared by
Christine Randall, Senior Medicines Information Pharmacist,
North West Medicines Information Centre, Pharmacy Practice Unit, 70 Pembroke Place, Liverpool,
L69 3GF.
Contact
Email: nwmedinfo@nhs.net
Date prepared
November 2005
Updated December 2007, November 2009, and January 2012.
Checked by
Joanne McEntee and Christine Proudlove, North West Medicines Information Centre, Pharmacy
Practice Unit, 70 Pembroke Place, Liverpool, L69 3GF.
Date of check
November 2005
December 2007
January 2010
February 2012
Search strategy
Medline (1951 to date)
(ANTIBIOTIC-PROPHYLAXIS#.DE. OR DENTAL-PROPHYLAXIS#.DE.) AND
((VENTRICULOPERITONEAL-SHUNT#.DE. OR Cerebrospinal-Fluid-Shunts#.DE.) OR
HYDROCEPHALUS#.W..DE.)
Embase (1974 to date)
(ANTIBIOTIC-PROPHYLAXIS#.DE. AND (BRAIN-VENTRICLE-PERITONEUM-SHUNT#.DE. OR
CEREBROSPINAL-FLUID-SHUNTING#.DE. OR VENTRICULOATRIAL-SHUNT#.DE. OR
HYDROCEPHALUS#.W..DE.)) AND DENTAL-CARE
Google UK: Hydrocephalus; “ventriculoperitoneal shunt” and “dental prophylaxis”
Textbooks:
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Scully C & Cawson RA, Medical Problems in Dentistry, 5th edition: Churchill Livingstone; 2005
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Lockhart PB, editor. Dental Care of the Medically Complex Patient, 5th edition: Wright; 2004
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Finch RG, Greenwood D, Ragnar Norrby S and Whitley RJ, editors. Antibiotic and chemotherapy
Anti-infective agents and their use in therapy 8th edition: Churchill Livingstone; 2003.
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Laura Mitchell, David A. Mitchell, and Lorna McCaul. Oxford Handbook of Clinical Dentistry, 5th edition: Oxford University Press; Jan 2009.
Clinical experts (2005):
Dr Mike Martin, Consultant in Oral Microbiology, Liverpool University Dental Hospital
Paediatric and Adult Neurologists, Liverpool.
From the NHS Evidence website www.evidence.nhs.uk