This section briefly reflects the section of a patient with a suspected shunt problem.
As mentioned one of the key complications associated with shunt’s are infection.
You see a patient whose csf aspirate is as follows:
- WCC: 1068 (92% Polymorph’s)
- RBC: 167
- Gram Stain: Gram Negative Rod’s
CSF Aspirates obtained via tapping of shunt, from an external ventricular drain, lumbar puncture can provide valuable evidence. Clearly culturing the organism from the CSF is of great diagnostic value because antibiotic therapy can be tailored accordingly. However the presence of raised WCC’s can provide evidence of active infection.
Shunts can become infected:
- Contamination of the skin flora at the time of insertion e.g Staphylococcus Epidermedis/Staphylococcus Aureus
- Breakage of the skin over the shunt
- Haematogenous- remember this is important- chest, urine, sinustis
- Contamination of the distal end of the shunt such as Peritonitis
If a shunt infection is suspected there are number of options:
- Remove the shunt
- Provide interim drainage such as in an external ventricular drainage. The advantage of this is that regular CSF samples can be taken.
- IV Antibiotics or Intra-thecal Antibiotics
- Re insertion of the Shunt when the CSF Cultures are Clear
- Sub-dural haematoma- ventricular collapse, causes the cortical surface to seperate from the dura and therefore tearing of the brdiging veins and a subdural collection develops. Reducing the pressure or changing the valve
- Shunt Obstruction- debris, choroid plexus cells, or omentum (distal catheter) can cause shunt obstruction.
- Low Pressure Headaches- this is due to overdrainge of CSF and produces headaches (OPPOSITE TO THAT of pressure headache) on standing. IV Fluids, + mobilisation can help reduce this.
For More Information see the section on assessment of a patient with suspected shunt dysfunction.