2. INTRODUCTION
Cerebrospinal fluid is a clear fluid
present in the ventricles of the brain,
the central canal of the spinal cord
and the subarachnoid space.
3. Function of CSF
Protects, lubricates the brain.
Provides nutrients
Removes waste.
Transport medium for nutrients and
metabolites, endocrine substances and
neurotransmitters.
Biomarker for disease diagnosis.
Contains growth factor and micro RNA
for neurogenesis.
Blood-CSF barrier
4.
5. FORMATION OF CSF
3 sites :
Choroid plexus (50-70%)
Ependymal surfaces of ventricles
Perivascular spaces.
6. Formed at rate of : 500-600ml/day OR
: 0.35-0.40ml/min
• Turn over time : 5-7hours = 4
times/day
• CSF volume : 150ml (125ml in cranial
and subarachnoid spaces+ 25ml in
ventricle)
7. CSF PRESSURE
(mm Hg)
CHILDREN 3.0-7.5
ADULTS 4.5-13.5
CSF VOLUME (ml)
INFANTS 40-60
YOUNG CHILDREN 60-100
OLDER CHILDREN 80-120
ADULTS 100-160
8. Choroid plexus
It is a cauliflower like growth of blood
vessels covered by a thin layer of
epithelial cells.
It projects into temporal horn of lateral
ventricle, posterior part of 3rd ventricle
and roof of 4th ventricle.
9. Nerve supply: branches of vagus and
glossopharyngeal nerve and sympathetic
nerves.
Blood supply:
Body of lateral ventricle Posterior choroidal artery
Body of third ventricle Anterior choroidal artery
Temporal horns Superior cerebellar artery
Fourth ventricle Posterior inferior cerebellar
artery.
10.
11. Formation of CSF at choroid
plexus
Filteration of plasma across choroidal
capillary endothelium into interstitial
compartment according to pressure
gradient.
Secretion of ions and water across
epithelial cells.
15. ABSORPTION OF CSF
• All CSF formed is reabsorbed into the
venous circulation through arachnoid
villi or granulations.
• These villi project the subarachnoid
spaces into the venous sinuses of the
brain and occasionally into the venous
of the spinal cord.
25. Intracranial Pressure(ICP)
The intracranial and spinal vault
contains neural tissue, blood and CSF
and is enclosed by duramater and
bone.
The pressure within this space –
intracranial pressure.
Normal ICP is <15mm Hg.
This pressure is regulated by rate of
formation of CSF and resistance to
CSF reabsorption by arachnoid villi.
26. Monro Kellie Doctrine
The sum of volumes of brain, CSF and
intracranial blood is constant.
An increase in volume of one component will
be compensated by decrease in one or both
of the remaining two.
34. Methods to measure ICP
Pressure transducers can be placed
under aseptic conditions into subdural
space (subdural bolt), brain
parenchyma or ventricle
(ventriculostomy)
Lumbar arachnoid catheter.
36. Hydrocephalus
One of the most common pediatric and
adult neurosurgical disorder,
An abnormal increase in amount of CSF
resulting from a disturbance of formation,
flow or absorption of CSF thus resulting in
enlarged cerebral ventricles.
37.
38. Clinical presentation :
In infants and newborn :
Cranium enlarges>facial growth
Irritable, lethargy
Delayed milestones
Vomiting
Decrease oral intake
Macewen’s sign- cracked pot sound
on percussion over dilated ventricle
Hyperactive reflexes
41. Treatment :
Medical therapy –
Acetazolamide :25mg/kg/day PO
divided TID increase by 25mg/kg/day
until 100mg/kg/day.
Furosemide : 1mg/kg/day PO divided
TID
Correct electrolyte abnormalities
43. Anesthesia management
History taking and physical examination
– severity of ICP and neurological status.
Premedication : avoid sedation.If
required titrated dose of oral/intranasal
midazolam may be used..
Prophylactic antibiotics should be given
to lower shunt infection rate.
Monitoring : pulse oximetry, ECG, blood
pressure, capnometry, temperature
Patient head is placed 30˚head up
position.
44. Induction : high ICP and vomiting increase
risk of aspiration. So rapid sequence
induction with thiopentone (3-5mg/kg) or
propofol (2-4mg/kg) followed by
succinylcholine or rocuronium is used.
Institute hyperventilation.(PaCO2 of 25-30
mm Hg).
Avoid spontaneous ventilation in
ventriculopleural shunt ( to prevent
pneumothorax) and ventriculoatrial shunt (
to prevent air embolism).
Maintainance: air, oxygen, isoflurane/
sevoflurane, fentanyl, paracetamol,
intermediate acting non depolarising
muscle relaxants.
45. Replace loss of intravascular volume
due to emesis or diuresis with saline.
Maintain normothermia.
Extubate when fully awake.
Post operatively patient should be
nursed flat so as to avoid subdural
hemorrhage which may occur
because of rapid collpse of ventricles
in head high position. Monitor mental
status as reobstruction can occur.
46. References
Guyton and Hall Textbook Of Medical
Physiology.
Stoelting’s Pharmacology and
Physiology in Anesthetic Practice.
Stoelting’s Anesthesia Co-Existing
Diseaase.