2. OUTLINES
⢠Production and flow of CSF
⢠Physiology of ICP and Pathophysiology of increased ICP
⢠ICP waveform and interpretation
⢠ICP monitoring and technology
⢠Treatment of elevated ICP
4. PRODUCTION AND FLOW OF CSF
⢠CSF: predominately produced by choroid plexuses
⢠Absorption at cranial and spinal arachnoid villi (granulations)
⢠Volume: 125 â 150 ml: 25 ml in ventricles, 125 ml in subarachnoid
spaces
⢠Active and delicately controlled secretion + normal absorption =
ICP stable
5.
6. Sakka L, Coll G, Cazal J. Anatomy and physiology of cerebrospinal
fluid. European annals of otorhinolaryngology, head and neck
diseases. 2011;128:309-316.
7. ⢠Variation
⢠Adult humans normally form CSF 0.35 ml/min ď 400 - 600 ml/day
⢠CSF dynamics affect brain metabolism
⢠CSF formation fluctuates in disease
⢠Hypersecretion: choroid plexus papillomas
⢠Hyposecretion: NPH, AD
PRODUCTION AND FLOW OF CSF
8. PHYSIOLOGY OF CSF: PRESSURE
⢠CSF Pressure: 10 â 15 mmHg in adult that varies with
⢠Systolic pulse wave
⢠Respiratoy cycle
⢠Abdominal pressure
⢠Jugular venous pressure
⢠State of arousal
⢠Physical activity
⢠posture
9. COMPOSITION OF CSF
⢠99% water
⢠Na, Cl, Mg: higher concentration than those in plasma
⢠K, Ca: lower concentration than those in plasma
⢠CSF cell count: < 5cells/mL, no PMN, no RBC
⢠Loop diuretics and carbonic anhydrase: reduce CSF secretion and
turnover (3-5 times daily)
18. RESULTS OF RASING ICP
⢠CSF can be displaced from ventricles and subarachnoid spaces and
exit intracranial compartment via foramen magnum
⢠Intravenous blood: displaced via IJVs
⢠Arterial vasoconstriction: diffuse cerebral ischemia
⢠Cerebral herniation
19.
20. RESULTS OF RASING ICP: CT BRAIN
⢠Midline shift
⢠Obliteration of CSF cisterns
21. PATHOPHYSIOLOGY: CSF
⢠Acute obstruction of CSF flow: acute hydrocephalus
⢠Hypersecretion of CSF: structurally or functionally alteration of
choroid plexus secretion
⢠Choroid plexus papillomas and hyperplasia
⢠Malabsorption of CSF: cribiform plate obstruction
⢠Obstruction of venous outflow
22. PATHOPHYSIOLOGY: BLOOD
⢠Arterial system
⢠Vasodilatation: hypercapnia, drug reaction
⢠Venous system
⢠Obstruction of venous outflow: thrombosis, inappropriate position
of head and neck, pneumothorax
27. ICP WAVEFORM
⢠Gold standard: interventricular monitoring through
ventriculostomy
⢠Other technologies: devices inserted into
⢠Epidural space
⢠Subdural space
⢠Subarachnoid space
⢠Brain parenchyma
32. ICP INTERPRETATION: DECREASING CEREBRAL
PREFUSION
⢠Decrease amplitude of P1
⢠Due to P1=reflective of
arterial pulse in choroid
plexus
⢠Vasospasm if no raised ICP
33. ICP INTERPRETATION: DECREASING CEREBRAL
COMPLIANCE
⢠Prominent P2
⢠Increase in cerebral
bulk: edema
⢠Vasospasm if no
raised ICP
35. ICP INTERPRETATION: LUNDBERG WAVES
⢠Pathological waveforms defined by Dr. Nils Lundberg
⢠Not frequently seen but if so, in patients with resistant to
therapeutic interventions, is the sign of worse outcome
⢠Designated as
⢠A: plateau wave
⢠B: pressure pulse
⢠C: Traube-Hering arterial waves
36. LUNDBERG âAâ WAVES
⢠Plateau waves
⢠ICP elevation to 50 mmHg
for 2 â 20 minutes then
abrupt fall to baseline
⢠Intact cerebral blood flow
autoregulation
⢠But impending
uncontrollable ICP
38. LUNDBERRG âBâ WAVES
⢠ICP elevation 10 â 20 mmHg
lasting 30 sec â 2 minutes
⢠Depends on periodic breathing
(PaCO2), increased ICP,
decrease cerebral compliance
⢠Unclear value in clinical
practice
39. LUNDBERG âCâ WAVES
⢠Similar to B waves but
more rapid sinusoidal
fluctuation
⢠Seen in normal ICP
waveform
⢠Suggestive but not
pathognomonic of
increased ICP
43. EXTERNAL VENTRICULAR DRAIN
⢠A catheter placed into one of the ventricles through burr hole
⢠Gold standard
⢠Cost effective
⢠Most invasive
⢠Can also be used for CSF drainage and administration of medicine
intrathecally
44. Winn, H. Richard. Youmans and Winnâs Neurological Surgery. Phildelphia: Elsevier, 2017.
47. KOCHERâS POINT
⢠3 cm from midline
⢠1 cm anterior to coronal
suture
⢠Point needle to nasion
and tragus
⢠Most common point
https://link.springer.com/referenceworkentry/10.1007%2F978-
3-642-00418-6_544
48. PAINEâS POINT
⢠2.5 cm superior to supraorbital
margin
⢠Anterior edge of temporalis muscle
⢠Used in aneurysmal surgery via an
interhemispheric approach
53. DANDYâS POINT
⢠Occipital bur hole
⢠3 cm above 2 cm lateral to inion
⢠Infants: correspond with lambdoid
suture in the midpupillary line
⢠Higher risk for visual impairment
54. INSERTION TECHNIQUE
⢠Right (non-dominant) side is preferred unless contraindication
⢠Kocherâs point: Incision is made in sagittal plane
⢠Elevate periosteum
⢠Apply self-retaining retractor
⢠Make a bur hole 1 â 2 cm anterior to coronal suture
⢠Control bleeding by bone wax and gelfoam
⢠Durotomy by blade No.11 and cauterize dural edge by bipolar
55. INSERTION TECHNIQUE
⢠Insert ventriculostomy needle perpendicular to brain surface (point to
nasion and tragus), not more than 7 cm depth
⢠Feel popping sensation and remove stylet
⢠Make a tunnel for the catheter
⢠Insert catheter
⢠Measure opened pressure, collect CSF, and measure closed pressure
⢠Fix catheter, hemostasis, and close the skin
56. COMPLICATIONS
⢠Intracranial and tract hemorrhage
⢠Infection: Ventriculitis
⢠Technical failure
⢠Over-drainage: transtentorial herniation
⢠Kinks and blockage by air, blood, and debris
⢠Inadvertent vascular injury.
⢠Pneumocephalus and pneumoventriculi.
⢠CSF leak.
⢠Accidental fracture
⢠Accidental pull
⢠Obstruction by choroid plexus, blood clot or proteinous plug
59. PRINCIPLES
⢠ICP > 22 mmHg mandates aggressive clinical management (brain
trauma foundation 2016)
⢠Look for potential problems that exacerbate raised ICP
⢠Treat etiology:
⢠Space-occupying hematoma: craniotomy and evacuation
⢠Hydrocephalus: ventriculostomy and shunt
⢠Tumor: dexamethasone/excision
⢠Abscess: aspiration/excision
60. Czosnyka M, Pickard JD, Steiner LA. Principles of intracranial pressure
monitoring and treatment in Handbook of Clinical Neurology. Elsevier,
2017
61. FIRST LEVEL: PREVENTION
⢠Head elevation: up to 30o
⢠Maintain SBP:
⢠Age 50 â 69 keep SBP ⼠100 mmHg, other keep SBP ⼠110 mmHg
⢠Normocarbia (PaCO2 35 â 40 mmHg): no role of prophylactiv
hyperventilation
⢠Normothermia (36 â 37.5oC)
⢠Light sedation
⢠CT brain and check for surgical treatment options if ICP > 20 mmHg
⢠Avoid hyperglycemia
62. SECOND LEVEL: MORE INVASIVE
⢠CSF drainage in hydrocephalus
⢠Hyperosmolar treatment if evidence of herniation shown
⢠20% mannitol 0.25 â 1 g/kg
⢠Hypertonic saline: keep Na < 155 meq/L
⢠Steroid in vasogenic edema
⢠Mild hyperventilation (PaCO2 30 â 34 mmHg): too long will cause
global ischemia
63. THIRD LEVEL: CONTROVERSY
⢠Decompressive craniectomy
⢠Consider deeper hypothermia: 33 â 34oC
⢠Consider barbiturate coma to maintain CPP
66. REFERENCES
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68. REFERENCES
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