INTRODUCTION TO DEFINE ICP TO ENLIST FACTORS CAUSING INC ICP TO ENLIST INDICATION ANDCONTRA INDICATION OF ICP MONITORING TO BRIEF CONSIQUENCIES OF INC ICP TO EXPLAIN ASSESSMENT OF INC ICP TO BRIED WARNING SIGN OF ICPMONITORING TO EXPLAIN VARIOUS INVASIVE AND NON INVASIVE METHOD OF ICP MONITORING

2. INCREASED
INTRACRANIAL
PRESSURE
By,
Krishna V Gandhi
Rollno.10
Final Year MSC (N) - MSN
SVBCON

3. OBJECTIVES
 INTRODUCTION
 TO DEFINE ICP
 TO ENLIST FACTORS CAUSING INC ICP
 TO ENLIST INDICATION ANDCONTRA INDICATION OF ICP MONITORING
 TO BRIEF CONSIQUENCIES OF INC ICP
 TO EXPLAIN ASSESSMENT OF INC ICP
 TO BRIED WARNING SIGN OF ICPMONITORING
 TO EXPLAIN VARIOUS INVASIVE AND NON INVASIVE METHOD OF ICP
MONITORING

4. HISTORICAL REVIEW
1. Understanding of the CSF circulation — MAGENDIE who described a
small foramen in the floor of the fourth ventricle 175 years ago.
2. ALEXANDER MONRO &GEORGE KELLIE((1823- 24,Scotland) )
defined closed box concept
3. 1891 QUINKE introduced LP allowing CSF sampling & measurement
4. 1900 CUSHING describes the classic Triad seen with severely elevated
ICP
5. 1960 LUNDBERG introduced long term continuous ICP monitoring
via an indwelling intraventricular catheter.

5. INTRODUCTION
1. The skull is a rigid structure.
2. It contains:
Brain – 80-85% 1300-1750 mls
Blood 5-8%
Cerebro spinal fluid (CSF) 8-12%

6. NORMAL CSF
 Average intracranial volume : 1400 to 1700 ml
 CSF occupies about 150 ml : 10 percent approx.
 Rate of formation : 0.35ml/min = ~20ml/hour =
~500ml/day
 Renewed 3 – 4 times a day
Sites of production Choroidal plexus : 70-80 percent
Extra-choroidal : 20-30 percent

7.  Cerebral blood flow = pressure / resistance
 Cerebral blood flow =
cerebral perfusion pressure/cerebral vascular
resistance

8. MONRO KELLE HYPOTHESIS

9. COMPENSATORY MECHANISMS FOR
EXPANDING MASSES
Immediate
 Decrease in CSF volume by movement of fluid to the lumbar area.
 Decrease in the blood volume by squeezing blood out of sinuses
Delayed
 Decrease in the extra-cellular fluid.

10. DEFINITION
 INTRACRANIAL PRESSURE (ICP) is the pressure inside the
skull and thus in the brain tissue and cerebrospinal fluid (CSF)
Normal range 5 – 15 mm Hg
 INCREASED INTRACRANIAL PRESSURE (ICP)
Increased ICP is defined as a sustained elevation in pressure above
20mm of Hg

11. LEVELS ICP In mmHg
Normal 5-15
Mild 16-20
Moderate 21-30
Severe 31-40
Very severe 41 and above

12. FACTORS CAUSING INC ICP
 Cerebral Oedema
 Vasogenic
 Cytotoxic oedema
 Post-Cardiac Arrest
 Inflammatory—Meningitis/Encephalitis
 Intra Cranial Space Occupying Lesions
 Enlarged ventricular system
 Pneumocephalus
 Increase in C.B.F.
 Impaired cerebral venous drainage

13. INDICATION OF ICP MONITORING
 Glasgow Coma Scale (GCS ) < 8
 Posturing (extension, flexion)
 Bilateral or unilateral pupil dilation (except with Epidural
Hematomas)
 CT Scan results showing edema and/or mid-line shift
 Physical assessment /neurological assessment findings which
indicate a need for monitoring

14. CONTRAINDICATIONS
 Awake patient
 Coagulopathy

15. CONSEQUENCES
 Internal herniation:- Temporal lobe is
pushed down though Tentorium in cisura
 External herniation:- Cerebellar tonsills/
peduncle herniate through foramen
magnum → Compressing over IV
ventricle → ↓CPP → Death ==
“CONING”

16. ASSESSMENT OF ICP
1. THROUGH CLINICALASSESSMENT
 Altered level of consciousness
 Change in speech
 Altered pupillary reactivity
 Changes motor and sensory activities
 Headache
 Vomiting
 Pupillary oedema
 Bradycardia
 Cheyne stroke respiration
 Brain death

17. WARNING SIGN
 Confusion
 Agitation
 Restlessness
 Aggressiveness
 Personality change
 Poor GCS

18. ICP MONITORING
 The monitoring of intracranial pressure is used in treating severe
traumatic brain injury patients. This process is called intracranial
pressure monitoring. All current clinical available measurement
methods are invasive and use various transducer systems.

19. TECHNOLOGY
• Ventriculostomy
• Fiberoptic catheter
• Subarachnoid
bolt/screw
LOCATION
• Intraventricular
• Intraparenchymal
• Epidural
• Subdural
• Subarachnoid
NON INVASIVE
• Transcranial doppler
ultrasonography
• Tympanic membrane
displacement
• Optic nerve sheath
diameter
• MRI/CT
• Pupilometry

20. External Ventricular Drainage (EVD)/
Ventriculostomy
 Gold standard test
 Catheter inserted into lateral ventricles and coupled to an external
transducer through a burr hole.
 In addition to measuring ICP, this technique can also be used for
drainage of CSF and administering of medicine intra- thecally, for
example, antibiotic administration in cases of ventriculitis,
possibly resulting from EVD placement itself.
 Allows for removal / sampling of CSF.
 Ventriculostomy has to be kept at ideal height, Targus of ear.

22. ADVANTAGES DISADVANTAGES
Serves a lot as a therapeutic device Accurate placement of an EVD may be
difficult
Low cost Complication includes mal position
Most accurate Occlusion
Hemorrhage
Infection

23. NORMAL ICP WAVEFORM
PERCUSSION WAVE TIDAL WAVE
DICROTIC WAVE

24.  Prominent P1 wave :The
systolic BP is too high
 Diminished P1 wave • If the
systolic BP is too low, P1
decreases and eventually
disappears, leaving only P2. •
P2 and P3 are not changed by
this.

25.  ROUND ICP wave : ICP
critically high
 Diminished p2 and p3 wave :
hyperventilation

26.  PROMINENT P2 wave :
The mass lesion is increasing in volume
• The intracranial compliance has decreased
• An inspiratory breath hold (as ICP will also rise)
• If P2 is higher than P1 – it indicates intracranial hypertension

27. WHEN TO PULL OUT EVD?
 CT evidence of reduction of cerebral oedema
 Improved icp
 Evd is infected

28. FIBEROPTIC INTRACRANIAL
PRESSURE MONITOR
 Fiberoptic devices for ICP monitoring in which the catheter tip
measures the amount of light reflected off a pressure-sensitive
diaphragm .
 The most widely studied fiberoptic device is the Camino
fiberoptic ICP monitoring device
 The sensor is placed within the ventricles of a brain tissue and
provides a direct measurement of brain pressure

29. ADVANTAGES DISADVANTAGES
Ease of insertion- right frontal Zero drift.(Recalibration cannot be
performed 2 mm Hg (first 24 hrs); 1 mm
Hg (first 5 days) – Manufacturer 0.5 – 3.2
mm Hg drift – Actual)
Can be inserted in severely compressed
ventricles or those with midline shift
Mechanical problems (breakage or
dislocation of fibrooptic cables )
Accuracy
low complication rate

30. THE SUBARACHNOID SCREW (BOLT)
 A subdural screw or bolt is a hollow screw that is
inserted through a hole drilled in the skull. It is
placed through dura mater.
 This allows the sensor to record from inside the
subdural space.
 It is placed just through the skull between the
arachnoid membrane and cerebral cortex
 It does not allow for CSF drainage but ideal for mild
to moderate head injury
 It can easily converted to ventriculostomy if the
patient decompensate.

31. ADVANTAGES DISADVANTAGES
Does not penetrate the brain It is unable to drain CSF
Lower risk of infection than the
intraventricular catheter
The accuracy is questionable
It is easier to place

32. MINIATURE STRAIN GAUGE
TRANSDUCER
It has a microchip pressure sensor at the tip of a flexible nylon
cable that produces different electricity based on pressure.

33. Advantages
• can be placed in various compartments, including the
ventricle, parenchyma, and subdural space
Disadvantages
• Less accurate.

34. SPIEGELBERG PARENCHYMAL
TRANSDUCER
 Using an Air-Pouch mounted in the tip region of a dual lumen
probe.
 One lumen transmits the pressure to the Brain-Pressure Monitor.
 The second lumen is used for drainage of CSF.

35. SPIELBERG COMPLIANCE MONITOR
 Compliance is defined as change in volume per unit change in
pressure
 A low compliance state means that a small change in volume lead
to a large change in pressure
 Inverse relationship between compliance and ICP
 To measure compliance, the monitor injects a small amount of air
into the air balloon pouch and measures the pressure response to
this change in volume

36. NON INVASIVE ICP MONITORING
 ONSD : Optic nerve sheath diameter
 Venous ophthalmodynamometry
 Tympanic membrane displacement
 Transcranial doppler
 VEP (visual evoked potential)

37. OPTIC NERVE SHEATH DIAMETER
(ONSD)
 ONSD , which can be measured by ultrasound,
correlates with ICP.
 demonstrated a strong linear relationship between
ONSD and ICP.
 But the critical value of ONSD for detecting
elevated ICP (ICP >20 mm Hg) is different in the
various studies, thus limiting its potential use at this
time

38. TECHNIQUE:
 Select the high frequency linear array probe.
 Apply ultrasound gel liberally to the closed eyelid.
 Resting the probe hand on a bony structure such as the forehead or brow ridge
 Stabilizes the image and lowers the risk of inadvertent pressure on the globe.
 Place the ultrasound probe lightly over the gel in a transverse orientation
initially.
 Both the eye should be scanned, in case of unilateral papilledema
 First locate a point 3mm in posterior to the optic disk at this point place the
calipers at 90degree to the axis of optic nerve to measure the diameter of optic
nerve.
 ONSD Measurement Common cut-off is 5 mm

39. ADVANTAGES DISADVANTAGES
Reproducibility of measurements Lack of a uniform cut-off value
Portability of equipment Operator dependent
The non-invasive nature of the technique
Potential risk of pressure injury to the
globe
Rapid performance
Avoidance of ionising radiation
Avoidance of patient transport for imaging
Relatively low costs
Ready availability of equipment

40. VENOUS OPHTHALMODYNAMOMETRY
 It, which measures venous opening pressure (VOP), to calculate
ICP.
 Drawback -requires dilation of the pupil to perform the
measurement.
 Both ONSD and VOP measurement can be performed only
intermittently and therefore can be used just as a screening tool
for ICP elevation rather than as a continuous monitor.

41. TYMPANIC MEMBRANE DISPLACEMENT
 TMD gives an idea of Cochlear fluid pressure acts as a
surrogate for ICP.
 High cochlear fluid pressure causes an inward- directed
movement of the tympanic membrane, low cochlear fluid
pressure causes an outward movement. This movement is
measured as the mean volume displacement , But less
accurate.

42. TRANSCRANIAL DOPPLER
 Measuring ICP based also on changes in patterns of blood flow
velocity in the intracranial arteries, which can be assessed by
TCD
 The Middle Cerebral Artery is considered a biologic pressure
transducer whose vessel wall deflects in response to mural
pressure , modulating according to the pulsatile waveform of CBF
 ICP can be derived with various mathematical models by using
various blood flow velocity data & variations in TCD waveform
morphologies

43. VEP (VISUAL EVOKED POTENTIAL)
 Delay in visual evoked potentials is observed patient with raised
ICP

44. SUMMARY
 DEFINE ICP
 FACTORS CAUSING INC ICP
 INDICATION AND CONTRA INDICATION
 CONSIQUENCIES
 ASSESSMENT OF INC ICP
 VARIOUS INVASIVE AND NON INVASIVE METHOD OF ICP MONITORING

45. BIBLIOGRAPHY
1. Basvanthappa B.T”MEDICAL SURGICAL NURSING”1st edition , 2005 Jaypee
Brothers Publications, NewDelhi,Page No.1142-1144.
2. Black J.M. Hawk, J.H. (2005) Medical Surgical Nursing Clinical Management for
Positive Outcomes. (7th ed) Elsevier. Page No.986-990 .
3. Chintamani Lewis”MEDICAL SURGICAL NURSING ”South Asia edition 2nd
volume 2015,Elseiver Publication,Page No.1541.
4. Lewis, Heitkemper&Dirksen (2000) Medical Surgical Nursing Assessment and
Management of Clinical Problem (6 thed) Mosby. Page No.862
5. Phipps W.J., Long C.B. & Wood N.F. (2001) Shaffer’s Medical Surgical Nursing
B.T.Publication Pvt. Ltd. New Delhi. Page No.1418-1421.