1. Increased Intracranial Pressure (ICP)
Dr. Maha Subih

2. Increased Intracranial Pressure (ICP)
Monro-Kellie hypothesis: because of limited space in the skull, an increase in any one skull component—brain tissue, blood, or CSF—will cause a change in the volume of the others
Compensation to maintain a normal ICP of 10 to 15 mm Hg is normally accomplished by shifting or displacing CSF
Increased ICP decreases cerebral perfusion, causes ischemia, cell death, and (further) edema

3. ICP is usually measured in the lateral ventricles, with a normal pressure of 0 to 15 mm Hg.
brain tissue (1400 g)
Blood 75 mL
CSF 75 mL
the three components are in a state of equilibrium

4. Cerebral edema
As brain tissue swells within the rigid skull, several mechanisms attempt to compensate for the increasing ICP.
These compensatory mechanisms include autoregulation as well as decreased production and flow of CSF.
Autoregulation: refers to the brain’s ability to change the diameter of blood vessels to maintain cerebral blood flow.

5. Increased Intracranial Pressure
PCO2 plays a role; decreased PCO2 results in vasoconstriction, and increased PCO2 results in vasodilatation
Brain tissues may shift through the dura and result in herniation

6. Decreased Cerebral Blood Flow
Increased ICP may reduce cerebral blood flow, resulting in ischemia and cell death. In the early stages of cerebral ischemia, vasomotor centers are stimulated and the systemic pressure rises to maintain cerebral blood flow.
Usually, this is accompanied by a slow bounding pulse and respiratory irregularities. These changes in blood pressure, pulse, and respiration are important clinically because they suggest increased ICP.

7. CPP (cerebral perfusion pressure) is closely linked to ICP
ICP and CPP
CPP (cerebral perfusion pressure) is closely linked to ICP
CPP = MAP (mean arterial pressure) – ICP
Normal CPP is 70 to 100
A CPP of less than 50 results in permanent neuralgic damage

8. Increased ICP is a life-threatening situation that results from an increase in any or all of the three components (brain tissue, blood, CSF) within the skull.
Cerebral edema is an important factor contributing to increased ICP.
Elevated ICP increases risks of brain ischemia and infarction, and is associated with a poor prognosis.

9. a mass lesion (e.g. hematoma, contusion, abscess, tumor)
Increased ICP: Causes
a mass lesion (e.g. hematoma, contusion, abscess, tumor)
cerebral edema (associate with brain tumors, hydrocephalus, head injury, or brain inflammation)
metabolic insult (e.g., hypercapnia)

10. Manifestations of Increased ICP—Early
Changes in level of consciousness
Restlessness, confusion, ↑drowsiness, ↑respiratory effort.
Headache: constant, increasing in intensity, or aggravated by movement or straining
Respiratory changes
Pupillary changes and impaired ocular movements

11. Manifestations of Increased ICP—Early

12. Late sign
Cushing’s response is seen when cerebral blood flow decreases significantly. When ischemic, the vasomotor center triggers an increase in BP in an effort to overcome the increased ICP.
A sympathetically mediated response causes an increase in the SBP with a widening of the pulse pressure and slowing of the heart rate.
The bradycardia, hypertension, and bradypnea associated with this deterioration are known as Cushing’s triad

13. Manifestations of Increased ICP— Late
As ICP increases, the patient becomes stuporous, reacting only to loud or painful stimuli.
As neurologic function deteriorates further, the patient becomes comatose and exhibits abnormal motor responses in the form of decortication, or decerebration or flaccidity or Hemiplegia.
Projectile vomiting
Loss of brain stem reflexes, including pupillary, corneal, gag, and swallowing reflexes.

14. Herniation
Herniation of the brain stem and occlusion of the cerebral blood flow occur if therapeutic intervention is not initiated. Herniation refers to the shifting of brain tissue.
The herniated tissue exerts pressure on the brain area into which it has shifted, which interferes with the blood supply in that area. Cessation of cerebral blood flow results in cerebral ischemia, infarction, and brain death.

15. Complications
brain stem herniation,
diabetes insipidus
syndrome of inappropriate antidiuretic hormone (SIADH).

16. Diagnostic tests
Lumbar puncture is avoided in patients with increased ICP, because the sudden release of pressure in the lumbar area can cause the brain to herniate.
Brain CT scan- MRI- cerebral angiogram

17. Nursing Process—Assessment
Conduct frequent neurologic assessment
Assess the LOC
Glasgow Coma Scale
the pupils : size, shape, movement, and reactivity.
Take frequent vital signs
Assess cranial nerves
ICP monitoring: in patients admitted with a
Glasgow Coma Scale score of 8 or less
an abnormal CT scan or MRI.

18. The purposes of ICP monitoring are:
to identify increased pressure early in its course (before cerebral damage occurs),
to quantify the degree of elevation,
to initiate appropriate treatment,
to provide access to CSF for sampling and drainage,
and to evaluate the effectiveness of treatment.

19. Sites of ICP monitoring:
ICP can be monitored with the use of an intraventricular catheter (ventriculostomy), a subarachnoid bolt, an epidural or subdural catheter, or a fiberoptic transducertipped catheter placed in the subdural space or in the ventricle.

20. ICP Monitoring

21. Intracranial Pressure Waves

22. Location of ICP Monitoring System

23. Management Decreasing Cerebral Edema
Osmotic diuretics such as mannitol
Corticosteroids as dexamethasone
Fluid restriction -- dehydration and hemoconcentration
lowering the body temperature—hypothermia by reducing the oxygen and metabolic requirements of the brain, thus protecting the brain from continued ischemia.

24. Management Maintaining Cerebral Perfusion
Improve cardiac output using fluid volume and inotropic agents such as dobutamine and norepinephrine (Levophed).
maintain CPP greater than 70 mm Hg
Reducing CSF & IC Blood Volume
CSF drainage: Caution should be used in draining CSF, however, because excessive drainage may result in collapse of the ventricles and herniation
Maintaining the PaCO2

25. Management Controlling Fever
Preventing temperature elevation because fever increases cerebral metabolism and cerebral edema forms.
antipyretic medications
use of a hypothermia blanket.
Prevent shivering---increase O2 consumption, and increase vasoconstriction

26. Management Maintaining Oxygenation and Reducing Metabolic Demands
Monitor ABGs &pulse oximetry
Administer high doses of barbiturates
Paralyzing medication such as pentobarbital –thiopental..
provide analgesia for pain.
cardiac monitoring, ETT + MV, ICP monitoring, serum barbiturate levels

27. Drug therapy
Fluids intravenously via an infusion pump to control the amount administered.
Intravenous 0.9% sodium chloride is preferred solution.
5% dextrose in water or 0.45% sodium chloride intravenous solutions are avoided. Why ??!
Infusion of hypertonic saline (2.7% to 3%) is used to acutely lower ICP and support intravascular volume. However, long-term patient outcome data are still being examined.
Anticonvulsants may be given prophylactically to prevent seizures. Why??!
because seizures increase metabolic requirements and cerebral blood flow and volume, thus increasing intracranial pressure.

28. Nursing Interventions
Maintaining a Patent Airway
Suctioning with care because it ICP
Coughing is discouraged because it ICP
Auscultate lung fields every 8 hours
Elevate the head of the bed

29. Achieving an Adequate Breathing Pattern
Nursing Interventions
Achieving an Adequate Breathing Pattern
monitor for respiratory irregularities
Cheyne-Stokes respirations
Hyperventilation
Irregular
Monitor the PaCO2, which is usually maintained at less than 30 mm Hg
will result in promote cerebral vasoconstriction and decrease cerebral blood flow, and therefore decreased ICP.
A neurologic observation record

30. Nursing Interventions
Optimizing Cerebral Tissue Perfusion
Proper positioning – the head is kept in a neutral (midline) position + cervical collar
Elevation of the head at 30 to 45 degrees
Avoid extreme rotation and flexion of the neck

31. Optimizing Cerebral Tissue Perfusion
Avoid extreme hip flexion intra-abdominal and intrathoracic pressures,  ICP.
minimize the stimuli that increase ICP.
Prevent constipation --Stool softeners + diet high in fiber may be indicated.
avoid enemas and cathartics

32. Nursing Interventions
Optimizing Cerebral Tissue Perfusion
Hyperventilate using 100% oxygen on MV.
Suctioning should not last longer than 15 seconds.
avoid high levels of positive end-expiratory pressure (PEEP) are avoided,  venous return to the heart and  venous drainage from the brain
Spacing of nursing interventions – watch ICP should be less than 25 mm Hg, and return to baseline within 5 minutes.
Use of sedation and a paralytic agent before initiation of nursing activities
Avoid emotional stress
calm atmosphere is maintained.

33. Nursing Interventions
Maintaining Negative Fluid Balance
osmotic, loop diuretics and Corticosteroids to reduce cerebral edema
fluids may be restricted.
assess fluid status: Vital signs, Skin turgor, mucous membranes, urine output, and serum and urine osmolality
If IV fluids are prescribed--slow to moderate rate with an IV infusion pump
indwelling urinary catheter to assess renal function hourly.
An output greater than 200 mL/h for 2 consecutive hours may indicate the onset of diabetes insipidus

34. I&O Charting

35. Nursing Interventions
Preventing Infection
Intraventricular catheter
Aseptic technique
changing the ventricular drainage bag.
checked for loose connections,
report increasing cloudiness or blood.
signs and symptoms of meningitis: fever, chills, neck rigidity, and persistent headache.

36. ICP monitoring
When ICP is monitored with a fluid system, the transducer is calibrated at 2.5 cm above the ear with the patient in the supine position; this point corresponds to the level of the foramen of Monro.

37. Interventions Maintain body temperature. Prevent shivering.
Protect the patient from self-injury. (Confusion, agitation, and the possibility of seizures increase the risk for injury).
Monitor electrolyte levels and acid-base balance.
Monitor Urinary output.

38. INTRACRANIAL SURGERY
A craniotomy involves opening the skull surgically to gain access to intracranial structures. This procedure is performed to remove a tumor, relieve elevated ICP, evacuate a blood clot, or control hemorrhage. The surgeon cuts the skull to create a bony flap, which can be repositioned after surgery and held in place by wire sutures.

39. INTRACRANIAL SURGERY
Alternatively, intracranial structures may be approached through burr holes, which are circular openings made in the skull by either a hand drill or an automatic craniotomy.
craniectomy (excision of a portion of the skull) and cranioplasty (repair of a cranial defect using a plastic or metal plate).