INCREASED INTRACRANIAL PRESSURE

 

OVERVIEW

The rigid intracranial vault contain brain tissue 1.400 gram, blood 75 ml & CSF 75 ml. The volume and pressure of these three component are usually in a state of equilibrium & maintain ICP.  Intracranial pressure are measured in the lateral ventricle, the normal pressure is 5-15 mmHg, 20mmHg above most be treated.  ICP can be measured by use of  pressure transducer.

MONRO KELLIE HYPOTHESIS- (MENRO KELLIE DOCTORINE)

·         This Hypothesis says about dynamic equilibrium of cranial content.

·         It says that inside the skull there is a limited space for expansion of cranial content.

·         When there is increase in any one of the three content ( brain tissue, blood & CSF) it change in volume of other.

Because there is limited space it expand it cause;-

²  Shift the CSF

²  Increase absorption or decrease the production of CSF.

²  Decrease cerebral blood volume.

·         ICP also increase due to minor change in blood volume & CSF volume.

·         The volume of blood & CSF increase due to –

²  Alteration of thoracic pressure( coughing, sneezing & straining)

²  Posture

²  BP & systemic o2 & CO2 level

CAUSES:-

1.      Mass lesion:-

²  Brain abases

²  Brain tumor

²  Hematoma

²  Hemorrhage

2.      Head injury:-

²  Contusion

²  Hemorrhage

²  Post traumatic brain swelling.

3.      Brain surgery

4.      Cerebral infection:

²  Meningitis

²  Encephalitis

5.      Vascular insult:-

²  Anoxic & ischemic episode

²  Cerebral infraction ( Thromboic or embolic)

6.      Toxic or metabolic encephalitis condition

²  Lead or arsenic intoxication

²  Hepatic encephalopathy

²  Uremia & Cerebral edema.

CLINICAL MANIFESTATION:-

1.      Change in level of consciousness:-

·         It occur due to insufficient oxygen supply to cerebral cortex & reticular activating system.

·         RAS is present in brain stem which have neural connection to many part of nervous system

·         Intact RAS is present in brain maintain a state of awake fullness  but interruption of impulse from RAS cause unconsciousness. Which signs are:-

²  Change in orientation

²  Decrease level of attention

²  Patient does not respond to painful stimuli

²  EEG shows decrease or absence of neural activity.

2.      Change in vital sign due to increase pressure in thalamus, hypothalamus, pons & medulla.

3.      Ocular sign:- It occur due to compression of cranial nerve III ( ocular nerve) which control pupillary size & shape. The sign are:-

²  Fixed  dilated pupil

²  Sluggish or no response to light.

²  Inability to move eye up ward

²  Ptosis

²  Blurred vision

²  Papilledema

4.      Decrease motor function:-

²  Hemiparesis or Hemiplegia

²  Decrease posture

²  Decorticate posture:- Internal rotation are adduction of the arms with flexion of  the elbow, it indicate serious damage of the brain.

5.      Headache:- Due to compression of arteries & veins cause headache.

6.      Vomiting:- Due to pressure changes in the cranium.

DIAGNOSIS:-

²  CT scan & MRI.

²  Cerebral angiography

²  EEG

²  ICP measurement

²  Brain tissue oxygenation measurement via LICOX catheter

²  Transcranial droplet studies

²  Positron emission tomography

MANAGEMENT:-

1.      Ventriculostomy:- Here a catheter is inserted to directly measure the pressure.

It can also measure by fibro optic catheter, use a sensor transducer located within the catheter tip & sensor tip is placed within the ventricle.

2.      CSF drainage:- Removal of CSF by gravity drainage to reduce the ICP

3.      Drug therapy:- Manitol 25% is an osmotic diuretics to reduce ICP by 2 ways plasma expansion & osmotic effect.

4.      Corticosteroid:- Ex- Dexamethasone:- To control vasogenic edema surrounding tumor & absence.

5.      Antacid, H2 blocker should be given to promote GI ulcer due to corticosteroid complication.

6.      Hyper ventilation therapy:- Hyperventilation is very much necessary for increase ICP. Because lowering the PaCO2 leads to constriction of cerebral blood vessel, reduced cerebral blood flow there by decrease ICP.

7.      Nutritional therapy:- Patient with increase ICP having hyper metabolic & hyper catabolic state which increase need for glucose to provide a necessary fuel for metabolism of the injured brain.

NURSINF MANAGEMENT:-

Assess GCS & pupillary response

Nursing diagnosis:-

1.      Ineffective tissue perfusion related to reduced venous or arterial blood flow as evidenced by GCS< 8

Intervention:-

·         Proper positioning, Head should be kept in a neutral position & use of cervical collar to promote venous drainage 30 -40 unless contraindicated.

·         Avoid extreme rotation of neck & fixation of neck & flexion  of neck bcoz compression of jugular vein.

·         Increase ICP

·         Avoid valsalva’s manuever

·         Mechanical ventilation

2.      Ineffective airway clearance related to demised productive reflex

Interventions:-

·         Suctioning

·         Avoid coughing

·         Elevate HOB to clear secretion

·         Maintain negative fluid balance

·         Prevent infection

·         Maintain & manage potential complication.

·         Monitor ICP.