- Is an increase in the water content of the brain tissue. When cerebral edema occurs as a result of trauma, hemorrhage, tumor, abscess or ischemia, an increase in ICP occurs.
- When the pressure exerted by a mass in the brain is not equally divided, result in shifting or herniation of the brain from one compartment of high pressure to one of lower pressure.Clinical Manifestations
- Change in level of consciousness is the most sensitive and important indicator of neuro status
– Early signs may be nonspecific: restlessness, irritability, generalized lethargy
– Determine the level of stimulus needed to arouse the patient (verbal, touch, shaking?)
– Content of consciousness: orientation
– Speech: clear, coherent, slurred, distorted, aphasic, incomprehensible sounds, no effort to speak
– Report changes immediately.
– Changes in vital signs-
– Increasing systolic blood pressure
– Widening pulse pressure
– Pulse slowing and is bounding
– Irregular respiratory pattern
– May also have a change in temperature
– Ocular signs
– Pupil changes are from pressure on third cranial oculomotor nerve result in dilation of pupil
– Pupils become sluggish, unequal. This is because of brain shift. May also be pressure on other cranial nerves
– A fixed, unilaterally dilated pupil indicates herniation of the brain
– Motor ability is controlled by nerve tracks originating in the frontal lobes of the brain.
– Distortion of brain tissue along these pathways can cause motor dysfunction.
– Patient may exhibit localization to painful stimulus or withdraw from it.
– Motor strength and tone are assessed in all 4 extremities.
– Decorticate posturing now called abnormal flexion,
– Decerebrate posturing now called abnormal extension.
– Decrease in motor function
– May have hemiparesis or hemiplegia
– May see posturing – either decorticate or decerebrate
– Decerebrate – more serious from damage in midbrain and brainstem
– Decorticate – from interruption of voluntary motor tracts
– From compression on the walls of cranial nerves, arteries and veins
– Straining and movement makes worse
– NOT preceded by nausea- “unexpected”
– May be projectile
– Cerebral angiography
– No lumbar puncture if there is ICP because sudden release of pressure can cause brain to herniate
– ABG’s – keep O2 at 100% and PCO2 as related to ICP (25-35)
- Mannitol – Rapid short acting diuretic that decreases ICP. Decreases total brain water content
– Watch fluids and electrolytes closely (I and O and labs)
– Don’t give in cases of renal failure or if serum osmolality increased
– Barbiturates – causes decrease in metabolism and ICP. Causes reduction in cerebral edema and blood flow to brain.
– Skeletal muscle paralyzers may be used (Pavulon)
– Antiseizure drugs – Dilantin
– Loop diuretics – reduce blood volume and tissue volume
- Fluid balance is controversial
– Give saline either .45% or normal saline – not glucose to help prevent additional cerebral edema
– Watch sodium if on Mannitol – may need to give additional salt.
– Also may need additional free water if dehydrated – watch I and O closely.
- Airway and respiratory – suction only as needed and for 10 seconds at a time, only 2 passes. Give 100% O2 prior to suctioning.
– Avoid abdominal distention – may need NG tube to decompress stomach
– Sedate with care – if not on a ventilator, use sedation that will not interfere with respiration or mask any neuro changes
* Posture and head position
• Avoid jugular vein compression
– Head should be in neutral position
– Cervical collars should not be too tight
• Elevation of the head and trunk may improve jugular venous return.
– Keep head in alignment to prevent cutting off venous flow from the head
– Don’t elevate knees – this will increase intrathoracic pressure
– Turn gently from side to side – if turning raises ICP, client will need to stay on back
– If client is posturing frequently during care, will need to sedate first and then do only one thing at a time. Minimize stimulation
– These clients can become agitated and aggressive – avoid over stimulating them
– Restraining them will make them MORE AGITATED and RAISE THEIR ICP!
– NO TV IN ROOM
– Keep room darkened if needed
– Hyperventilation (PaCO2 < 35 mmHg) works by decreasing blood flow and should be reserved for emergency treatment and only for brief periods
– May need eye drops to moisten eyes
– Client may benefit from rehab to help him adapt and progress
– Keep body temperature within normal limits
– Do not use ice on client
– Prevent infection
– Protect from injury
– Avoid factors that increase ICP
– Psychological support