What is Intracranial Pressure?
The cranium has three comparements: 80% the brain, 10% blood and 10% CSF. Intracranial pressure is the pressure exerted within the cranium by these contents.
Pressure usually ranges from 5-15mmHg.
Monro-Kellie hypothesis
The pressure-volume relationship between ICP, volume of CSF, blood, and brain tissue, and cerebral perfusion pressure (CPP) is known as the Monro-Kellie doctrine or the Monro-Kellie hypothesis. If the volume of one component increases, the volume of the o
Increased ICP (The Cascade)
When ICP increases, cerebral vasoconstriction occurs, which reduces cerebral blood and causes ischemia. If ischemia lasts longer than 5 minutes, the result is irreversible brain damage.
ICP is also affected by CO2 and O2 in the blood, increased CO2 or dec
Increased ICP manifestations
Changes in person's
LOC, motor function, speech, vitals and becomes more dramatic as ICP increases.
Location/cause will determine the symptoms.
Later symptoms include decorticate (flexion) and decerebrate (extension) posturing indicate IICP in the patient
Cushing Triad
Cushing's triad is a clinical triad variably defined as having: Irregular respirations (caused by impaired brainstem function) Bradycardia. Systolic hypertension (Widening Pulse Pressure)
Two Major Complications with IICP
Inadequate cerebral perfusion
Cerebral herniation
Early Signs of IICP: Compensatory mechanisms intact
Altered LOC (confusion, restlessness,)
Unilateral pupil change in size, equality, and or reactivity
Alterted respiratory pattern (bradypnea or irregular pattern)
Unilateral hemiparesis (one sided weakness)
Variable signs include: focal findings (e.g speec
Papilledmea
Papilledema (or papilloedema) is optic disc swelling that is caused by increased intracranial pressure. The swelling is usually bilateral and can occur over a period of hours to weeks.
Late signs of Increased ICP: Compensatory mechanisms failing
Decreased LOC (stupor)
Unilateral or bilateral puillary changes: size, equality, and or reactivity(global pressure)
Ineffective breathing pattern (cheyne-stokes respiration)
Abnormal motor response (decorticate or decerebrate posturing)
Variable signs: HT
Terminal signs of Increased ICP (Decompensation)
Coma
Bilaterally fixed and dilated pupils -no reaction to light
Respiratory and cardiac arrest
absence of motor response (flaccid)
Dying
Variable signs: HTN with widened pulse pressure. Bradycardia, hyperthermia
ICP cascade pathophysiology map
Insult to brain -> tissue edema -> Increased ICP -> compression of ventricles -> compression of blood vessels -> decreased cerebral blood flow -> decreased O2 with death of brain cells -> edema around necrotic tissue -> increased ICP with compression of b
Brain Herniation
Brain herniation occurs late in the course of IICP. In an attempt to save the brain tissue, the brain shifts from an area of high pressure to low pressure. One common site of herniation is the foramen magnum (the hole at the base of the brain where the sp
Nursing Diagnosis
Ineffective airway clearance, ineffective tissue perfusion, impaired skin integrity, and self-care deficit
Overall goals for Increased intracranial pressure
ICP normalized, maintain patent airway, normal fluid and electrolyte balance, no complications secondary to immobility
Nursing care IICP
Normothermia
PaO2 maintenance at 100mmHg or greater
ABG analysis guides O2 therapy, may require mechanical ventilation
Tylenol 1000mg every 4-6hr
Cold cloth on body, cooling blanket, lower room temperature
keep person quiet because it generates heat
Drug IICP
Mannitol -seperate IV potent diuretics pulls liters of fluid at a time, causes brain to shrink and calms pressure
Loop diuretics
Corticosteriods -decrease inflammation (Decadrom)
Barbiturates -coma: take over bodily function and induce coma
Antiseizure dr
Nutritional Therapy
Client is in hypermetabolic state and hypercatabolic state, need for glucose (Glucose IV will cause worsening Edema) neutral IV-Saline or lactated ringers. Keep client normovolemic -feeding tube (oral or NG)
Monitor Na + Cl
ICP monitoring
An icp monitoring device is inserted into the skill to assess IICP. This device is used only for patients in the critical care unit. Intracranial pressures are constantly monitored so that immediate treatment can be started before brain damage occurs. Bec