Week 10 - Increased ICP Flashcards
The brain is like a closed boxed with what 3 essential components
- tissue
- blood
- CSF
what intracranial pressure (ICP)
- the pressure exerted bc of the combined total volume of the 3 components in the skull
what is the Monro-Kellie doctrine
- describes how a state of equilibrium is maintained by the volume relationship of the 3 components within the skull
- if the volume of any of the 3 components increases, the volume from another component is displaced so ICP isnt changed
what causes increased ICP (IICP)
- if the volume of any of the 3 components in the skull increases without a corresponding decrease in another component
ex. inflammation, infection, bleeding
what factors influence ICP (6)
changes in:
- BP
- cardiac function
- intra-abdominal and intrathoracic pressure (coughing, sneezing)
- body position
- temp
- blood gasses
what is normal ICP?
<15
what is considered IICP
> 20 mmHg
why is IICP clinically significant
- IICP = decreased CPP = risk of brain ischemia and infarction = poor prognosis and brain damage
what is CPP?
cerebral perfusion pressure
- the pressure needed to ensure adequate brain tissue perfusion
how is CPP calculated
= MAP - ICP
what is considered normal CPP? a CPP less than ___ = cerebral ischemia?
- normal: 70-100 (goal = keep above 70)
- less than 50
how does IICP = decreased CPP
- during IICP the brain becomes so tight and edematous that the vessels are squeezed = inadequate cererbral perfusion
describe the relationship between BP and CPP; what indication does this have in nursing care
- a drop in BP = drop in CPP
= need to monitor BP in addition to ICP and CPP
= meds may be used to increase BP based on SBP goal ordered
sustained increases in ICP =?
- causes brainstem compression and herniation of the brain from one compartment to another
compression of the brainstem d/t herniation impacts? (4)
- respiratory center
- cardiac function
- sucking reflex
- motor function
what is primary injury
- happen at the time of injury
ex. hitting head on rock
what is secondary injury
- happens several hours to days after injury
ex. primary injury leads to IICP
how long is treatment for IICP typically required
- several days to 2 weeks
what may be done for patients w IICP? why?
- may “induce coma” thru use of paralytics, benzos, and narcotics
- this allows the brain to rest = decreased ICP
how does the brain tissue component try to compensate for IICP (2)
- distension of dura
- compression of tissue
how does the blood component on the skull try to compensate for IICP
- vasoconstriction of cerebral vessels
how does CSF try to compensate for IICP (2)
- production slows down
- displaced to spinal column
what are some examples of how the tissue component of ICP can be increased (4)
- cerebral neoplasm
- contusion
- abcess
- cerebral edema
what are some examples of things that cause cerebral edema (3)
- increased CO2
- decreased PaO2 (<50)
- elevated H+ conc. (lactic acid released from low PaO2 = anaerobic metabolism)
due to some of the factors that can cause cerebral edema, what is imp to monitor (2)
- ABGs –> CO2 and O2 lvls
- resp system –> RR, sats, breathing pattern, snoring ?? (=less O2)
what are some signs of IICP (6)
- change in LOC
- change in VS –> Cushing’s triad & changes in body temp
- ocular changes
- decreased motor function
- HA
- vomitting (w/o nausea)
what is the most sensitive and earliest indicator of IICP
- change in LOC
what is cushing’s triad (4)
- increasing systolic P
- widening pulse P
- bradycardia w a full and bounding pulse
- irreg resp. pattern
what ocular changes may be seen w IICP (5)
- ipsilateral dilation
- bilat. dilated, fixed pupils (ominous sign)
- sluggish or no response to light
- inability to move the eye upward
- ptosis of the eyelid
a change in pupil size of ____ means you should notify the physician
- change in 2-3 mm
what changes in motor function may occur w IICP (3)
- contralateral hemiparesis or hemiplegia
- decorticate posturing
- decerebrate posturing
what does decorticate posturing mean?
- d/t disruption of the voluntary motor tracts
- damage to one or both corticospinal tracts
what does decorticate posturing look like?
- internal rotation and adduction of the arms w flexion of the elbows, wrists, and fingers
- extension of legs and internally rotation
- plantar extension of feet
what does decerebrate posturing mean
- more serious damage
- disruption of motor fibres in the midbrain and the upper brainstem
what decerebrate posturing look like
- arms stiffly extended, adducted, and hyperpronated
- hyperextension of legs w plantar flexion of the feet
what are early signs (comp mechanisms intact) of IICP (8)
- altered LOC –> confusion, restless
- unilateral pupil change in size, equality, reactivity
- unilat hemiparesis
- vomitting
- HA
- seizures
- papilledema
- focal findings (speech difficulty, visual disturbances)
what are late signs (compensatory mechanisms failing) of IICP (5)
- decreased LOC –> stupor
- unilat or bilat pupillary changes
- Cushing’s triad
- abnormal motor response –> decorticate or decerebrate posturing
- hyperthermia
what are terminal signs (decompensation) of IICP (6)
- bilat fixed & dilated pupils
- resp arrest
- absence of motor response (flaccid)
- HTN w widened pulse P
- bradycardia
- hyperthermia
what are 2 complications of IICP
- inadequate cerebral perfusion
- cerebral herniation
what diagnostic studies are used to differentiate the many conditions that can cause IICP (5)
- MRI
- CT brain/head (quicker & more accurate than MRI)
- MRA
- CTA
- xray skull or facial bone fractures
when is a CT of the brain/head done r/t neuro problems (??)
- done initially
- then repeated in 24-48 hrs
- and again if further pt decline (ex. decreased LOC, increased ICP)
what other diagnostic studies are used for IICP/neuro (6)
- cerebral angiography (clot? aneurysm?)
- EEG (seizures?)
- ICP measurement
- brain tissue oxygenation measurement via LICOX
- transcranial Doppler (vasopasm? velocity of blood flow)
- LP (obtain CSF determine if infection or blood)
when is ICP typically monitored (2)
- if GCS <8
- abnormal CT or MRI (edema, contusion, hematoma, etc.)
why is ICP monitored
- to guide clinical care when pt has or is at risk of IICP
what is an example of a device used to monitor ICP
- external ventricular drain (EVD) (or just ICP monintor)
what does an EVD do (3)
- determines ICP
- determines CPP
- and can remove/drain CSF to decreased ICP
what is an EVD
- involves insertion of a catheter into ventricle (ventriculostomy) connected to a transducer (which translates the ICP and CPP)
what is included in care for pt on EVD (3)
- bed rest
- potential prophylactic antibiotics d/t risk of infection
- constant positioning of the external transducer relative to the position of the pt’s head to maintain consistent measurements
what are the goals of collab care for IICP
- identify and treat the underlying cause of increased ICP
- support brain function
what is the first step in mngmt of increased ICP
- ensuring adequate oxygenation to support brain frunction
what is involved in care r/t ensuring adequate oxygenation for brai function (3)
- ABGs to guide oxugen therapy
- possible endotracheal tube or tracheostomy
- possible mechanical ventilator
what is the goal PaO2 for IICP
- > 100 mmHg
what med is frequently used to decrease ICP
- Mannitol
what is Mannitol
- an osmotic diuretic given IV that decreases ICP = fluid moves from tissue into vessels
describe how mannitol decreases ICP
- plasma expansion –> decreases hct and blood viscosity = increased cerebral blood flow and O2 delivery
- osmotic effect –> moves fluid from tissues into vessels
what type of IV fluid may be given as part of treatment for IICP
- hypertonic saline
describe the use of corticosteroids for IICP
- used to control edema surrounding tumours and abcesses
- not for diffuse cerebral edema
what are some complications associated w corticosteroids (4)
- hyperglycemia
- increased r/o infections
- GI bleeding
- hyponatremia
pts receiving corticosteroids should also be on ??? why (3)
- antacids, H2RB, PPI to prevent GI ulcers and bleeding
describe the use of barbituates for IICP (3)
- used to reduce cerebral metabolic = decreased ICP
- dampens the effects of environmental stimuli
- reduces cerebral edema
describe the use of antiseizure meds for IICP
ex. dilantin (phenytoin)
- used to prevent seizures bc they cause = increased ICP
- additionally, in pts w head injury they are at a risk of seizures d/t the irritation and stress on the brain
describe nutritional therapy for pts w IICP (6)
- pt in a hypermetabolic and hypercatabolic state = increased need for glucose to provide fuel for brain & burn lots of calories = r/o muscle wasting
- if pt cannot maintain adequate oral intake, may require other means of meeting nutritional requirements (tube feed, TPN, etc.)
- will require feedings for optimal nutrition
- dietician involved
- early feedings (within 5 days of injury) have been shown to improve outcomes
- keep stomach working (empty stomach = r/o ulcers)
what assessments are done w pts w IICP (5)
- glascow coma scale
- neurological assessment
- monitor ICP and CPP
- monitor ABGs
- monitor BP for SBP goal
what 3 areas of focus are include in the GCS
- eye opening
- best verbal response
- best motor response
what is included in neuro assessment for pts w IICP (5)
- pupils (PERRLA)
- motor strength bilat
- can pt follow commands?
- palmar drift
- VS
what does cushing’s triad indicate
- medical emergency
= severe IICP and impending cerebral herniation
how often is neuro and GCS assessment done in pts with IICP in the ICU? step down unit? neuro unit?
- ICU = qh
- step down = q1-4h
- neuro unit = q4-8 hr
what are some things that worsen ICP (10)
- seizure (EEG)
- pain
- irritating issue /noxious stimuli
- fear & anxiety
- fever
- coughing
- straining
- re-bleed
- increase in cerebral edema
- increased BP
what meds may be used to induce hypertension to meet goal SBP
- IV vasopressors
describe the environment for a pt w IICP (4)
- quiet
- dark
- calm, quite voice
- towel over eyes pre surgery
what guides our nursing care
- ICP and CPP
ex. may premedicate for interventions like turning, drsg changes –> also let brain “rest” after interventions
describe pt positioning w IICP (7)
- HOB 30 (prevent hypoxia, enhances resp exchange, decreases cerebral edema)
- neutral neck (to enhance blood flow, prevent venous congestion)
- turn q2-3h with slow gentle movements (rapid changes in position = IICP, avoid pain which = IICP) –> consider ICP before & requires 2-4 people
- caution when turning due to drain in brain, IV, foley etc.
- keep body midline (prevent abdominal and intrathoracic pressure)
- decrease stimuli
- avoid hip flexion (= increased intrabdominal pressure)
describe pt temperature r/t IICP
- keep temp normal or low
- may require cooling blanket
(increased temp = IICP)
describe pt temperature r/t IICP
- keep temp normal or low
- may require cooling blanket
(increased temp = IICP)
describe oxygenation r/t IICP (3)
- keep oxygenation high & prevent hypoxemia
- may require intubation & ventilate
- prevent CO2 from rising
describe CSF drainage r/t IICP
- drain CSF per Dr orders (turn valve)
what supportive care is included for IICP (3)
- tube feeds
- prevention of gastric stress ulcers
- prevent problems associated w immobility
what is an important consideration if a pt is wearing an aspen collar w IICP
- make sure it is not too tight –> ~2 fingers fit (otherwise would impact perfusion and drainage)
- perform collar care q24 hr and PRN
describe nursing care r/t resp. function (7)
- ensure maintenance of patent airway
- position patient so lying on the side (as LOC decreases r/o airway obstruction d/t tongue dropping)
- note any snoring (may indicate obstruction)
- remove accumulated secretions via suction (imp bc if unconscious pt cannot cough)
- possible intubation and ventilation (if cannot maintain patent airway d/t decreased LOC)
- position HOB 30
- monitor ABGS –> appropriate ventilatory support ordered on this basis
what is an important nursing consideration r/t suctioning (3)
- should be less than 10 sec in duration (suctioning can cause changes in PaO2= IICP)
- limit to 2 passes per suction procedure (to avoid accumulative changes in ICP)
- provide O2 before and after
why is it important to prevent abdominal distension in pts w IICP (5)
- can interfere w resp function
- increased intra-abdominal pressure can = IICP by impeding cerebral venous drainage
- prevent vomiting
- prevent aspiration
what are some ways to prevent abdominal distension (2)
- insertion of NG tube to aspirate stomach contents (if no facial or skull fracture)
- insertion of an oral gastric tube if presence of facial or skull fracture
why might sedatives, paralytics, and analgesics be given to pts w IICP? what is a challenge w these?
- to prevent pain, fear, anxiety, etc. from = IICP
- challenge: these meds may alter the neuro state = mask true neuro changes = may be necessary to suspend meds to appropriately assess neuro status
why is it important to monitor fluid and electrolyte balance for IICP
- fluid and electrolyte disturbances may = IICP
- too much fluid = IICP
- additionally, hypovolemia = decreased CPP
what is included in nursing care r/t fluid and electrolyte balance
- monitor fluid accuratelly
- monitor I&O
- monitor weight
- monitor electrolytes (bc diruetics and IV fluid may effect)
- monitor urine output
in particular, what electrolytes should be monitored for IICP (4)
- Na (don’t want too high d/t mannitol, r/o DI and SIADH, r/o cerebral salt wasting)
- K
- osmolality ( dont want too high d/t mannitol, r/o DI and SIADH)
- glucose
why is it imp to monitor urine output w IICP
- IICP = risk of developing DI or SIADH
what are signs of DI
- increased urine output
- dehydration
what is treatment for DI (3)
- IV fluids
- vasopressin
- DDAVP
what are signs of SIADH (4)
- dilutional hyponatremia = increased cerebral edema
- change in LOC
- seizures
- coma
what is cerebral salt wasting
- low Na due to excesssive renal sodium excretion (thru urine output)
- associated w cerebral injury
what is treatment for cerebral salt wasting
- salt tabs
what does supportive care for IICP focus on
- reduce metabolic demands as much as possible to prevent further IICP
what is included in supportive care for IICP (9)
- control fever –> temp q4h, tylenol, determine cause
- monitor for seizures (seizure = IICP) –> prophylactic dilantin
- manage pain (can’t tell us, we assume they have pain) –> narcotic
- decrease stimuli –> dark, quiet enviro, keep pt comfy w pillow
- use ICP to guide care –> turning, mouth care, etc.
- sedatives to let brain relax (turn off/down to see how ICP reacts)
- monitor family visits (loud noise can = IICP)
- allow ICP to return to baseline between necessary nursing activities
- do not cluster nursing care
describe nursing care r/t protection from injury (5)
- least restraint approach (d/t confusion, seizures don’t want them to touch their ICP monitor, etc., r/o self injury) —> reassess need for restraints daily
- assess restrained extremities q2h
- if restraints = more agitation , may need light sedation
- pad side rails
- calm, reassuring approach
describe nursing care r/t psychological care (4)
- anxiety over diagnosis
- competent assured manner
- short, simple explanations (ex. why they are sedated)
- allow family participation in care when possible
- explain what you do when family isnt there
what are some things to avoid r/t IICP (7)
- overstimulation (noise, lots of activity in short time, bright lights)
- avoid flexion of hips
- avoid head turned
- do not keep bed flat
- not treating fever
- not treating pain
- an increase in cerebral metabolism (shivering, seziures, etc.)
list some meds that are used for IICP (12)
- sedatives (decrease cerebral metab)
- analgesics & narcotics (pain & sedation)
- high-dose barbs and/or paralytics in ICU (decrease cerebral metab.)
- antiseizures
- antipyretics (q6h)
- mannitol (decrease cerebral edema and blood visocity)
- nimodipine (for vasospasm)
- corticosteroids (if tumour or abscess, not for diffuse cerebral)
- hypertonic saline (decrease swelling, draw water out of brain tissue)
- stool softener
- H2RB, PPI, antacids (prevent gastric ulcer/bleeding)
- antibiotics
what are some nursing considerations r/t hypertonic saline (3)
- monitor Na
- monitor BP and for fluid overload
- infuse at slow rate
what is an example of a steroid used for brain tumour and IICP
decadron
what are signs of IICP (10)
- IICP increase on monitor
- CPP decrease on monitor
- pt less awake or not as responsive (decreased LOC)
- decrease in motor functioning
- posturing
- pupil dilation, sluggish reaction
- HA
- vomitting w/o nausea
- change in body temp (indicates pressure on pons)
- changes in VS (cushing’s)
what is a craniotomy
- bone flap removal to make room for adaption to decrease ICP
- done under general anasthetic
what are nursing considerations for a pt following a craniotomy (3)
- do not put P on the effected side
- do not turn patient onto side where bone is missing
- helmet for protection
what are complications of uncontrolled IICP (5)
- low CPP (Pressure squeezes vessels and arteries)
- cerebral herniation (often down towards brainstem)
- cushing’s traid (terminal)
- herniation downward thru foramen magnum and compresses medulla = often fatal
- brain death
describe the criteria for brain death
- cerebral cortex has no function or is irreversibly damaged
- coma
- absence of brain stem reflexes
- pt is apneic
- pt organ donor
- very different from being in a persistent vegetative state*
what tests may be done to determine if a pt is “brain dead” (3)
- apneic test
- dolls eye test
- cold caloric test
a nursing diagnosis r/t IICP is risk for ineffective cerebral tissue perfusion. what are some nusing interventions for this (6)
- consult w physician for hemodynamic parameters (ex. BP)
- induce hypertension w vasoconstrictive meds (ex. vasopresson)
- neck neutral position, HOB 30
- monitor determinants of tissue O2 delivery (PaO2, SaO2, hgb, cardiac output)
- monitor neuro status
- monitor I&O to assess effects of diuretic therapy
a nursing diagnosis r.t IICP is risk for disuse syndrome. what are some nursing interventions for this (8)
- position pt to maximize ventilation potential
- remove secretions by suctioning
- chest physical therapy
- turn q2h and with care
- prevent pressure injury risk
- perform passive or assisted ROM
- complete nutriitonal assessment
- determine need for enteral tube feedings
