Elevated ICP Flashcards
What’s normal ICP? When should tx of high ICP start? Formula for CPP?
Normal ICP: below 15
Treatment should start at 20-25
CPP: MAP-ICP (or CVP, whichever is greater)
What are 5 signs and sxs of elevated ICP?
Altered and/or loss of consciousness Dilated or non-reactive pupils Flexor or extensor posturing Nausea and vomiting Headache
Causes of elevated ICP? (6)
Anxiety
Pain
Induction of anesthesia
Increase in CSF due to blockage of circulation or absorption
Increase in blood volume from vasodilation or hematoma
Increased brain tissue 2/2 tumor or edema
Why is an elevated ICP bad?
reduced blood flow to the brain
brain herniation across the meninges, down the spinal canal, or through an opening in the skull
Volatile anesthetics and their effect on CBF and CMR
Volatiles increase CBF, but decrease CMR
What does propofol do to the CMR, CBF, and ICP? what are its affects on MAP?
CMR: Decreases
CBF: Decreases
ICP: Decreases
MAP can be decreased, leading to a decrease in CPP.
What does etomidate do to the CMR, CBF, ICP?
Etom:
CMR: Decreases
CBF: Decreases
ICP: Likely decreases
What do Benzos due to the CMR, CBF, ICP?
Decrease CMR
CBF: Decrease
ICP: May decrease
Opioids and CBF and CMR
minor reduction or no effect on CBF or CM r
Barbituates and CMR, CBF, ICP. What does it do to MAP? What does it do to the EEG?
Decrease CMR
Decrease CBF
Decrease ICP
Can decrease MAP
At high doses, can cause isoelectric EEG and decrease CMR by 50%
Why do you want to avoid Nitrous in elevated ICP? what pain stuff does it have? What does it do to CMR, CBF, ICP? What does it do to the CBF/CMR coupling?
Avoid it because it can have possible neurotoxic effects
It’s a NMDA receptor antagonist
increases CMR
Increases CBF
Increases ICP
Disturbs CBF/CMR coupling in humans receiving sevo
What does ketamine do to CBF and CMR?
Increases both CBF and CMR
What are some indications for ICP monitoring?
GCS less than 8
Abnormal CT findings of hematoma, contusions, edema, or compressed basal cisterns
Severe TBI even with normal head CT IF patient is greater than 40, has motor posturing, and a systolic BP less than 90
Treatment of ICP: Positional Hemodynamics Analgesia? PaO2? CO2? Crit? Temp?
Position: elevate head 30 degrees above heart level, make sure C collar isn’t too tight
-Hemodynamics: Systolic greater than 110 and diastolic greater than 70
Analgesia: adequate sedation and pain control, IV esmolol, narcotics and lidocaine
PaO2? Avoid hypoxemia PaO2 less than 60
CO2? only hyperventilate if the patient has imminent signs of cerebral herniation. Maintain PaO2 at 30-35, with hyperventilation less than 30 only for episodes of elevated ICP that can NOT be controlled by other means.
Crit should be greater than 30
Patients should be normothermic-do not rapidly heat if hypothermic, but do rapidly cool if hyperthermic.
Osmotic therapy: Mannitol-dosing and what do you need to give with it? how does it reduce ICP? what rebound issue is it associated with? For who is it contraindicated/
Which diuretic could you use? who would it be most useful for? what is the dose
What kind of saline could you give for elevated IcP?
dosing of mannitol: 0.25-1.0 g/kg IV over 15-30 min. This reduces ICP by pulling excess interstitial fluid into vascular space-lowering ICP. Maximum effect in 1-2 hours. UOP can exceed 1-2 liters within an hour. Infusion of crystalloid soln is necessary to replace intravascular fluid loss. Mannitol is assocaited with rebound intracranial hypertension, and is contraindicated in patents who are NOT adequately volume resuscitated.
You could also use furosemide-Dose is 1 mg/kg-its useful in patients with increased vascular fluid and pulmonary edema.
You could give hypertonic 3-5% saline for increased ICP
