Midterm study guide: Neuro Flashcards
Ischemic Stroke: what (two types)
*An ischemic stroke results from an interruption of blood flow to the brain → 2 types (thrombotic & embolic).
*87% of strokes
Thrombotic stroke: Def
*Results from the accumulation of atherosclerotic plaque (fat in the arteries) especially at the bifurcations (curves) of the vessels
Embolic Stroke: Def
Occur when an embolus (blood clot) from the heart or lower circulation lodges in a small vessel resulting in loss of blood supply to the brain
Thrombotic stroke: RF
main one + 4 others
!The greatest risk factor is hypertension!
*Other risk factors: diabetes, smoking, dyslipidemia, CAP
Embolic Stroke: RF
main +3
!The greatest risk factor is A-Fib!
*Other risk factors: Mitral stenosis, valvular issues, endocarditis
Ischemic stroke patho
ischemic or embolic event (something blocks blood supply)→ reduced cerebral blood flow insufficient to maintain neuronal viability (no blood flow = no brain work) → Ischemia occurs (decreased blood flow)→ sustained anoxia (lack of o2) leading to lactic acidosis and high cellular CA → irreversible neuronal cell death (leads to vasoconstriction with elevated BP) → affected brain tissue softens and liquefies (ew)
Ischemic strokes: Characteristic signs
*Sudden onset of focal neurological signs (weakness, visual deficits, paralysis, decreased coordination, facial droop, seizures
*focal stroke is localized to specific area of the brain as opposed to whole brain
Ischemic stroke: Accompanying signs
*Hemiparesis (half paralysis)
*hemianopia (visual fields cut out)
*altered language (aphasia)
Do ischemic stroke pts lose consciousness?
Not usually (unless stroke in brain stem), then will present in a stupor or coma
Confirmation of ischemic stroke
Confirmation of ischemic stroke is the first step because its important for treatment = you give thrombolytics so = you DO NOT want to give thrombolytics in case its hemorrhagic stroke cause then bleeding would just get worse
*GET STAT CT SCAN
IS medical management:
7 points
1: reverse or minimize the cause of the stroke
*Gold standard: thrombolytics: Give rt-PA. 10% over 1 min. 90% over 60 min (this is the thrombolytic)
*give o2: Maintain SPO2 at 95%
*Decrease metabolic requirements: treat high glucose levels, mild sedatives, stool softener
*Maintain cerebral perfusion: treat A-fib with **cardioversion **
*Treat HTN → if not reduced below 185/110 then rt-PA should not be used. **Labetalol (IV) **is an antihypertensive that can be used.
*Give platelet aggregation inhibitors after 24 hours of rt-PA use:
*ASA (aspirin), heparin/lovenox (INR goal 1.7), ticlid/plavix (but not for 24hrs if receiving thrombolitics)
IS management time line
6 points
10 min door to MD → 15 min to neuro consult → 25 min CT scan → 45 min CT interpretation → 60 min give drugs → 3 hrs admit to monitored bed
Hemorrhagic stroke (HS): what
There are subarachnoid hemorrhages (SAH) & there are intracerebral hemorrhages (ICH)
SAH: what
bleeding into the subarachnoid space. Usually caused by rupture of a cerebral aneurysm or arteriovenous malformation
SAH RF (1 main + 3 others)
!HTN!, smoking, ETOH, stimulants (like meth)
SAH: s/s (biggest red flag +4 others + hx)
*“worst headache of my life”
*Accompanied by a brief loss of consciousness, NV, focal neuro deficits
*Also stiff neck!
*Hx: previous episodes of sudden onset of HA and vomiting (these are warning leaks, blood irritates the meninges causing HA, stiff neck, and photophobia)
SAH: Dx (3)
*CT is standard (to check for bleeding)! Will diagnose 95% of cases
*Lumbar puncture used if CT neg but symptoms indicate SAH
*Cerebral angiogram to confirm bleed location and severity
ICH: cause (6)
hypertensive rupture of a cerebral vessel, anticoagulation or fibrinolytic therapy, coagulation disorders, drug abuse, hemorrhage into cerebral infarct or brain tumors
ICH patho (4)
!Elevated BP causes damage! → Arteries rupture → hematoma created → !ICP rises quickly!
ICH s/s: Main + hx +late sign
*Unconscious and need ventilatory support
*hx prior to unconsciousness: HA, N/V, and rapid deterioration
*Late sign: Cushing’s triad
Cushing’s triad
- increased pulse pressure (200-250/100-150, HTN bc the body is wanting to maintain perfusion),
- slow pulse rate (brady bc the body wants to to decrease workload),
- slow, deep, labored resps (cheyne-stokes, body trying to regulate o2)
ICH: Dx (2)
CT scan or an angio for those patients without a clear cause of hemorrhage
ICH: medical management (goal + 4)
!Goal: preserve neuro function!
*support VS specifically BP
*Airway + early diagnosis
*Ventriculostomy drains to decrease ICP
*identify and prevent complications
ICH: complications
!Rebleed!
*accounts for 22% of deaths
It can be the occurrence of a second SAH in an unsecured aneurysm or less commonly in an AVM (spaghetti boyz) (mortality 70%)
ICH: rebleed signs (4)
*Sudden onset or increase in HA
*N/V
*Increased BP
*Changes in respirations
ICH tx: Surgical aneurysm clipping = definitive treatment for preventing rebleeds (what +risks)
*Allows more aggressive treatment
*Taken to the OR within 48 hrs of initial bleed so surgeon can flush out any clots to decrease the risk of vasospasms
*Clip is placed over the neck of the aneurysm to eliminate the area of weakness
*Risk: a clot may break away from the aneurysm during surgery
ICH tx: Surgical AVM excision (spaghetti boys)
*Depends on location and size
*Have to decide between hemorrhaging vs rebleeding
*Done in 2 - 4 stages over 6 - 12 month
ICH tx: Embolization (what, how)
*Is used to secure aneurysm or AVM that is surgically inaccessible
*Under fluoro a catheter is threaded up to the internal carotid artery and then manipulated into the abnormality
*For AVMs: beads or glue sent into vessels feeding the AVM to “clot” it
*For Aneurysms: Placement of one or more detachable coils into an aneurysm to produce a thrombus to also “clot” it
S/S of increased ICP (8)
!earliest and most important is decreased or change in LOC!
*others…
-HA
-Seizures: impaired sensory/motor functions
-posturing: decerebrate, decorticate, flaccid
-decreased motor function
-vomiting
-change in speech
-eye changes
ICP monitoring: Bolt vs EVD
A bolt can only monitor.
An EVD can monitor ICP and treat it by draining CSF from the ventricles.
EVD: Ventriculostomy (5pts)
*Small catheter inserted through a burr hole in nondominant hemisphere into ventricle
*May cause bleeding or edema but CSF can be drained.
*Excellent accuracy.
*Penetrates brain
!never flush as an RN!
Subarachnoid Bolt (5pts)
*Small hollow device placed in subarachnoid or subdural space
*Fair accuracy but needs to be recalibrated frequently
*Cannot drain CSF
*Does not penetrate brain
*Lower chance of infection than EVD (less invasive)
Interpreting ICP waveform:
*Normal ICP: Should look like a stair: P1 largest wave, P2 second, and P3 third
*Increased ICP: P2 is higher than P1
Neuro exam lecture: (5pts)
- Observe: are they awake? talking? breathing? what do you see, VS, IVs, lines? build mental frame work
- Talk to pt: name? (do they respond) try to wake them up. Orientation questions
- GCS: eyes, verbal, motor (best: 15, coma: >8, worst: 3)
- test cranial nerves
- Motor and sensory exam
ICP management: position (3 pts)
*Position:
-HOB individualized to maximize cerebral perfusion.
-no trendelenburg or prone, extreme flexion of the hips
-keep neck in line w/ thorax
ICP management: (watch for ->increase ICP)
*PEEP >20
*coughing, sneezing, valsalva, suctioning
ICP management: hyperventilation
*reduce PaCo2 to 33-37
ICP management: Temp control (2)
*prevent hyperthermia
-antipyretics: tylenol
-cooling devices
ICP management: BP control (2 + what to give for HoTN 5)
*sedatives
*antiHTNs: beta-blockers, nitroprusside, nitroglycerin
*watch for HoTN (give crystalloids, colloids, blood products, dopamine, dobutamine)
ICP management: seizure control (2)
*Meds: Phenytoin, lorazepam
ICP management: drain CSF
Ventriculostomy
