FINAL EM neuro emergencies Flashcards
closed head MOI
coup (primary impact) ie bat hits head
Countrecoup (secondary impact) ie brain shifts back and hits posterior skull
overview ICU monitoring including IVF (iv fluid) details
IVF
- NS v LR (NS preferred bc more Na than LR, 154 v 130)
Rate, tube feedings
Type of sedation: propofol, fentanyl, morphine (propofol good bc CNS protected and short acting)
BIZ monitoring (mini EEG)
Ventilator
Central and A line (central in subclavian vein, Arterial usually in radial artery)
etc
most important parameter for brain function and survival? corresponding relationships
CBF
CBF is related to BP, ICP, CPP and CVR (cerebrovascular resistance)
*CBF to CMRO2 (cerebral metabolic rate of oxygen) important but hard to measure
CBF can be too high - HYPEREMIA in cerebrum
CPP equation, normal, relationship to CBF and ICP
aka cerebral perfusion pressure
CPP = MAP - ICP
Normal >50 in adult
*due to cerebral autoreguation, CPP would need to drop below 40 to impair CBF)
Higher CPP is not protective against ICP (ie higher MAP not protective against high ICP??)
**normal ICP, don’t need pressors for CPP <60
Monroe Kelly doctrin
- blood
- brain
- csf
these are in confined area (skull). Displacement (ie increase in one) can result in herniation
How do you lower ICP
osmotic diuretic ie mannitol
Hypertonic saline
?hyperventilation
Normal ICP values? what happens when ICP increases
adult <10-15
kid: 3-7
infant 1.5-6
*increasing ICP eventually causes herniation
- arterial pressure displaced, CPP will decrease, diffuse cerebral ischemia occurs
- at pressure equal to MAP, arterial blood cant enter skull
(down push = up push = no mvmt blood up)
what herniations may occur
UNCAL = most common
- CN3 compression (blown pupil), trauma
- remember CN3 does pupil dilation and constriction and more
Central - brain stem, global swelling
Transtentorial
Subfalcine
Neurological Examination
• Glascow Coma Scale
– Mild CHI: GCS > 13
– Moderate CHI 9-13
– Severe CHI < 9
– Brain death: 3
– Intubation: Verbal - T • Equals one – Aphasia: Verbal - A • Equals one `
what is the GCS score system
Eye opening (4) 4 = Spontaneous 3 = To voice 2 = To pain 1 = none
Best motor Response 6) 6 = Commands 5 = Localizes 4 = Withdraws 3 = Decorticate 2 = Decerebrate 1 = None
Best verbal Response (5) 5 = Oriented 4 = Disoriented 3 = Inappropriate words 2 = Incomprehensible words 1 = none
Total Score M 6 V 5 E 4
Intubation - T
Aphasic - A
score 3-15
describe decorticate from decerebrate.. which is worse
worst = decerebrate (extensor) due to lesion in corticospinal tract pons or upper medulla
Decorticate (hands to body flexion) due to lesion in corticospinal tract from cortex in midbrain
*better bc higher up
Observation.. important points
head
- laceration
- basilar fx (raccoon, periorbital ecchymoses, battles sign or ecchymosis behind ear, hemotympanum, CSF leak rhinorrhea or otorrhea)
Neck: tender, can you clear C spin
component of neuro exam
Oculomotor nerve (blow pupil if >6 or 4-6 with NR)
MAE (move all extremities)
CN
Corneal (CNV1, CN7)
Cough/gag (CN IX, X)
Dolls eyes/caloric (CN 8,3,4,6)
Pupils
CSF leak
Sensory (unresponsive, try noxious stimulus ie sternal rub), Dyesthesia
Hoffmans and reflexes
what pt needs intubation
GCS 8. 9, 10?? not sure
what is hoffmans sign
reflects presence of an upper motor neuron lesion from spinal cord compression;
- is elicited by flipping either the volar or dorsal surfaces of the middle finger and observing the reflex contration of the thumb and index
finger
normally shouldn’t have response
what are the CN
Cranial Nerves • Olfactory • Optic – VF • Ocular motor – EOM – Ciliary muscle • Trochlear – S. Oblique - SO4 • Trigeminal – V 1 2 3 • Abducens – L. Rectus - LR6 • Facial – Symmetry – Brow vs face • Auditory • Glossopharyngeal • Vagus • Accessory • Hypoglossal
UE and LE components of neuro exm
Neurological exam • Upper and Lower Extremity – 1/5 Flicker – 2/5 movement with gravity eliminated – 3/5 movement against gravity – 4/5 weakness – 5/5 complete
Neuro exam: Reflexes
• Reflexes
– Clonus
– Babinski or plantar reflex
– Hoffmans
Babinski: Indicates some type of motor neuron lesion. Up going great toe abnormal
Hoffmans: Sensitive to spinal cord injury. Flick second digit and look for thumb flicker
Neuro exam: sensation and cerebellar/proprioception/drift
• Sensation – Light touch – Pin prick – Saddle area – Dysesthesia
• Proprioception • Drift • Cerebellar – Romburg – Finger – nose / heel – shin – RAM
Important Dx studies for neuro exam
Diagnostic Studies • Type and crossmatch • CBC (Platelets, anemia, h and h) • BMP (electrolytes esp Na/K) • Osmolality • Toxicology screen • Blood alcohol level (BAL) • INR/PT/PTT (Make sure INR Is not elevated. To reverse elevated INR can get PCC. Or can give factor 7 or FFP) • CT/MR (brain, C/T/L spine)
**factors 2 7 9 10 need vitamin… Vitamin K
How should we approach Radiology and anatomy re neuro dx
what are we looking for
blood, think density (acute/chronic, subacute, hyperacute)
- acute blood = dense = white
- older blood = darker
- bone and blood bright; csf and air dark
Type of blood (density) helps us determine severity
Location
Cisterns
What types of hemorrhages can occur
Intra axial:
- Intracerebral hematoma (IPH) (bruise in brain)
- Diffuse axonal injury (small injuries)
Extra axial: SAH, SDH, EDH
Intraventricular hematoma
Intraparenchymal
What is a Diffuse Axonal Injury (DAI)? best imaging/tx
*intra axial hemorrhage
2nd most common TBI
Multiple lesions
*acceleration and deceleration rotation inury shearing axons
Iceberg concept* microscopic hemorrhages
**axon disruption - swelling- cell death
MR >CT: look for GW matter junction, corpus callosum, Brainstem, thalamus
- no surg, variable presentation and prognosis
- can be devastating
Extra axial Hemorrhage: SDH (features, physiology, s/sx, tx)
Typical pt: Elderly • Coagulopathy – Check PT/PTT • Brain atrophy – Tear bridging Veins on stretch due to Traumatic or spontaneous (Majority are falls)
Imaging
• CT shows crescent shape
Rapid or slow onset sx
– Acute: sxs 24 hrs
– Subacute: sxs 2d-2wk
– Chronic: sxs after two weeks
TX
• Craniotomy, burr hole craniotomy, or observation
Extra axial hemorrhage: EDH (features, physiology, s/sx, tx)
• Young adult • Healthy • Little or no brain atrophy • Traumatic only – Skull fracture • Arterial • 75% in temporal-parietal area – Middle meningeal artery is the usual culprit • CT shows lens shape held by attached dura • Acute onset and lucid intervals
Tx
• Craniotomy vs. observation
– Why not a burr hole craniotomy?
Setting:
Guy that gets punched in side of head .. Crack temporal bone and tear middle
meningeal artery
Talk and die pt. We take out these hemorrhages
cause, sx, tx: SAH
Traumatic (usually SAH is due to Trauma)
• Hx, CT, Location
• Tx Traumatic: Supportive
Non - Traumatic (less common)
– Aneurysm/vascular lesion (usually Aneurysm)
– Acute onset of “worst HA”
– NV, weakness, lethargy, confusion, CN palsy,
speech changes, stiff neck or
meningismus, photophobia
– 50% of patients die before reaching the hospital
Treatment: Clipping, Coiling
Traumatic SAH v non traumatic on CT
non traumatic: aneurysm ie blood around brainstem (circle of willis)
Trauma: wisps of blood floating around
Stroke/CVA etiology, risks,
85% ischemic, 15% hemorrhagic (need to know cause for tx)
Hemorrhagic: usually HTN or vascular cause
Risks: HTN #1, smoking, high lipids, alcohol, (antiplt therapy can reduce risk)
EVAL s/sx, CT without contrast (bc if hemorrhage, whole brain would light up)
- CT may or may not show infarct, hyper dense artery
- MRI: diffusion sequence (white)
Tx of stroke/CVA
iv tPA iffff….
>18, stroke within 3 hr
NOT if..
ICH, SAH (clinical), known aneurysm, active internal bleeding, bleeding diathesis, head trauma within 3 mth, SBP >185
MERCI retriever
speech..spared or not in stroke
housed on left side of brain. thus speech spared in right side stroke
if pt has hard time speaking, likely had stroke on Left side
Tx of IC HTN (intracranial HTN)
the basics
- avoid hypoxia
(increases mortality): paO2 >60 or O2 sat >90% - avoid hypoTN:
doubles mortality; keep SBP >90 - Control HTN, hypoTN (MAP>90)
- Pressors preferred over IV fluid boluses in head injuries (once euvolemic)
- IVF: NS +20 mEq KC/L (no LR or hypotonic Na bc impair cerebral compliance)
- Elevate HOB 30-45 (decrease ICP by ^ venous outflow = lower carotid pressure)
- Keep neck straight, and collar loose
- Quiet dark room (avoid catecholamine release bc they increase HR, BP, ICP)
- Prevent hyperglycemia (aggravates cerebral edema) 80-180
- Correct INR
- Plt >75K for ICH pt; Hg >9 (variable)
- CVP 5-7 mmHg
