Neurological Emergencies Flashcards
Define Pia Mater
Thin cerebral cortex cover, Inner most layer
Subarachnoid space
Located between Arachnoid and Pia Mater. Contains CSF
Define Dura Mater
Tough outer covering. (2 layers, outer covering adhesed to skull.)
Epidural space
Potential space between skull and dura mater. (requires high pressure to create bleed, usually arterial and eye shaped on CT scan)
Subdural space
Potential space between dura mater and the arachnoid
Normal ICP
0-10 mmHg
Transducer location for monitoring ICP
Even with the Foramen of Munro (even with ear canal)
Normal CPP
> 60 mmHg
CPP formula
CPP = MAP - ICP
MAP formula
MAP = DBP + 1/3 pulse pressure
Pulse pressure formula
SBP - DBP
S/S of increased ICP
Change in LOC, pupil size and reaction Abnormal motor response Decorticate posturing Decerebrate posturing Cushing's Triad
What is Decorticate posturing?
Adduction of arms towards core.
Indicates damage above cerebellum and brainstem
What is Decerebrate posturing?
Extension and hyperpronation of arms.
Indicates damage to brainstem or compression of thalamus and brainstem
Cushing’s Triad
Hypertension
Bradycardia
Respiratory changes
(Widening pulse pressure)
Treatment of ICP
Position patient (eyes forward with c-collar)
Limit noxious stimuli (suction, noise, pressure change, invasive procedures)
Maintain euvolemia, normothermia, electrolytes
Sedation (benzos, Propofol)
Analgesia (opioids, fentanyl)
NMBA (non-depolarizing)
Subdural Hematoma
Blood between dura and arachnoid layer (usually venous)
3 types of subdural hematoma
Acute = symptomatic within 24 hours Subacute = symptomatic within 2-10 days Chronic = symptomatic after 2 weeks
Subdural hematoma in different age groups
Elderly = larger subdurals with slowly developing symptoms due to cerebral atrophy
Younger = Rapid onset of symptoms with marked increased ICP
Pediatric = Typically occur <18 months, look for bulging fontanelle and retinal hemorrhage
Epidural Hematoma
Bleeding between skull and dura mater (usually arterial)
Laceration of the middle meningeal artery in the temporal lobe
Classical symptom of Epidural hematoma
Transient loss of consciousness followed by lucid period
Define Subarachnoid Hemorrhage
Bleeding between arachnoid membrane and pia mater.
Common causes of subarachnoid hemorrhage
#1 - Trauma #2 - Berri aneurysm (rupture due to HTN)
Classical symptoms of subarachnoid hemorrhage
Worst headache of my life
N/V, stiff neck, vision disturbances, altered LOC
(commonly confused with meningitis, do not do lumbar puncture)
Define Intracerebral hemorrhage
Hemorrhage in the brain parenchyma
Produced from shearing and tensile forces
Frequently occurs in the white matter of the frontal and temporal regions
Define Intraventricular hemorrhage
Bleeding in the ventricles due to trauma
Results from shearing forces
Greatly increased mortality rate