Trauma / ICU Flashcards
Types of Herniation (4)
High-output Heart failure + increased head circumference in neonate = what and why?
what do you do about it?
- Vein of galen malformation (venous hypertension + compression of aqueduct of sylivis)
- Cardiac sx = large left-to-right shunting through cerebral AV fistula
- Embolization of cerebral vein
Typical threshold for ICP that can lead to concern and why
at > 20 mmHg, CSF is shiften to spinal subarachnoid space
Equations:
Mean aterial pressure
Central perfusion pressure
Cerebral blood flow
MAP= diastolic BP + 1/3 (SBP-DBP)
CPP = MAP - ICP
CBF = CPP / CVR
What is P1, P2, and P3?
P1 = Percussion wave (represents arterial pulsation)
P2 = tidal wave (represents intracranial compliance)
P3 = dicrotic wave (represents aortic valve closure)
What does this signify?
P2 > P1
decreased intracranial compliance
Trauma patient is unable to move eyes up.
What is this called?
what does it signify?
Perinaud’s phenomenon
injury to superior calliculus
Patient with signs of uncal herniation also develops ipsilateral weakness
What is this called?
what causes this?
name another possible finding
Kernahan’s notch phenomenon:
False-localizing sign due to compression of contralateral cerebral peduncle to tentoral edge
can also rarely have IL CN III weakness
Herniation syndromes:
- Contralateral leg weakness
- pupillary dilation
- Rostrocaudal deterioration
- Duret’s hemorrhages
- diabetes insipidis
- bilateral occpitial infarction
- Decreased LOC + cardiac / respiratory abnormalities
- CL leg weakness = subfalcine herniation (due to compression of ACA)
- Pupillary dilation = Uncal herniation (due to compression of CN III)
- Central / diencephalic herniation
- Rostracaudal deterioration
- duret’s hemorrhages (due to stretching/shearing of basilar perforators)
- DI (due to pituitary stalk shearing)
- Bilateral occipital infarcts (due to PCA compression)
- tonsillar herniation (sx due to compression of lower brain stem and upper cervical cord)
What herniation syndrome does this make you think of?
Duret’s hemorrhages
Central (diencephalic) herniation
Factors that increase risk of herniation in stroke patients
(5)
- hypodensity in > 50% of MCA territory
- early nausea / vomiting
- NIH scale > 20 (left hemisphere)
- NIH scale > 15 (right hemisphere)
- MCA + either ACA or PCA involvement
Conservative (i.e. non medical, non surgical) management for increased ICP
(6)
- Head of bed > 30 degrees
- Head midline
- Pain / Temperature control
- Goal metrics
- ICP <20 mm Hg
- CPP > 60 mm HG
- hyperventilation (goal pCO2 30-35 mmHg)
lab value contraindicating Mannitol for increased ICP
osmolar gap >10
Osmolar gap = Measured osmolality (MO) - calculated osmolality (CO)
CO = (2xNa + (BUN/2.8) + (Glucose / 18) + (ethanol / 3.7))
Glasgow coma scale and threshold for Mild, moderate, and severe injury
Mild = 13-15
Moderate = 9-12
Severe =/<8
What type of injury does this resulf from
DAI of corpus callosum
acceleration / decelleration injury