Ncs Tbi

Front 1

leading causes of TBI

Back 1

falls, motor vehicle crashes, blunt impact, assaults

Front 2

leading cause of TBI at extremes of age (<15 and >65)

Back 2

falls

Front 3

predominant cause of TBI in teens and young adults

Back 3

MVC (motor vehicle collisions)

Front 4

surrogates for cerebral blood flow

Back 4

ICP and CPP

Front 5

Poiseuille's laws

Back 5

CBF proportional to CPP and radius of vessel raised to fourth power and inversely proportional to blood viscosity

Front 6

primary determinant of cbf

Back 6

when autoregulation intact = vessel radius; otherwise, CPP

Front 7

additional volume cranial compartment can accommodate before ICP rises

Back 7

150 cc

Front 8

compensatory mechanisms that allow some volume in cranium before ICP rises

Back 8

low pressure veins collapse, cerebral blood volume decreasse, egress of CSF from cranial to spinal subarachnoid space

Front 9

what is cerebral compliance?

Back 9

change in cerebral volume per unit change in pressure

Front 10

what is cerebral elastance

Back 10

inverse of cerebral compliance

Front 11

TBI and compliance curve

Back 11

TBI patients with intracranial HTN operate on steep portion of compliance curve - small changes in volume associated with large changes in ICP

Front 12

contusions

Back 12

regions of hemorrhagic necrosis due to acceleration/deceleration

Front 13

where are contusions usually observed?

Back 13

gyral crests of orbitofrontal and anterior temporal region

Front 14

what percentage of contusions expand during the first 24 hours of injury?

Back 14

1/3

Front 15

what causes EDH?

Back 15

laceration of MMA, injury to middle meningeal vein, diploic veins or venous sinuses

Front 16

describe an EDH

Back 16

typically lens shaped and do not cross suture lines

Front 17

What causes SDH?

Back 17

rupture of bridging veins

Front 18

describe an SDH

Back 18

crescent-shaped and crosses suture lines

Front 19

What causes SAH in trauma?

Back 19

tearing of small pial vesssels

Front 20

location of blood in SAH due to trauma

Back 20

over cerebral convexities, confined to a few sulci or fissures; may distribute diffusely over cortical surface, basal cisterns, into ventricles

Front 21

regions commonly affected by DAI

Back 21

junction between cortex and WM, WM structures close to midline (corpus callosum, internal capsule), brainstem, cerebellum, corona radiata

Front 22

histologic appearance of DAI

Back 22

axonal swellings from accumulated material due to interrupted axonal transport --> periodic "axonal varicosities" or single point swelling "axonal bulb / retraction ball"

Front 23

hallmark of penetrating TBI

Back 23

cerebral laceration

Front 24

formula for kinetic injury

Back 24

1/2 (mass) (velocity)squared = higher velocity more injury

Front 25

distinguishing features of blast TBI

Back 25

DAI occurs in dose-dependent fashion; malignant cerebral edema occur rapidly, vasospasm occur in up to 50% and may last as long as 1 month, concomitant eye / ear injuries

Front 26

mechanisms of secondary injury in TBI

Back 26

neuronal depolarization, disturbance of ionic homesotasis, glutamate excitotoxicity, generation of NO and O2 free radicals, lipid peroxidation, BBB disruption, secondary hemorrhage, ischemia, cerebral edema, intracranial HTN, mitochondrial dysfunction, axonal disruption, inflammation, apoptosis, necrotic cell death

Front 27

appearance of contusions on CT

Back 27

hypodense regions without macroscopic hemorrhage or mixed-high density lesions if gross hemorrhage present

Front 28

appearance of DAI on CT imaging

Back 28

small punctate foci of hemorrhage but usually unremarkable

Front 29

appearance of DAI on MRI

Back 29

abnormalities on DWI, GE, diffusion tensor sequences

Front 30

appearance of cerebral swelling on CT

Back 30

sulcal effacement, loss of differentiation between gray and WM, compression of ventricles, effacement of basal cisterns

Front 31

vascular injury common in TBI

Back 31

disruption of arterial and venous structures: arterial dissection, aneurysms, fistulae, hemorrhage

Front 32

signs of basilar skull fracture

Back 32

retraoauricular ecchymosis (Battle sign); periorbital ecchymosis (Raccoon's eyes), hemotympanum, CSF otorrhea, CSF rhinorrhea

Front 33

moderate TBI

Back 33

GCS 9-12

Front 34

two classification schemes to categorize TBI

Back 34

Marshall and Rotterdam scores

Front 35

fluid resuscitation in TBI

Back 35

hypertonic saline resuscitation has not demonstrated benefit and resuscitation with albumin may be associated with harm

Front 36

primary goals of therapy in prehospital phase of TBI

Back 36

avoidance and treatment of hypoxia and hypotension

Front 37

DECRA trial (arms of treatment)

Back 37

155 patients, severe diffuse, non penetrating TBI, refractory HTN: decompressive crani vs SOC

Front 38

DECRA trial results

Back 38

despite lower ICP, functional outcome worse in crani group

Front 39

DECRA trial criticism

Back 39

significant difference in patients with unreactive pupils on admission in surgical group (although post hoc analysis found no difference in outcome)

Front 40

BP recommendations in TBI from BTF

Back 40

avoid hypotension (<90mmHg)

Front 41

hypotensioin and effects on TBI

Back 41

a single episode of hypotension associated with 2-fold increase in mortality

Front 42

O2 recommendations in TBI from BTF

Back 42

avoid hypoxia (PaO2<60mmHg or O2sats <90%)

Front 43

BTF recommends when to treat ICP

Back 43

if >20mmHg

Front 44

caveat on treatment of ICP in TBI

Back 44

despite successfully reducing ICP (crani, hypothermia, pharmacological coma) not shown to improve outcome

Front 45

indications for invasive ICP monitoring

Back 45

GCS 8 or less, mass effect on CT; cnosider for normal CT with 2 ormore of: age>40y, posturing, SBP <90mmHg)

Front 46

Ecuador / Bolivia ICP trial

Back 46

2012, multicenter RCT 324 patients - targeted therapyto maintain ICP <20 with invasive monitor not superior to therapy based on clinical examination

Front 47

ICP remains >20mm Hg - what to do

Back 47

CSF drainage; osmotherapy; surger; metabolic therapy; hypothermia; laparotomy; hyperventilation