TCE

Question 1

what is the classic sign of uncal herniation

Answer 1

ipsilateral pupillary dilation associated with contralateral hemiparesis

Question 2

whats the normal intracranial pressure

Answer 2

10mmHg

pressured >20mmHg, particularly if sustained and refractory to tx, are associate w/ poor outcomes

Question 3

whats the Monro-Kellie doctrine

Answer 3

the total volume of the intracranial contents must remain constant, because the cranium is a rigid, nonexpansible container. Venous blood and CSF may be compressed out of the container, providing a degree of pressure buffering. Thus, very early after injury, a mass such as a blood clot may enlarge while the ICP remains normal. However, once the limit of displacement of CSF and intravascular blood had been reacher, ICP rapidly increases

Question 4

in a clinical setting, how is the cerebral perfusion pressure definer

Answer 4

MAP - ICP

Question 5

what are the clinical signs of basilar skull fracture

Answer 5

periorbital ecchymosis (racoon eyes)
retroauricular ecchymosis (Battle’s sign)
CSF leakege from nose or rear
7th and 8th nerve dysfx (facial paralysis and hearing loss)

Question 6

classification of brain injury according to morphology

Answer 6

skull fractures:

• vault: linear vs stellat, depressed/nondepressed, open/closed
• basilar: w/ or w/o CSF leak. w/ or w/o 7th nerve palsy

intracranial lesions:

• focal: epidural, subdural, intracerebral
• diffuse: concussion, multiple contusions, hypoxic/ischemic injury, axonal injury

Question 7

characteristics of diffuse brain injuries

Answer 7

range from mild concussions to severe hypoxic ischemic injuries

CT scan can seem normal, or the brain may appear diffusely swollen, with loss of the normal gray-white distinction

another diffuse pattern, often seen in high-velocity impact or deceleration injuries, may produce multiple punctate hemorrhages throughout the cerebral hemispheres

Question 8

what kind of brain injuries are epidural hematomas, subdural hematomas, contusions, and intracerebral hematomas

Answer 8

focal brain injuries

Question 9

characteristics of epidural hematomas

Answer 9

uncommon

typically become biconvex or lenticular in shape as they push the adherent dura away from the inner table of the skull

they are most often located in the temporal or temporoparietal region and often result from a tear of the middle meningeal artery are the result of fracture

a lucid interval between time of injury and neurologic deterioration is the classic presentation of an epidural hematoma

Question 10

characteristics of subdural hematomas

Answer 10

more common than epidural hematomas

often develop from the shearing of small surface of bridging blood vessels of the cerebral cortez

more often appear to conform to the contours of the brain

brain damage underlying an acute subdural hematoma is typically much more sever than that associated with epidural hematomas due to the presence of concomitant parenchymal injury

Question 11

characteristics of contusions

Answer 11

fairly common

the majority occure in the frontal and temporal lobes

may evolve to form an intracerebral hematoma or a coalescent contusion with enough mass effect to require immediate surgical evacuation

pt with contusions generally undergo repeat CT scanning to evaluate for changes in the pattern of injury within 24 hrs of the initial scan

Question 12

how is a minor traumatic brain injury defined

Answer 12

by a history of disorientation, amneasia, or transient loss of consciousness in a pt who is conscious and walking

GCS 13 - 15

Question 13

characteristics of a moderate brain injury

Answer 13

pt able to follow simple commands, but usually are confused or somnolent and can have focal neurologic deficits such as hemipareseis

GCS 9 - 12

Question 14

management of a moderate brain injury

Answer 14

CT scan and a follow up CT scan within 24 hrs is recommened if the initial CT scan ir abnormal or if there is deterioration of pts neurologic status
observation and frequent neurologic reassessment for at least the first 12 - 24 hrs

Question 15

characteristics of severe brain injury

Answer 15

pt unable to follow simple commands, even after cardiopulmonary stabilization

GCS 3 - 8

Question 16

management of a severe brain injury

Answer 16

ABCDE's
primary survey and resuscitation
secondary survey and AMPLE history
frecuent neurological reevaluation
admit to a facility capable of definitive neurosurgical care
CT scan

Question 17

What’s an early sign of temporal lobe (uncal) herniation

Answer 17

dilation of the pupil and loss of the pupillary response to light

Question 18

recommended IV solutions when pt has a traumatic brain injury

Answer 18

Ringer’s lactate or normal saline

Question 19

recommended ventilation in a pt that has suffered TBI

Answer 19

hyperventilation should only be used in moderation and for as limited as a period as possible

it is preferable to keep the PaCO2 at approx. 35mmHg

brief periods of hyperventilation (PaCO2 of 25 - 30mmHg) may be necessary for acute neurologic deterioration while other tx are initiated

hyperventilation will lower ICP in a deteriorating pt with expanding intracranial hematoma until emergent craniotomy can be performed

Question 20

recommendations in using mannitol in a pt with a traumatic brain injury

Answer 20

mannitol is used to reduce elevated ICP

preparation most commonly used is 20% solution (20g mannitol / 100ml solution)

should be given to pt with hypotension (b/c it doesn’t lover ICP in hypovolemia and is a potent osmotic diuretic which can further exacerbate hypotension and cerebral ischemia)

strong indicators to admin mannitol in a euvolemic pt:
- acute neurologic deterioration
- development of dilated pupil
- hemiparesis
loss of consciousness
^^^ in this setting a bolus of mannitul (1g/kg) should be given rapidly (over 5 mins) and the pt transported immediately to the CT scanner or directly to the OR

Question 21

preferable solution to use in pt with hypotension in a pt with a traumatic brain injury

Answer 21

hypertonic saline (concentrations of 3% -23.4%)
doesn't act as a diuretic

Question 22

what are the tree main factors linked to a high incidence of late epilepsy

Answer 22

seizures occurring within the 1st week
intracranial hematoma
depressed skull fracture

Question 23

how are seizures treated in an pt with traumatic brain injury

Answer 23

pehytoin and fosphenytoin are the agents generally used in the acute phate

adults: loading dose is 1g of phenytoin given IV at a rate no faster than 50mg/min

usual maintenance dose: 100mg/8hrs, with dose titrated to achieve therapeutic serum levels

diazeoam or lorazepam is frequently used in addition to phenytoin until the seizure stops

control of continious seizured may require general anesthesia

anticonvulsants may also inhibit brain recovery, so they should be used only when absolutely necessary

Question 24

what are the criteria for the dx of brain death

Answer 24

GCS = 3
Nonreactive pupils
Absent brainstem reflexes (oculocephalic, corneal, Doll’s eyes, no gag reflex)
No spontaneous ventilatory effort on formal apnea testing

ancillary studies that may be used to confirm the dx of brain death include:

• ECG: no activity at high gain
• CBF studies: no CBF
• cerebral angiography