head trauma Flashcards
what is the primary injury in head trauma?
what occurs at the scene, damage is irreversible, may be focal or diffuse, and treat the consequences
What are the secondary injuries in head trauma?
occur any time after primary event; potentially prevetable, inflammation, reperfusion, superoxide production, necrosis, apoptosis
Greatest negative affect in head injuries?
decreased oxygen
30% of patients are hypoxic on admission for head injuries d/t what 2 causes?
central resp depression, chest injuries
What 2 things do you consider first in head injuries?
hypoxia and shock
What should you do first in a head injury pt before sedation and paralytics?
baseline neuro exam
Signs of compression of oculomotor nerve?
dilation and sluggish response
Indication of uncal herniation?
maximally dilated and blown pupil
6 positive findings on CT scan?
midline shift, distortion of ventricle and cisterns, effacement of sulci in uninjured hemisphere, presence of hematoma in any location of cranial vault, fractures, intracranial air
Severe head injury requires immediate?
intubation using c spine stabilization and techniques that avoid increasing ICP
Most frequent type of head injury?
scalp laceration
Extensive scalp lacerations can result in?
significant blood loss and air embolism
Head injury that results from a violent shock or jarring?
concussion
5 sx associated w concussion?
transient amnesia, vertigo, nausea, weak pulse, slow respiration
3 types of skull fractures?
open, depressed, basilar
Open fractures include those….?
with deep scalp lacerations and fractures extending in to the sinuses
What does an open skull fracture require w/in 24 hours?
debridement
Linear fractures that occur on the floor of the cranial vault are?
basilar skull fractures
This type of skull fracture requires more force to cause than other fractures?
basilar
4 signs of basilar skull fracture?
blood in sinuses, CSF leak from nose/ears, racoons eyes (periorbital ecchymosis), battle’s sign (retroaricular ecchymosis or bruising over the mastoid process)
Highest mortality rate and most common of all cranial lesions?
subdural hematoma
Where is subdural hematoma located?
between brain and dura
Subdural hematoma usually caused by?
accel decel
Shape of subdural hematoma?
crescent
Treatment of subdural hematoma?
immediate surgical decompression
What shape and where is an epidural hematoma?
biconvex and located between dura and skull
Usual cause of epidural hematoma?
torn middle meningeal injury
5 sx of epidural hematoma?
HA, vomiting, seizure, HTN, difficulty breathing
What is characteristic of epidural hematomas?
have brief LOC followed by periods of lucidness. often walk and die though
Treatment for small epidural hematoma w no pressure on brain?
observation
Deterioration of neuro status is sx of this?
cerebral hematoma
Cerebral hematoma presence on CT often delayed for how long?
24-48 hours
3 determinants of cerebral hematoma pt outcome?
cerebral hypoxia, GCS, hematoma volume
Caused by sudden decel or rotational forces that most often occur at gray white matter junction?
diffuse axonal injury
Best diagnostic tests for diffuse axonal injury?
MRI
DAI causes downstream deafferentation and disconnection in the brain stem which leads to?
coma
Sx of DAI?
immediate loss of conscious, most have no period of lucidity
Most frequent cause of persistent vegetative state following trauma?
DAI
CPP is?
difference between MAP and ICP or CPV, whichever is highest
normal upper limit of ICP?
10-15
ICP monitoring is recommended in?
all pts with GCS
6 sx of increased ICP?
HA, vomiting, papilledema, drowsiness, LOC, behavioral changes
Cushing’s reflex?
HTN, bradycardia, irregular respirations
Cushing’s reflex is probably due to?
medullary ischemia
Methods to decrease ICP via CSF?
mannitol, drain, hypertonic solution
Methods to decrease ICP via brain?
mannitol, hypertonic sltn, lasix, decompressive craniectomy, resection of contusion or other mass lesion, blood volume
Methods for controlling ICP via blood volume?
mannitol, hyperventilation, hypothermia, head elevation, neutral neck position, deep prop or barb sedation/paralysis, control of seizures
Brain receives what % of CO?
15
CBF remains constant d/t adjustment of?
cerebral vascular resistance
3 things that abolish autoregulation?
trauma, certain anesthetics, hypoxia
is CO2 a dilator or constrictor?
dilator
Doubling PaCO2 does what to blood flow?
doubles
Why is BP exceeding that of autoregulation bad?
can cause disruption of BBB and lead to cerebral edema
4 components of resuscitation of head trauma pts?
hyperventilation, secure the airway, diuretics, intravascular volume expansion
etomidate dose for head trauma?
0.2-0.3 mg/kg
lido dose for head trauma
1.5 mg/kg
What gas do you avoid in head trauma pts?
nitrous
Goal for CPP and MAP in head trauma pts?
60-70; 70-80
how does hypervent reduce ICP?
vasoconstriction reducing blood flow
Brain is rich in what coagulant?
tissue thromboplastin
FFP indicated when INR exceeds what level?
1.4
When should platelets be given to a head trauma pt?
plts
Preferred fluid in head traumas?
hypertonic or isotonic crystalloid
Neurosurgical patients should be hyperventilated until?
dura is open
What do you want the MAP to be in a neurosurgical pt?
at least 80
Why should you avoid nitrous in head pts?
increases CMRO2, ICP, and CBF
