Closed Head Injuries Flashcards
Why should care be taken not to over ventilate the closed head injury patient?
Low PaCO2 levels may cause excess cerebral vasoconstriction and resultant hypoxemia
What is the mean arterial BP goal in a closed head injury pt?
More than 80 mmHg
What is an uncal herniation? s/sx?
- Herniation of the medial temporal lobe through the falx cerebelli
- Fixed dilated pupil + contralateral motor paralysis
What is a cingulate (subfalcine) herniation?
-Herniation of the parietal lobe through the falx cerebri
What is a transcalvarial herniation?
Herniation of the brain through the calvari
What are the three major parts of the exam in patients with a closed head injury?
- Neuro exam
- Pupil exam
- Level of consciousness
Lens shaped hematoma on brain CT = ?
Epidural
What artery is classically involved in an epidural hematoma?
Middle meningeal
Which brain bleed has a “lucid interval”?
Epidural
What classically causes an epidural hematoma?
Truama
What classically causes a subdural hematoma?
Whiplash like injury
What is the etiology of the bleeding for a subdural hematoma?
Rupture of the bridging veins
Which crosses suture lines: an epidural or subdural hematoma?
Subdural
Crescent shaped bleed on head CT = ?
Subdural
How can you tell the difference between an acute and chronic head bleed on CT?
Acute = hyperdense Chronic = hypodense
Why is an epidural hematoma more acute than a subdural?
Subdural is a venous bleed so slowly progresses, as opposed to the arterial bleed of an epidural hematoma
Where is the bleeding from with subarachnoid bleeds?
Subarachnoid vessels
What does the CT look like with a subarachnoid bleed?
Blood in the CSF
How might a subarachnoid bleed present as opposed to the other types of head bleeds?
meningeal s/sx
What is the etiology of diffuse axonal injury?
Shearing forces on axonal fibers of the white matter tract, such as from a MVC
What is the classic CT description of diffuse axonal injury?
Punctate hemorrhages along the gray-white matter junction
True or false: any skull fracture with overlying laceration is considered an open fracture, and requires IV abx
True
What are the three components of the Cushing’s reflex?
- HTN
- Bradycardia
- Respiratory irregularity
What is a central transtentorial herniation? S/sx?
- Midline lesions of the frontal or temporal lobes with downwards displacement of the brain through the tentorium
- Bilateral pinpoint pupils, bilateral babinski, increased tone
What is an upward transtentorial herniation? S/sx?
- Posterior fossa lesions displaced upward
- pinpoint pupils + cushing’s reflex
What is the GSC score of a concussion?
14-15
What is second impact syndrome?
Rapid onset of cerebral edema and death
What are the general indications to obtain a head CT in pts with head injury?
- GSC less than 15
- Neuro deficits
- anticoagulation issue/meds
What are the new orleans criteria for getting a head CT in trauma pts? (7)
- GSC less than 15 2 hours after injury
- Suspected open or depressed skull fracture
- Basilar skull fracture
- Vomiting more than once
- Retrograde amnesia more than 30 minutes
- Dangerous mechanism
- Age over 65
What defines a dangerous mechanism according to the New Orleans head CT criteria?
Obvious + fall from more than 3 feet or 5 stairs
What is the stabilizing treatment for increased ICP?
- Elevate head of bed
- Hyperventilate
- Mannitol
Mannitol should only be used if the patient is not hypotensive. What can be used instead if they are hypotensive?
Hypertonic saline
What is the goal PaCO2 with hyperventilation of a increased ICP pt?
30-35 mmHg
What do pts who are asymptomatic after a head injury need to be discharged home safely?
Someone to observe them at home
What needs to be done prior to intubating a pt with a head injury?
Neuro exam before paralyzing them
Who should have low thresholds for head imaging?
Elderly and alcoholics
