Neuro #1 Flashcards Preview

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Flashcards in Neuro #1 Deck (20)
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1
Q

Pia Mater

A

Thin cerebral cortex cover, similar to the outside of a grape.

2
Q

Arachnoid Membrane

A
  • CSF location = subarachnoid space
  • between arachnoid and Pia matter
  • CSF is created 500 mL every day replaces whole CSF fluid three times a day.
3
Q

Dura matter outermost layer

A

Tough outer covering that is adhered very tightly to skull

  • requires pliers for separation
  • very high pressure is required for bleeding to occur (arterial)
  • causes lenticular shape bleed
4
Q

Dura Matter inner layer

A

Tentorium or tent like structure (the shelf)

  • separates upper brain from lower brain
  • Tentorium Incisure - hole where upper/lower brain (uncus) meets in middle.
5
Q

Two classifications of Head injuries

A
  1. Supratentorial (above) herniation attempting to force upper brain through incisure. Descending herniation. Most common.
    - Uncal Herniation: brain attempting to shift down through Tentorium incisure.
  2. Infratentorial Herniation.
6
Q

Epidural space versus subdural space

A

Epidural space- potential space between the skull and the dura

Subdural Space - potential space between the dura and the arachnoid membrane

7
Q

Monitoring ICP - transducer needs to be even w/

A

Must be even w/ foramen of Munro (Little tube connects the lateral ventricles with the third ventricle then through the aqueduct of Silvius to the fourth ventricle)
-level with ear canal or bony prominence behind ear

8
Q

Cerebral Perfusion Pressure Calculation

A

CPP = MAP - ICP

  • normal ICP 0-10 mmHg
  • goal CPP : >60 mmHg
9
Q

MAP calculation

A

MAP = (SBP + 2(DBP)) / 3

Or

MAP = DBP + 1/3(Pulse Pressure)
Pulse Pressure = SBP - DBP

10
Q

Decorticate posturing indicates:

A

Damage above the cerebellum & brainstem

-supratentorial

11
Q

Decerebrate indicates:

A

Damage to brainstem. Or compression of the thalamus and brain stem.

12
Q

Causes of signs in cushings triad

A

HTN: increased systolic pressure w/ decrease vascular compliance
- defensive mechanism
Bradycardia: pressure on vagus nerve (theorized)
Respiratory changes: blue wire has been cut, not compensatory.

13
Q

Positioning head injury

A

Eyes forward (natural inline position)

  • allows venous drainage of brain.
  • blood drainage from one part of the brain allows drainage from parts that do not easily drain.
  • head turned to R is worse than to the L

HOB 15-30%
-gravity helps evacuate head.

14
Q

Other treatment for head injuries

A
Limit noxious stimulus
-suctioning, invasive procedures
noise - ear plugs even in coma state
Limit atmospheric changes
Keep patient tanked up - dry head injury will not survive
Normothermia
Normal electrolytes
15
Q

Sedation for head injury patients

A

Propofol is best as it wears off quickly

Benzos take longer to wear off.

16
Q

What happens with hypoventilation and head injury patients?

A

Cerebral steal or luxury perfusion

  • vasodilation due to increased co2
  • non-injured areas of brain vasodilate and rob essential blood from injured site.
17
Q

What happens with hyperventilation and head injury patients?

A

Reverse steal or Robin Hood Effect

  • Rob from rich and give to the poor
  • blood vessels leading to injured brain relax and open in attempt to perfuse. Non-injured brain is vasoconstricted to an unhealthy level in attempt to push blood to injured area.
18
Q

Hypertonic solutions to use

A

Mannitol or hypertonic saline

  • assure adequate resuscitation first
  • foley Cath must be in place
  • ideally, CVP pressure should guide use of these drugs.
19
Q

Barbiturate coma

A

Decreases O2 demand

  • minimizes brain function
  • requires neurologist decision
  • complications exist
  • thiopental too short acting
  • Phenobarbital drug of choice
20
Q

Skull to brain

A

Skull => epidural space => Dura matter (outermost Layer) => Tentorium Dura matter (inner layer) => sub dural space => arachnoid membrane => subarachnoid space => Pia matter => brain