Week 5: Cerebral dysfunction Flashcards Preview

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Flashcards in Week 5: Cerebral dysfunction Deck (80):
1

Brain uses what for metabolism?

glucose and oxygen

2

Autoregulation is the brains ability to? When does it shut down

  • maintain constant cerebral blood flow 
  • less than 60, greater than 160 systolic, or cerebral perfusion suboptimal

3

Arterial is the ? system in the brain

High Pressure System
Thinner & more fragile
Carotid & Vertebral arteries supply blood to the brain
Circle of Willis: where blood flows up and is able to flow over to the oppposite side 

4

Venous is the ? Pressure System

Low pressure system

  • Lack valves
  • Compress easily with Increase Pressure

5

Cerebral Perfusion Pressure 

  • CPP= MAP –ICP
  • Normally greater than 50
  • Less than 50 indicates loss of autoregulation 

6

Monro Kellie Hypothesis

Changes in the brain volume result in
Increased ICP
(or) decrease in one of the other volumes

7

VIC

Volume brain + Volume of Blood + Volume of CSF + Volume of Lesion

8

Compliance is the attempt to ?

  • Compliance is the attempt to maintain the ICP  between 5-15 mm/hg
  • CSF  displacement
  • CSF reabsorption
  • Venous compression and blood shunting

9

Cerebral Autoregulation helps?

ensure optimal CBF 

10

Decrease in CBF leads to?

  • Ischemia
  • Build-up Lactate (does not cross blood brain Barrier)
  • Ultimately cerebral acidosis 

11

Hyperemia

  • Is increased blood flow to brain.  Causes arterial congestion
  • Luxury Perfusion
  • Progressive vasodilation
  • Increased CBF
  • Loss of Autoregulation: Increased ICP

 

 

12

Conditions That Affect CBF & CBV

Increase CBF/CBV

  • Hypertension
  • Fever
  • Pain
  • Hypercapnia
  • Ischemia
  • Cerebral vasodilation

Decrease CBF/CVP

  • Hypotension
  • Sedation
  • Paralysis
  • Hypocapnia
  • Cerebral edema
  • Decrease CO
  • Cerebral vasoconstriction  

13

Cerebral Spinal Fluid

What percent of volume?

How much volume

Pressure?

functions?

  • Approximately 10% of Cerebral Volume
  • Volume = 150 ml
  • Pressure = 3-13 mm/Hg
  • Functions: Cushion brain & spinal Cord, Stable chemical milieu, Assist in the excretion of toxic waste

14

Confusion
Disorientation differences?

disorientations: agitation and anxiety plus the confusion

15

obtunded

responses are slower

16

stupor

only respond with painful stimuli

17

coma

don't respond to painful stimuli

18

Vowel- TIPPS

Common Reasons for altered LOC

Vowel-Tipps

  • Alcohol
  • Epilepsy
  • Insulin
  • Opiates/drugs
  • Uremia
  • Trauma
  • Temperature
  • Infection
  • Psychogenic
  • Poisin
  • Shock-Stroke

19

Glascow coma scale

  • Looks at eye opening, verbal response, motor response.  
  • Higher the score the higher the function
  • Score less than 9=concern

A image thumb
20

Neuro Checks how often and what?

  • Vital Signs Q15 minutes
  • Glasgow Coma Score Q15 minutes

21

Reasons for pupil abnormalities

  • hypoxia
  • hypothermia
  • orbital trauma
  • pharmacological treatement (atropine)
  • cataract surgery
  • seizures
  • hypotension
  • illegal drug use
  • toxic exposure
  • artificial eye
  • cerebral edema
  • congenital abnormality
  • severe TBI

22

Q image thumb

decerebate

23

Q image thumb

decorticate

24

as intercranial pressure increases what happens to pupils?

  • 1st decrease in one sided response
  • then fixed pupils that are not bilateral or responsive to light.  Usually dilated

 

25

What is a positive Dolls Eyes?

turn the patient and the eyes stay fixed straight.  Head goes sideways and eyes go sideways too

26

Caloric Ice Test negative and positive findings?

  • insert 20 ml of cold water into the ear.  You expect to see the eyes start moving, and then they fix over to the side you put the ice water in.  This would be a normal response and a negative eyes test
  • abnormal response is the eyes staying fixed

27

Cranial Nerve Assessment 

  • Corneal: stick something on cornea, they blink (normal)
  • Gag
  • Swallow
  • Cough

28

Type of breathing assoc with problem:

  • Cheyne-Stokes
  • Cheyne-Stokes variant
  • Central neurogenic hyperventilation
  • Apneustic
  • Ataxic

  • Cheyne-Stokes: large bilateral supratentorial
  • Cheyne-Stokes variant:large unilateral
  • Central neurogenic hyperventilation: large bilateral partial
  • Apneustic: large bilateral midpontine
  • Ataxic: large bilateral posterior fossa

29

S/S of Increased ICP infants, children

 

Infants

  • Bulging fontanel
  • Separated cranial sutures
  • Cracked-pot sign: bang on head, sounds like a hollow pot (extra fluid)
  • Setting-sun sign: eyes are low set and whites are showing above it
  • Positive transillumination 

Children

  • c/o headaches, projectile vomiting, and new seizure onset activity

30

Late signs for infants and children of increased ICP

  • Bradycardia
  • Decreased sensory/motor response
  • Alterations in PERRLA
  • Cheyne –stokes respirations
  • Papilledema
  • Decreased LOC/ Coma

31

Early  Signs  of  ↑ ICP

1. Slight LOC changes ***MOST IMPORTANT****

 

2.  Pupils sluggish / Impaired eye movement

3.  Limb strength changes

 

4.  Headache 

32

ICP Peaks?

48 – 72 hours after injury

33

Cushing’s  Triad:  Signs of ↑ ICP   

Blood Pressure

      -Systolic   BP   Increases

      -Diastolic BP  Decreases

      -Pulse Decreases

Widening Puse Presure

Bradycardia

Might also see cheyne-stokes breathing and elevated temperature

34

Brain Herniation occurs when 

a part of the brain pushes downward inside the skull through the opening that leads into the neck
(Foramen Magnum)

35

Burr holes

Will burr holes in skull to allow pressure to be relived and the fluid will come out through the burr holes

36

How To Minimize Cerebral Edema?

Maintain

  • Cerebral perfusion pressure

            CPP of 50 – 70 mm Hg


  • Prevents Hypoxia (Hypercarbia)

 

 

37

UNCAL Herniation Early, mid, and late

Early herniation (potentially reversible):
-LOC may not be impaired initially


Herniation to the Midbrain/Upper Pons:
-Deep Coma, Dolls eyes, pupils fixed, posturing, hyperventilation, wide pulse pressure

Herniation to the Medulla (Late phase of Uncal Herniation):

  • irreversible (terminal)
  • Deep Coma
  • no pupillary response
  • cluster or apneic
  • pulse pressure starts to narrow again 

38

Lumbar Puncture

Used to diagnose:

  • Meningitis
  • Guillain-Barre syndrome
  • multiple sclerosis
  • Cancers of the brain & spinal cord.

-Insert large bore needle, it's a sterile proceedure.  Keep them laying flat after and watch them for headache (very severe).  If happens, they'll do a blood patch to put fluid back into the space to reduce the headache

39

Ventricular Puncture

Used to remove excess CSF and reduce ICP pressure

40

EEG

Used to:

  • Electrical Activity
  • Identify seizure activity
  • Determine Brain Death

41

Nuclear Brain Scan

Used to

  • Identify brain lesions, encephalitis, and subdural hematomas

42

Encephalography

Used to

  • Identify shifts from midline
  • May show ventricular dilation 

43

Radiography

Used to

  • Show Fractures
  • Suture separation pediatric population
  •  

44

CT Scan

Show Horizontal and Vertical Cross Sections 

45

PET Scan

Used to
Show Blood Volume

46

MRI

Show tissue discrimination 

47

Intercranial monitoring indications

  • Severe Head Injury
  • GCS 3-8 (less than 9)
  • Abnormal Imaging
  • SBP less than 90 mm/hg
  • Subarachnoid hemorrhage
  • Hydrocephalus
  • Brain tumors
  • Stroke
  • meningitis

48

contraindications for ICP

  • Central nervous system infection
  • Coagulation defects
  • Anticoagulant therapy
  • Scalp infection
  • Severe midline shift resulting in ventricular displacement
  • Cerebral edema resulting in ventricular collapse 

49

Intraventricular monitoring advantages and disadvantages

*gold standard*

Advantages

  • Allows for CSF drainage
  • Provides direct measurement of CSF pressure

Disadvantages

  • Most Invasive
  • High risk for infection/ hemorrhage/ infection
  • Contraindicated with coagulopathies

50

subarachnoid advantages/disadvantages

Advantages

  • Less invasive
  • Easy to place
  • Low risk of infection
  • Able to sample CSF
  • Can be used if ventricles are not able to be cannulated 

Disadvantages

  • Unable to drain CSF
  • Decreased accuracy with time
  • Needs frequent recalibration
  • Easy to be obstructed with bone/tissue

51

Intraparenchymal advantages/disadvantages

advantages

  • Easy placement
  • Low risk of infection
  • Highly accurate

disadvantages

  • Unable to drain CSF
  • Needs a separate monitoring system
  • Catheters kink easy
  • Risk of hemorrhage/ infection
  • Can not be re-zeroed

52

Epidural Probe advantages/disadvantages

advantages

  • Easy placement
  • Low risk of infectin 

disadvantages

  • Unable to drain CSF
  • Can not be re-zeroed
  • Accuracy questionable

53

Noninvasive ICP Monitoring

new technique

  • uses special glasses and measures icp, you can also visualize the waveform
  • applies pressure to the eye
  • accurate, safe, easy to use
  • can actually measure one side versus the other
  • Disadvantage is you cannot remove fluids

54

normal icp for adults

normal is 15

55

maintaning ICP

  • Q 1hour Neuro Checks
  • Monitor MAP, ICP, CPP (MAP-ICP)
  • Monitor ICP wave Forms
  • Strict Asepsis
  • Assess ICP site
  • Watch for CSF leaks (ear, see halo with the fluid)
  • Watch for Blood in the ICP monitoring system (should never see blood in there)

56

Never use a ? for ICP monitoring

  • never use a flush device. Use only sterile 0.9% NaCl to fill the pressure tubing.
  • Never use a heparinized solution. 

57

Patients are maintained in a ? head up and neutral position when necessary to minimize the ICP. 

30-45 degree

58

Avoid ? of the neck and positioning the patient in a Trendelenberg position, all of which may increase ICP.  

flexion and hyperextension of the neck

59

simultaneous drainage and pressure monitoring is ?

Simultaneous drainage and pressure monitoring is not recommended. To ensure precise pressure measurements, perform only pressure monitoring while keeping the stopcock closed to the drainage system. 

60

Peak 1

choroidal plexus pulsations: percussion wave

61

peak 2

tidal wave

62

high peaked wave with little differentiation between peak s means?

intercranial pressure is rising

63

peak 3

dicrotic wave

64

ICP monitor level

  • head 30 degrees
  • ear in line with transducer
  • leveler is at 90 degrees (upright)

A image thumb
65

Dampened, absent, distorted waveform potential source and action

potential source

  • Catheter occlusion
  • Air bubbles in system
  • Loose connections
  • Need for recalibration
  • Fiber optic cables broken
  • Kinked tubing
  • Dislodgement of catheter

action

  • Remove any air from system
  • Tighten all connectors
  • Recalibrate and zero
  • Check for kinks
  • Replace transducer, fiber optic device, or monitoring device 

66

ICP values suspect potential source and action

potential source

  • Recalibration and zeroing  needed
  • Catheter/ transducer placement incorrect

action

  • Recalibrate and zero
  • Correct placement of transducer

67

leakage of fluid from tubing potential source and action

potential source

  • Loosened connections 

action

  • Tighten all connectors

68

suctioning with ICP

  • Contraindicated unless necessary: Cough & valsalva increase ICP
  • If required: Be brief, Pre/post oxygenate with 100% FiO2

69

pharmacological interventions for ICP

Osmotic Diuretics

  • Mannitol: Pulls fluid into the cerebral vascular space
  • Reduces cerebral blood viscosity
  • Increases cerebral blood flow
  • Increased cerebral oxygen delivery
  • Dosage: 1.0 gm/kg
  • Nurse considerations: Watch serum osmolality

Pain control: Opioids
Sedatives: Used to reduce cerebral metabolic rate

  • Benzodiazepines
  • Propofol

Paralytics: to decrease workload deman

  • Vecuronium
  • atracuronium

 

 

70

Targeted Temperature Management in ICP

  • Reduces ICP
  • Decrease levels of excitatory neurotransmitters
  • Cerebral edema
  • Free radicals
  • Cerebral metabolic rate
  • 33 degrees celcius

 

 

71

Nursing management of targeted temperature management

Monitor for S/S of:

  • Shivering
  • Arrhythmias
  • Coagulopathies
  • Hypothermia-induced diuresis
  • Electrolyte imbalance
  • Hiccoughs 
  • Rewarming slowly

72

Seizure Precautions

-Seizures are very common with increased ICP

Phenytoin may be initiated with

  • GCS less than 10
  • Cortical Contusions
  • Depressed skull fractures
  • Subdural, epidural and intracerebral hematomas
  • Penetrating head injuries
  • A seizure within the first 24 hours post injury 

Nursing considerations: Safety

  • Oral airway
  • Side rails padded
  • Suction and oxygen set-up
  • Patient/ family teaching
  • Administration and monitoring of pharmacological interventions

73

ALL Cranial Injury things to do?

*ATLS (asvance trauma life support)evaluation & intervention
     (ABCs / Foley / NG / oxygen / Maintain traction)

 

*Constant Monitoring

*Diagnosis:
 
  - CT scan (FAST!)
  - MRI
  - PET Scan (brain function assessment)

 

*Medical interventions depend on severity:

- Endotracheal intubation / hyperventilation
- Sedation
- Diuresis
- Rapid surgical evacuation 

74

Normal pupil reactivity prior to surgery is associated with ?

Normal pupil reactivity prior to surgery is associated with a favorable outcome in 84 -100% of patients

 

75

When both pupils are dilated, outcome?

 

When both pupils are dilated a poor outcome or death occurs in the great majority of individuals

 

76

Postoperative seizures are ? in ICP patients

Postoperative seizures are relatively common in these patients

77

In general, a favorable (functional) outcome is more likely in those patients who are?

In general, a favorable (functional) outcome is more likely in those patients who are treated very soon after injury, those who are younger adults, those with a higher GCS (above GCS of 6 or 7), those with reactive pupils, those without multiple cerebral contusions and those who do not develop difficult to control raised intracranial pressure

 

78

Nursing Interventions for Acute Head Injury

  • Continuous monitoring of Vitals, PERRL and Glasgow Coma Score
  • Report client condition changes ASAP

  • Maintain airway patency- positioning, suctioning (if necessary)
  • Minimize cerebral edema

  • Maximize cerebral perfusion
  • Implement seizure precautions / Siderails

  • Provide emotional support
  • Address all self-care deficits
     

79

how to optimize cerebral perfusion?

  • Keep head position midline
  • HOB elevated ( 30 - 60 degrees )

  • Oxygen ****
  • Sedate prior to activity

  • Minimal ADL movement of client

80

What to teach client and family for ICP?

  • Minimal stimulation environment
  • No coughing, no straining, no hard laughing

  • Head midline + Bedrest + HOB elevated
  • S & S to report to nurse ASAP (Headache, drainage, etc)

  • Purpose + frequency of neuro checks
  • Medication regime (Narcotics, diuretics, stool softeners, etc)

  • Medical interventions (Tests, traction, logrolling, surgery, etc)