Week 5: Cerebral dysfunction Flashcards
1
Q
Brain uses what for metabolism?
A
glucose and oxygen
2
Q
Autoregulation is the brains ability to? When does it shut down
A
- maintain constant cerebral blood flow
- less than 60, greater than 160 systolic, or cerebral perfusion suboptimal
3
Q
Arterial is the ? system in the brain
A
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
Q
Venous is the ? Pressure System
A
Low pressure system
- Lack valves
- Compress easily with Increase Pressure
5
Q
Cerebral Perfusion Pressure
A
- CPP= MAP –ICP
- Normally greater than 50
- Less than 50 indicates loss of autoregulation
6
Q
Monro Kellie Hypothesis
A
Changes in the brain volume result in
Increased ICP
(or) decrease in one of the other volumes
7
Q
VIC
A
Volume brain + Volume of Blood + Volume of CSF + Volume of Lesion
8
Q
Compliance is the attempt to ?
A
- Compliance is the attempt to maintain the ICP between 5-15 mm/hg
- CSF displacement
- CSF reabsorption
- Venous compression and blood shunting
9
Q
Cerebral Autoregulation helps?
A
ensure optimal CBF
10
Q
Decrease in CBF leads to?
A
- Ischemia
- Build-up Lactate (does not cross blood brain Barrier)
- Ultimately cerebral acidosis
11
Q
Hyperemia
A
- Is increased blood flow to brain. Causes arterial congestion
- Luxury Perfusion
- Progressive vasodilation
- Increased CBF
- Loss of Autoregulation: Increased ICP
12
Q
Conditions That Affect CBF & CBV
A
Increase CBF/CBV
- Hypertension
- Fever
- Pain
- Hypercapnia
- Ischemia
- Cerebral vasodilation
Decrease CBF/CVP
- Hypotension
- Sedation
- Paralysis
- Hypocapnia
- Cerebral edema
- Decrease CO
- Cerebral vasoconstriction
13
Q
Cerebral Spinal Fluid
What percent of volume?
How much volume
Pressure?
functions?
A
- 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
Q
Confusion
Disorientation differences?
A
disorientations: agitation and anxiety plus the confusion
15
Q
obtunded
A
responses are slower
16
Q
stupor
A
only respond with painful stimuli
17
Q
coma
A
don’t respond to painful stimuli
18
Q
Vowel- TIPPS
A
Common Reasons for altered LOC
Vowel-Tipps
- Alcohol
- Epilepsy
- Insulin
- Opiates/drugs
- Uremia
- Trauma
- Temperature
- Infection
- Psychogenic
- Poisin
- Shock-Stroke
19
Q
Glascow coma scale
A
- Looks at eye opening, verbal response, motor response.
- Higher the score the higher the function
- Score less than 9=concern
20
Q
Neuro Checks how often and what?
A
- Vital Signs Q15 minutes
- Glasgow Coma Score Q15 minutes
21
Q
Reasons for pupil abnormalities
A
- 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
A
decerebate
23
Q
A
decorticate
24
Q
as intercranial pressure increases what happens to pupils?
A
- 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)
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
## Footnote
75
When both pupils are dilated, outcome?
## Footnote
When both pupils are dilated a poor outcome or death occurs in the great majority of individuals
## Footnote
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
## Footnote
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)
