Sams Monitoring/Surg Notecards Flashcards
What are the two different classifications of neuro monitoring?
Blood Flow/Metabolic
Name 3 blood flow monitors?
Cerebral oximetry
Transcrania doppler
Jug Bulb Venous O2 saturation
Name 4 nervous system function monitors
EEG SSEP BAEP VEP MEP
What law estimates brain tissue saturation?
Beer–lambert
Beer lambert law devise that detects decreases in CBF in relation to CMRO2?
Cerebral Oximetry Near–Infrared Spectroscopy
Name 5 things that change accuracy of cerebral oximetry
BP PaCO2 Hgb Regional blood flow Scalp O2
Measure NIRS initially when?
Prior to induction
What is your goal in maintaining NIRS during surgery?
75% of baseline
When is NIRS used the most? 2nd most?
Carotid surgery
Cardiac surgery
Normal cerebral venous O2 saturation?
60–80%
Limitation of NIRS?
ONly measures regional oxygenation
What rule says that the depth of tissue being measured by NIRS is directly proportional to the distance between the LED and sensor?
Spatial Resolution
NIRS monitors what lobe?
Frontal
Do electrocautery interfere with NIRS?
Yes
What displays the difference between regional O2 and baseline?
Delta Base
What index quantifies that depth and duration of patient staying under user–define rSO2 limit alarm?
Area Under Curve (AUC)
What is shorthand for NIRS tissue oxygen saturation?
rSO2
What displays the differnce between SpO2 and rSO2?
Delta SpO2
The top number in NIRS is the _ side of the head.
Left
Trancranial doppler ultrasonography measures _____ not ______.
Velocity not Volume
Narrowed segments of blood will show increased ________ even though there is lower volume of blood traversing.
Velocity
TC Doppler is MOST commonly positioned over the _______ to monitor the ______.
Temporal Bone
MCA
Would increased temporal bone thickness mess with your doppler?
Yes
Where does the doppler measure blood flow velocity?
Circle of Willis
What monitor provides information regarding flow direction, peak systolic and end–diastolic velocity, flow acceleration time, intensity of pulsatile flow, and detection of microemboli?
Doppler
Doppler on the base of the neck monitors the ____ artery.
Basilar
How much blood flow does the jugular bulb drain from the ipsilateral side?
70%
What is the dominant IJ in most patients? What does it drain?
Right
Cortical blood
What is the non–dominant IJ in most patients? What does it drain?
Left
Subcortical
Where is the jugular bulb accessed?
1cm below and 1cm anterior to the mastoid process.
The jugular bulb is near what sinus?
Sigmoid
SjvO2 monitors for ischemia in patients with increased _____. Maintenance goal percent?
ICP
55–75%
Is the SjvO2 the same bilaterally?
no
SjvO2 less than 55% indicates what 2 things
Inadequate delivery
Excessive consumption
SjvO2 greater than 75% indicates what 2 things?
Hyperemia
Stroke
EEG only monitors what structures?
Cortical (outer 2–3cm)
3 basic components of EEG?
Frequency
Amplitude
Morphology
EEG measures the difference of _____ between groups of neurons
Electrical Potentials
Will ischemia be detected in the subcortex or spinal cord by EEG?
No
List of EEG waves from fastest to slowest?
Gamma Beta Alpha Theta Delta
What is my mnemonic for remembering the EEG waves from high to low?
Go Buy A Truck Dear
_____ waves signal the potential for increased ischemia and ischemic damage
Delta
What wave initially occurs when the brain expereinces ischemia? What increases after that?
Beta
Amplitude
After beta waves and amplitude increase, what waves appear during ischemia?
Theta and Delta
Which style of anesthetic depresses EEG more at equal doses?
Inhalation
Inhalation agents increase the ______ and decrease the _____ of EEG waveforms at low and moderate doses
Increased frequency
Decreased Amplitude
Just like inhalation agents, induction doses of etomidate, propofol, and ketamine cause _____ waves at low and moderate doses?
Beta
Once stage 3 anesthesia is reached, frequency is _____ and amplitude is _______
Frequency lower
Amplitude Higher
Which anesthetic produces no theta and delta waves, just high oscillation waves?
Ketamine
Delta waves are mostly if the patient is very _____
Deep
What type of wave is usually evident at a full anesthetic depth?
Theta waves
Gamma hz?
30–100
Beta Hz?
10–30
Alpha hz?
8–15
Theta hz?
4–8
Delta hz?
0.5–4
Which EEG waves occur with: Heightened perception Learning Problem solving tasks Cognitive processing
Gamma waves
Awake Alert Conscious Thinking Excited
Beta waves
Physically and mentally relaxed waves
Alpha
Creative, insightful, dreaming, meditating, reduced consciousness?
Theta waves
Deep sleep without dreams, loss of bodily awareness, repair?
Delta waves
True or false: Etomidate and prop can cause burst suppression
TRUE
Burst suppression occurs with Iso at ____ MAC.
1.5
Burst suppression occurs with Sevo or Des at _____ MAC.
1.2
Is BIS more predictive with inhalation?
Yes
BIS less than _____ reflects low probability of recall
60
What lobe does BIS look at
Frontal
GA BIS?
40–60
Awake BIS
80–100
Mild/mod sedation BIS?
60–80
Deep hypnotic BIS?
20–40
Burst suppression BIS?
Less than 20
Flat line EEG BIS (lack of brain activity) value?
0
True or False: BIS values under 40 for greater than 5 minutes increases mortality
TRUE
What anesthetic produces falsely high BIS at appropriate levels of anesthesia?
Ketamine
Mechanical stress to brain?
Retraction
Loss of functional intergity of brain?
Transection
Ligation, edema, or vessel damage to the brain causes?
Ischemia
Heat to the brain is caused by?
Cautery
T or F: Anemia, hypothermia, hotn, and positioning affect evoked potentials
TRUE
3 evoked potentials monitor _ function
Sensory
_____ decrease in amplitude or ______ increase in latency is indicative of CNS ischemia?
50% amplitude
10% latency
Positive and neg deflection on EPs are what letter? What number is listed by them?
P
N
Time until response (latency)
Which EP detects localized injury to specific area of the neural axis by assessing cortically generated waves?
SSEP
Can SSEP serve as a non–specific indicator of adequacy of cerebral oxygenation?
Yes
The main purpose of SSEP is to evaluate the integrity of the brain or _________
Spinal cord
SSEP specifically monitors the _______ and ______ tracts of the dorsal lemniscal system.
Cuneatus
Gracilis
The cunateus is more ______, while the gracility is more _______.
Cuneatus = Lateral
Gracilis = Medial
SSEP is altered if brain or ______ spinal cord ischemia occurs
Posterior
Which lemnicscal system monitors the cervical and thoracic regions?
Cuneatus
The fasciculus gracilis measures the _____ and _____ regions
Sacral and Lumbar
SSEPs monitor integrity of the ________ cortex.
Somatosensory
What three sensations does the dorsal lemniscal tract carry?
Discrete Touch
Vibration
Proprioception
Where do the first order neurons synapse with second order neurons in the dorsal lemniscal system?
Nucleous Gracilis/Cuneatus
Where do second order neurons of the dorsal lemniscus system synapse with third order neurons?
Thalamus
SSEP stimulating electrodes are placed ______
Peripherally
Most common 2 nerves for SSEP stimulating electrode?
Posterior Tibial
Median
Backup nerve sites for SSEP stimulating electrodes?
Common Peroneal
Ulnar
Primary SSEP detecting electrodes are on the ______. Secondary recordings are on the _____
Scalp
Spine
Where do you record a nerve itself peripherally for verifying stimulation of SSEPs in the lower extremity?
Iliac Crest
Where do you record a nerve itself peripherally for verifying stimulation of SSEPs in the upper extremity?
ERB’s point
What body part is Erb’s point located
Neck
SSEP latency increases 3ms for every 2 degree ______ in temp
Decrease
________ suppreses SSEP amplitude to 15% of normal
Hyperthermia
Which 2 anesthetics increase SSEP amplitude 2–6x?
Ketamine and Etomidate
With SSEP’s avoid ________ of anesthesia which could be confused for ischemia
Boluses/changes
What CN does BAEP monitor
CN 8 Vestibulocochlear
also for brainstem surg
What evoked potential is least sensitive to anesthesia?
BAEP
The only non–damange factor the increases latency of BAEP?
Hypothermia
What happens to BAEP as temp increases?
Amplitude Increases
Electromyography senses mechanical and thermal damage to what CN?
7 (facial)
Standard of care for acoustic tumor surgery
Electromyography
What CN can electromyography measure
3, 4, 7, 10, 11, 12
What should you avoid when doing electromyography facial nerve monitoring?
Muscle relaxants
____________ monitor optic chasm, optic nerve, retina to occipital cortex?
VEP
Patterned flash VEP’s are used on _____ patients.
Awake
_______ flast VEPS via goggles are contacts are used under anesthesia
Unpatterned
When do you have to cover the contralateral eye for VEPs?
Monocular
_____ are rarely used under anesthesia because stable recordings vary among patients
VEP
MEPs assess the ______ spinal cord and __________ tract.
Anterior
Corticospinal
Volatiles and NMB suppress MEPs. Avoid NMB to a level greater than ____ reduction in height of ulnar nerve response.
70%
Best anesthetic for MEPs?
TIVA (prop, ket, narc)
List the most affected evoked potentials to the least.
VEP>MEP>SSEP>BAEP
MEPs are mostly used during _____ procedures
Spinal
Where is the stimulating electrode placed for MEPs?
Centrally (motor cortex, SC)
Use less than ____ MAC for SSEP or MEP
0.5
What is avoided for MEPs w/ PPM, bladder/spinal stimulator, previous crani, metal in body?
Magnetic stimulation
How to remember anestehtic effects on evoked potentials
Very affected
Moderately affected
Somewhat affected
Barely affected
First compensatory mechanism for increased ICP
CSF absorption or shunt to SC
What occurs initially when volume compensating mechanisms reach exhaustion in skull
Local Ischemia followed by global
What cerebri separates L and R hemisphere?
Falx
What separates the supratentorial and infratentorial space
Tentorium Cerebelli
What type of herniation occurs at the singulate gyrus under the falx cerebri and causes midline shift?
Subfalcine
What type of herniation occurs at the uncinate gyrus through the tentorium cerebelli which causes brainstem compression?
Transtentorial
Altered consciousness, sight and ocular reflex issues, respiratory and cardiac function would b cause when the ______ gyrus goes through the _________
Uncinate
Tentorium
What subtype of transtentorial herniation is associated with oculomotor nerve dysfunction
Uncal
What type of herniation results from increased infratentorial pressure causing extension of cerebellar tonsils through the foramen magnum?
Tonsillar herniation
Tonsilar herniation would cause _______ instability due to pressure on the _______.
Cardiorespiratory
Medulla
_______ or _______ herniation is any area beneath a defect of the skull or going through the skull?
Transcalvarial
External
Gold standard for ICP
Intraventricular (ventriculostomy
Lumbar drainage of CSF in the setting of brain tumore may lead to ____ herniation.
Tonsillar
Does lumbar pressure always reflect brain?
No
Which 2 devices allow monitoring and csf drainage
Lumbar SAC
Ventric
Ventriculostomy is zeroed _____ with the jugular ______ at the level of the ______.
Daily
Foramen
Tragus
Can ventrics be set to only drain when pressure gets to a certain value?
Yes
What type of drain would be used for ICP monitoring for a pituitary surgery with difficult access
Lumbar
The most common complication of ICP monitoring?
Infection
Infection is increased when ICP ismonitored more than ___ days
5
First peak of ICP (P1)
Arterial pulse
Second peak of ICP (P2)
Cerebral Compliance
3rd peak of ICP (P3)?
AV closure, dicrotic notce
P1 is a ____ wave, P2 is a _____ wave, P3 is a _____ wave.
Percussive
Tidal
Dicrotic
Intracranial HTN is when ____ is greater than P1.
P2
______ is the inverse of compliance
Elastance
What is the lundberg A wave?
Plateau wave
Lundberg A waves last up to ___ minutes with an ICP of _____. They indicate increases ________ or decreased _______.
20
20–100
Elastance
Compliance
Lunberg A waves have _______ outcomes due to ____________ ischemia.
Poor, global
What wave would be seen during cushing’s triad?
Lundberg A
Cushing’s triad?
HTN (wide PP)
Bradycardia
Irregular respirations
Sharp brief P2 spikes when ICP is 20–50
Lundberg B
Rhythmic benign short duration spikes when ICP is less than 20
Lundberg C
ICP is treated when it reaches____
20
Primary symptom of IC HTN
HA
When ICP exceeds 30, CBF _____ which can lead to brain herniation vicious cycle
Decreases
3 ways tumors increase ICP
Size
Edema
Obstructed CSF flow
Congenital narrowing of the cerebral aqueduct of sylvius between the 3rd and fourth ventricle
Aqueductal stenosis
Main sx or aqueductal stenosis
Seizure
For aqueductal stenosis, CT or MRI will show enlarged ______ ventricle and normal ____ ventricle due to hydrocephalus
3rd
4th
Treatment for aqueductal stenosis
Ventricular Shunting
Pseudotumor cerebri?
Benign intracranial HTN
Obsese women w/ menstrual irregularities, SLE, PCOD, addison’s or hypoparathyroidism, during pregnancy?
Benign ICH
Acute treatment of benign ICH?
CSF removal
acetazolamide
Corticosteroids
How much CSF do you remove for benign ICH (pressure over 20)
20–40cc
2 symptoms of benign ICH
HA, visual change
Side effect of acetazolamide ICH treatment
Acidemia
Is acetazolamide a good drug for acute benign ICH treatmetn?
No, more chronic
Avoid ____ and _____ when treating benign ICH
Hypoxia and hypercarbia
If a patient has benign ICH w/ lumboperitoneal shunt, what type of anesthsia is avoided?
Spinal (less effective_
Epidural (dangerous)
4 subcompartments of intracranial space
Cellular (surgeon)
CSF (drainage)
Fluid (Osmotics, diuretics, steroids)
Blood (venous and arterial)
Not recommended to remove CSF in patients with risk of ____ or _____ herniation
Transtentorial
Tonsillar
What intracranial subcompartment can we control most during surgery
Venous blood
All volatile agents ______ ICP, CBV, and CBF
Increase
Because volatiles causes systemic vasodilation and increased CBF, what will happen to CPP?
Decreased!
CMRO2 is decreased and autoregulation is impaire around _________ MAC.
1
CMRO2–CBF uncoupling occurs at _____ MAC
0.6–1ish
Order the volatiles that increase CBF from greatest to least?
Des Sevo Iso
What gas increases absorption of CSF
Iso
Volatile agents are _____ in global ischemia
Beneficial
Volatile agents are _______ in focal ischemia due to steal phenomenon
BBad
Iso breaks the rule because it affects CBF the least, but it double CBF if you get to _____ MAC
1.5
True or false: N2O increases CBF and CMRO2
TRUE
N2O doubles CBF at ___ MAC
0.5
What gas causes •Prolongedaccumulation of metabolic breakdown products can lead to megaloblastic anemia,leukopenia, impaired fetal development, and a depressed immune system (inhibitionof methionine synthase co–factor ofvit B12)
N2O
Does N2O impair autoregulation on its own?
NO. Only when with gas
N2O is ___ soluble than nitrogen
More
All agents excepts ketamine ________ CMRO2, CBF, and ICP
Decrease
Good drug for wake up tests
Dex
What induction drug decreases production and enhances absorption of CSF
Etomidate
Why does etomidate maintain CPP better than prop
Less MAP decrease
Most widely used induction agent in neuro anesthesia
Propofol (Seizure suppression)
When is etomidate not your first choice in TBI
Adrenal supression
Do opioids mess with CMRO2, CBF, ICP?
Not too much
Which opioid can activate sizures, decrease MAP and CPP
Alfentanil
Which opioid to not use in neuro surgery because it causes seizure
Meperidine
Large doses of flumazenil cause _____
Seizures
Do benzos reduce CBF, ICP?
Dose dependent
Opioids are mild cerebral ________
Vasoconstrictors
How do you reverse demerol seizures?
Slow narcan
Ketamine won’t increase ICP if given with GABA agonist like prop or midazolam?
TRUE
Is ketamine a good sole agent in neuro
No
Do NDNMB affect brain
No
Does sux increase ICP, CBF, CMRO2?
Yes
What 2 NDNMBs to avoid in neuro
Panc, atracurium
Are sodium NTP and NTG safe in pateitns with abnormal elastance?
NO, avoid
Inhalation agents _____ CBF, IV agents ________ CBF
Increase
Decrease
All anesthetics/opioids ___________ CPP
decrease (or stay the same)
Inhaltion agent ______ ICP, while IV ________
Increase
Decrease
First line goal value of hypocapnea
30–35
2nd line goal of hypocapnea
25-30
Does ICP decrease more when you decrease CO2 below 20?
No
You can’t do hyperventilation and hypocapnea within 24 hours of ________
TBI
When you hyperventilate and decrease PaCO2, CBF returns to it’s starting value after about ______ hours.
8
What alters the concentration of bicarb in the CSF and brain ECF to cause pH to normalize?
Carbonic Anhydrase
Communicate BP goals with _____ prior to surgery.
Surgeon
Clinical improvement of steroids is usually seen within ____ hours.
24 hours
True or false: ICP may not be reduces until 2–3 days after you start steroids?
TRUE
Start steroids _______ hour priop to reduce edema formation and improve conditions
48 hours
Most common dosing for decadron preop
4mg Q6hours
Steroids for TBI patients is _______
Contraindicated
Can you decrease intra–op edema by giving the first dose of steroids on induction
No
Most common and effective osmotic diuretic
Mannitol
Mannitol dose range
0.25–1g/kg over 10–15 minutes
Manittol Removes \_\_\_ ml Decreases ICP in \_\_\_ minutes Max effect \_\_\_\_ hours Duration \_\_\_\_ hours UOP \_\_\_\_\_
100ml 30 2 6 1–2L/hr
True or false: Give mannitol rapidly
False, causes vasodilation and increased ICP
What do you give mannitol with to increase excretion of water from intravascular space and decrease rate of CSF formation
Loop diuretic
When does mannitol make ICP worse?
Ruptured BBB
What type of patient would you give lasix with mannitol
CHF
What metabolic state does mannitol cause
Hypokalemic Hypochloremic metabolic alkalosis
Make sure you monitor ____ when on mannitol
Electrolytes
What % of saline has similar effects on iCP at 2 hours?
3%
You usually give 3% as a infusion, but what dose can you bolus over 5 minutes?
1–2ml/kg
What happens if you raise Na more than ___ meq in 24 hours?
9
Central pontine myelinolysis
Keep serum osmolarity under ________
320
What can be done to manage ICH refractory to other methods because it decreases CMRO2, hyperthermia, and convulsions?
Barbituate Coma
First line therapy for barbituate coma hotn?
Volume followed by pressors
What is high anion–gap metabolic acidosis caused by?
Propofol infusion syndrome
Barbituate coma interferes with neuro eval and causes ________ on EEG
Burst suppression
BG goal
140–180
Injuyred brains often become _____ due to localized hyperglycolysis.
Hypoglycemic
Should patients get tight blood sugar control in acute severe injury?
Nah
Hyperglycemia ______ ischemic insult
Worsens
In TBI, you should only really treat if over 250 or 200 consistently ok?
Ya dog
_______ is best utilized in patietns at high risk of intraop ischemia due to quesitonable efficacy
Mild hypothermia (34–36)
2 risks of controlled hypothermia
Coagulopathy
Dysrhythmia
Esophageal, tympanic, PA, and jugular venous bulb are good for _______ monitor
Deep brain temp
NS osmolarity and side effect
308, hyperchloremic metabolic acidosis
LR osmolarity and side effect
274, can cause cerebral edema by lowering osmolality
Plasma osmolariy
290
You basically want to maintain normovolemia and MAP during surgery ok
OK
UOP goal
0.5–1ml/kg/hr
Maintain Hct above _____
28%
Dextran interferes with ____ function
Platelet
Hetastarch causes dilutional reduction of coagulation factors, inhibiton of platelets and factor ______
8
10–20 degree semilateral table tilt with shoulder roll?
Jannetta position
What position is used for access to posterior parietal and occipatal lobes and lateral posterior fossa?
Axillary (use ax roll to prevent BP injury)
You should avoid neck ____ during surgery.
Flexion
Concorde position?
Prone
Most frequent cause of prone POVL?
Ischemic optic neuropathy (central retinal vessel occlusion)
Wilson frame, low ABP, low Hct, male, obese, long surgery, large volume leads to increased _____ risk
POVL
Why can prone position cause increased bleeding during spine surgery
IVC compression, epidural engorgement
In the sitting position, pressure transducers should be referenced at the ____
External auditory meatus
Macroglossia, quadriplegia, and pneumocephalus are exacerbated by what position
Sitting
1cm difference in height = _________ mmHg change in BP when in the sitting position
0.78
Distance from heart to EAM in sitting position
15cm
CPP should be maintained at _________ in healthy patients in sitting position
60
CPP should be at least ______ in elderly, HTN, CVD, cervical dz, decreased spinal cord perfusion, sustained retractor pressure
70
Chronic HTN cause ______ shift on autoregulation curve
Right
Sustained _______ pressure is an opposing force to blood flow
Retractor
PA cath is used ________.
A–line is used _____.
CVC is used ______.
Rarely
Always
Usually
Complsitting position that occurs secondary to stretching or compression of the cerpinal cord that may warrant the use of SSEP monitoringication of
Unexplained quadriplegia
What is the absolute contraindication to sitting position?
Intracardiac shunt (PFO, VSD)
Unexplained quadriplegia is caused by neck _______
Flexion
Relative contraindication of sitting positions?
Degenerative cervical spine/CVD
What happens during posterior fossa surgeries in the head up position when air enters the supratentorial space? An air pocked in the skull.
Pneumocephalus
Delayed awakening after posterior fossa or supratentorial surgery can be cause by ________
Pneumocephalus
Pneumocephalus dx
Brow up lateral CT/XR
Pneumocephalus treatment?
Drill hole and needle puncture of dura
2 times VAE most commonly occurs
Posterior Fossa
Upper cervical spine
(in sitting position)
40% of ______ patients get VAE
Posterior fossa
12% of ____ pateitns get VAE
Cervical spine
It is a good idea to lower the patient out of the sitting position _________ you take them out of the head holder.
Before
2 most common sources of critical venous air entry
Sigmoid and Sigittal sinus
VAE results from _____ pressure gradient between the operative site and right side of the heart
Negative
Venous pressure at wound level is usually ______
Negative
Most common way VAE travels?
Into pulmonary circulation, diffuses out of alveloi and is exhaled
VAE may collect at the _____________
Cavoatrial junction
VAE will rarely transverse the pulmonary capillaries and enter ________ circulation.
Systemic
What percent of patients have PFO
30%
Paradoxical air embolus occurs when _______ heart pressure exceeds __________
Right, Left
What should you do for patients who have a murmur and are gonna have sitting position
Echo
Avoid the use of ____ in patients with VAE
PEEP
VAE endothelial mediators produce a reflex pulmonary ______.
Vasoconstriction
What causes RV failure and decreased CO in VAE
Air–lock
Obstructed pulmonary blood flow causes what kind of VQ deal
Dead Space Ventilation
Air that enters the PA can trigger reflex ________ and pulmonary ______.
Bronchospasm
Edema
Air in alveoli may be detected by presence of ET _______
Nitrogen
How much VAE causes decreased ETCO2, Increased ETN2, oxygen desaturation, AMS, and wheezing?
Less than 0.5 ml/kg
What amount of VAE causes difficulty breathing, wheezing, hypotension, ST changes, peaked P waves, JVD, MI, bronchonstriction?
0.5–2ml/kg
What amount of VAE cause CP, RV failure, CV collapse, pulmonary edema
Greater than 2ml/kg
Hypotension, tachycardia, dysrhythmia are ______ signs of VAE
Late
Order of sensitivty for VAE detection
TEE Doppler PA/ETCO2 CO/CVP BP, EKG, Precordial detection
Where is the precordial doppler placed for VAE
R sternal border between 3–6th ICS
Late sign of air entrainment on precordial doppler
Mill–wheel
PA cath is slightly more sensitive than ETCO2 when _____ is greater than _______
RAP > PCWP
Doppler can detect as small as ______ml/kg air for VAE
0.002
How to check for proper VAE doppler position
Inject 10ml in CVC and listen
The first sign of VAE for patients on controlled ventilation when they suddenly attempt to breathe spontaneously?
Gasp Reflex
What increases cerebral venous pressure and induces bleeding when treating VAE (good)
Bilateral jugular compression
Position for VAE treatment?
Durrant
Trendelenber, left lateral
50% N2O will ____ an air bubble size
Double
70% N2O will ________ an air bubble size
Quadruple
True or false: PEEP and Valsalva are recommended to treat VAE?
FALSE. They are bad
Durrant position traps air in the __________.
RA
