Peripheral Vascular/cea

Front 1

Unstable angina or current CHF Preoperative Intervention:

Back 1

Coronary Angiography, strongly recommended

Front 2

High risk heart cath Preoperative Intervention:

Back 2

CABG, strongly recommended

Front 3

1 or 2 vessel disease by CATH Preoperative Intervention:

Back 3

PTCA/CABG/risk reducing stratigies--OPTIONAL

Front 4

2-3 risk factors on basic evaluation Preoperative Intervention:

Back 4

Dypridamole thallium scan or Dobutamine stress echocardiography--OPTIONAL

Front 5

>4 risk factors on basic exam or strong positive DTS/DSE results Preoperative Intervention:

Back 5

CATH--Recommended

Front 6

Inability to walk 2 blocks without claudication or cardiac s/s Preoperative Intervention:

Back 6

DTS/DSE--Recommended

Front 7

Anesthetic Management of the Patient with PVD:

Back 7

-Control Stress Response
-Avoid hyper/hypotension
-Avoid hypothermia
-Avoid anemia
-Maintain NSR with controlled rate
-Maximize supply and decrease demand

Front 8

Postoperative Concerns for patient having vascular surgery:

Back 8

-B/P, HR control
-Pain control
-Maintenance of intravascular fluid volumg
-Maintenance of nomrothermia
-Graft occlusion

Front 9

Risk Factors for Hemorrhagic Stroke:

Back 9

-Severe HTN
-Anticoagulation/coagulopathy
-Trauma
-Drug abuse

Front 10

Risk Factors for Ischemic Stroke:

Back 10

-Decreased blood pressure (systemic hypoperfusion)
-Carotid Disease (Embolism #1 cause of CVA in patients undergoing CEA)
-Heart Disease
-Thrombus

Front 11

Symptoms and severity of stroke depend on:

Back 11

-Adequacy of collateral circulation
-Size & location of insult
-Presence of increased ICP

Front 12

Indications for CEA:

Back 12

-Syptomatic with >70% occlusion
-Asymptomatic with >60% stnosis

Front 13

Flow Principles assoicated with carotid duplex U/S:

Back 13

-U/S is 95% accurate, non-invasive, determines blood flow velocity
-Bernoulli's Law
-Poiseuille's Law
-Transitional Flow
-Turbulant Flow

Front 14

Bernoulli's Law:

Back 14

When solution flows thru a constricted region of a tube the velocity of flow increases and the pressure by the solution on the walls of the tube decreases

Front 15

Poiseuille's Law:

Back 15

-Laminar Flow, molecules at center of tube encounter least force and move at greater velocity (F=pressure gradient x 4th power of radius/viscosity x length; decrease the radius of a vessel by 1/2 then decrease flow by 16x)
-The 4th power of the radius has the most dramatic effect of flow

Front 16

Turbulent Flow:

Back 16

-Molecules of a solution are in a rough, tumbling pattern encountering the walls of the tube
-Flow becomes turbulent when: velocity is high, tube wall is rough, increased density of solution, change in tube diameter, kinks/bends in system

Front 17

Transitional Flow:

Back 17

Mixture of laminar and turbulent flow, occurs at branch points

Front 18

External Carotid Artery perfuses:

Back 18

-Facial artery
-Occipital artery
-Maxillary artery
-Lingual artery
-Superficial temporal artery
-Superior thyroid artery

Front 19

Internal Carotid Artery perfuses:

Back 19

-Middle cerebral artery
-Anterior cerebral artery
-Ophthalmic artery

Front 20

Neurophysiology Regulation of Cerebral Blood Flow:

Back 20

-Cerebral Perfusion Pressure
-Cerebral Vascular Autoregulation
-Carbon Dioxide
-Hypothermia

Front 21

Cerebral Perfusion Pressure (CPP):

Back 21

-CPP=MAP-ICP
-Normal CPP = 80-100mmHg
-Normal Cerebral blood flow 50ml/100gm/min tissue
-CPP mainly dependent on MAP
-Slowing of EEG at CPP of 50mmHg
-Flat EEG at CPP of 25mmHg

Front 22

Cerebral Vascular Autoregulation:

Back 22

-Cerebral vascular dilates in presence of systemic hypotension
-Cerebral vascular constricts in presence of systemic HTN
-Cerebral autoregulation occurs between MAP 60-160mmHg

Front 23

Effects of CO2 on Cerebral Blood Flow:

Back 23

-Increased PaCO2 causes cerebral vascular dilation
-Decreased PaCO2 causes cerebral vascular constriction

Front 24

Hypothermia effect on Cerebral Blood Flow:

Back 24

-Cerebral blood flow changes 5-7% per degree Celsius
-hypothermia decreases both cerebral metabolic rate and cerebral blood flow
-Maintain mild hypothermia 33-35 degree for CEA

Front 25

Intraoperative Monitoring during CEA:

Back 25

-Standard Monitors
-Arterial Line
-EEG monitoring
-SSEP monitoring
-Stump pressures
-Transcranial doppler U/S
-IV/Intracarotid injection of xenon
-BIS
-Cerebral oximetry
-Awake patient

Front 26

Electroencephalographic monitoring (EEG)

Back 26

gold standard, measures cortical structure integrity for GLOBAL ISCHEMIA,allows for selective shunting
-not great for focal ischemia, affected by anesthetic depth, expensive, tech to monitor, false +/-, no studies demonstrate decreases morbidity/mortality

Front 27

SSEP monitoring:

Back 27

monitors response of sensory cortex to electrical stimulation, posterior tibial nerve measures latency and amplitude
-controversial in how sensitive test is to measure ischemia, effected by anesthesia, no degree of increased latency or decreased amplitude that is indicitve of ischemia

Front 28

Stump pressures:

Back 28

measures back pressure from flow thru circle of Willis via contralateral carotid and veretebral arteries, cheap & easy
-critical low stump pressures unknown, 60mmHg is what want but <60mmHg doesn't mean perfusion inadequate, false +/-

Front 29

Transcranial doppler U/S:

Back 29

continous measurement of mean cerebral blood flow velocity, detects emboli that decrease blood flow and can give heparin/shunt
-probes on head, no studies,

Front 30

Intravenous or intracarotid injection of xenon:

Back 30

-measures cerebral blood flow before, during, after CEA by injecting Xenon and measure levels in brain with probes on head to see adequate blood flow
-expensive, expertise

Front 31

BIS monitoring:

Back 31

indirectly monitor cerebral blood flow by measuring cortical response, if constant level of anesthesia and suddenly decreased BIS then question event

Front 32

Cerebral oximetry:

Back 32

evaluates cerebral perfusion, measures O2 to cortex indirectly with sensors on head
-variabiltiy with this, no correlation between this and cerebral ischemia

Front 33

Deep and superficial cervical plexus block:

Back 33

Blocks C2-C4, may get ipsilateral phrenic nerve paralysis

Front 34

Cranial Nerve VII:

Back 34

Facial nerve, assess by smile/frown

Front 35

Cranial Nerve IX:

Back 35

Glossopharyngeal, assess by swallowing

Front 36

Cranial Nerve X:

Back 36

Vagus, controls laryngeal muscles, assess by speech;
say "e" means vocal cords closing correctly-RLN intact

Front 37

Cranial Nerve XII:

Back 37

Hypoglossal, assess by stick out tongue and move side to side

Front 38

Postoperative Complications after CEA:

Back 38

-Respiratory insufficiency
-Carotid body dysfunction
-RLN/SLN damage
-Hypertension
-Hypotension
-Pneumothorax
-Hematoma
-Hyperperfusion syndrome
-Postoperative stroke

Front 39

Hyperperfusion syndrome:

Back 39

-Associated with uncontrolled HTN, 2nd CEA, anticoagulation
-Unknown cause, increased blood flow as a r/o loss of cerebral autoregulation from cerebral ischemia, may be cushing reflex-output of catecholamines
-S/S: increased ICP, vision changes, h/a, seizures, ALOC, CVA, loss of motor control