Anesthesia for Carotid Anesthesia for Carotid EndarterectomyEndarterectomy

Robert Y. Gumnit, MDRobert Y. Gumnit, MD

Director of Clinical EducationDirector of Clinical Education

Burlington Anesthesia AssociatesBurlington Anesthesia Associates

Carotid EndarterectomyCarotid Endarterectomy

• Prophylactic Prophylactic intervention to intervention to prevent cerebral prevent cerebral infarction and infarction and relieve symptoms of relieve symptoms of carotid carotid artherosclerosisartherosclerosis

• Stroke incidence in Stroke incidence in USA- 160/100,000 USA- 160/100,000 peoplepeople

Etiologies of Ischemic StrokeEtiologies of Ischemic Stroke

• Thromboembolism from atherosclerotic Thromboembolism from atherosclerotic large extracranial or intracranial arterieslarge extracranial or intracranial arteries

• Embolism from a cardiac sourceEmbolism from a cardiac source

• Atherosclerotic disease in small Atherosclerotic disease in small cerebral vesselscerebral vessels

Location of Carotid DiseaseLocation of Carotid Disease

• Most likely site is at the Most likely site is at the carotid bifurcation with carotid bifurcation with proximal internal carotid proximal internal carotid involvementinvolvement

• Carotid circulation Carotid circulation supplies 80 to 90% of supplies 80 to 90% of cerebral blood supplycerebral blood supply

• Vertebral circulation Vertebral circulation supplies 10 to 20% of supplies 10 to 20% of cerebral blood supply cerebral blood supply

Distal CirculationDistal Circulation

• Internal carotid Internal carotid contributes to contributes to anterior and middle anterior and middle cerebral arteriescerebral arteries

• 11stst intracranial intracranial branch of ICA is the branch of ICA is the ophthalmic arteryophthalmic artery

Important Anatomic Structures Important Anatomic Structures Near Carotid DissectionNear Carotid Dissection

• Hypoglossal nerveHypoglossal nerve• Vagus NerveVagus Nerve• Recurrent Laryngeal Recurrent Laryngeal

NerveNerve• Mandibular Branch of Mandibular Branch of

Facial NerveFacial Nerve• Important to document Important to document

preoperative neurologic preoperative neurologic examinationexamination

Clinical Presentation of Carotid Clinical Presentation of Carotid DiseaseDisease

• Varies by site of stenosis and distal Varies by site of stenosis and distal embolizationembolization

• Part of a generalized vascular diseasePart of a generalized vascular disease

• Transient Ischemic Event (TIA)/ Transient Ischemic Event (TIA)/ Reversible Ischemic Neurologic Reversible Ischemic Neurologic Deficit(RIND)Deficit(RIND)

Transient Ischemic EventsTransient Ischemic Events

• Sudden onset of focal neurologic deficit Sudden onset of focal neurologic deficit which resolves within 24 hourswhich resolves within 24 hours

• Contralateral motor or sensory deficitsContralateral motor or sensory deficits

• Amaurosis FugaxAmaurosis Fugax

RIND’sRIND’s

• Neurologic dysfunction greater than 24 Neurologic dysfunction greater than 24 hours but less than 2 weekshours but less than 2 weeks

• Important to differentiate between Important to differentiate between carotid disease and posterior vertebro-carotid disease and posterior vertebro-basilar artery diseasebasilar artery disease

Posterior Circulation SymptomsPosterior Circulation Symptoms

• Binocular vision lossBinocular vision loss

• VertigoVertigo

• ““Drop Attacks”Drop Attacks”

Differential Diagnosis of TIADifferential Diagnosis of TIA

• Intracranial massIntracranial mass

• Cardiac Disease- e.g. Atrial Fibrillation, Cardiac Disease- e.g. Atrial Fibrillation, Valvular Heart Disease, Valvular Heart Disease, Cardiomyopathy)Cardiomyopathy)

• Metabolic Encephalopathy/ Metabolic Encephalopathy/ HyperglycemiaHyperglycemia

Risk Factors for Carotid DiseaseRisk Factors for Carotid Disease

• Advanced ageAdvanced age

• HypertensionHypertension

• DiabetesDiabetes

• HyperlipidemiaHyperlipidemia

• Hypercoagulable statesHypercoagulable states

• SmokingSmoking

Diagnostic ImagingDiagnostic Imaging

• Ultrasound- 89% Ultrasound- 89% detection ratedetection rate

• Gold standard is Gold standard is cerebral cerebral angiography but angiography but there is a 1% there is a 1% chance of a chance of a neurologic deficitneurologic deficit

Choice of TherapyChoice of Therapy

• Individualized assessment of stroke risk Individualized assessment of stroke risk weighing medical management versus weighing medical management versus risk of perioperative stroke, death, or risk of perioperative stroke, death, or cardiac eventcardiac event

• Large multicenter trials comparing Large multicenter trials comparing medical versus surgical management medical versus surgical management comparing anti-platelet therapy versus comparing anti-platelet therapy versus surgerysurgery

Summary of Large Clinical TrialsSummary of Large Clinical Trials

• Depending on particular series, patients Depending on particular series, patients with between a minimum of 50% to 70% with between a minimum of 50% to 70% stenosis are candidates with ipsilateral stenosis are candidates with ipsilateral disease and acceptable surgical riskdisease and acceptable surgical risk

• The greater the degree of stenosis, the The greater the degree of stenosis, the greater the difference in outcome greater the difference in outcome statistics compared to medical therapystatistics compared to medical therapy

Preoperative EvaluationPreoperative Evaluation

• Comorbidities including advanced Comorbidities including advanced vascular disease, coronary artery vascular disease, coronary artery disease- leading causes of disease- leading causes of perioperative deathperioperative death

• Testing is useful if the only if results will Testing is useful if the only if results will impact on actual perioperative careimpact on actual perioperative care

Conditions Requiring Some Conditions Requiring Some WorkupWorkup

• Orthostatic hypotensionOrthostatic hypotension

• Coronary artery diseaseCoronary artery disease

• Myocardial infarctionMyocardial infarction

• Congestive heart failureCongestive heart failure

• Dysrhythmias, Implanted pacer, AICD’sDysrhythmias, Implanted pacer, AICD’s

Assessment of Functional Assessment of Functional CapacityCapacity

• DMDM

• Renal InsufficiencyRenal Insufficiency

• Pulmonary diseasePulmonary disease

ACC/AHA GuidelinesACC/AHA Guidelines

• Stepwise approach to risk assessmentStepwise approach to risk assessment

• Functional capacityFunctional capacity

• Major markers: unstable coronary Major markers: unstable coronary syndromes, MI, unstable angina, syndromes, MI, unstable angina, uncompensated CHF, severe valvular uncompensated CHF, severe valvular lesionslesions

Intermediate MarkersIntermediate Markers

• Mild anginaMild angina

• Previous MIPrevious MI

• Compensated CHFCompensated CHF

• DMDM

• Renal InsufficiencyRenal Insufficiency

Minor Clinical PredictorsMinor Clinical Predictors

• Advanced ageAdvanced age• Abnormal EKGAbnormal EKG• Non-sinus rhythmNon-sinus rhythm• Low functional capacityLow functional capacity• History of strokeHistory of stroke• Uncontrolled hypertensionUncontrolled hypertension• Cardiac and Long-term risks are increased in Cardiac and Long-term risks are increased in

patients unable to meet a 4-MET demandpatients unable to meet a 4-MET demand

Surgery Specific RisksSurgery Specific Risks

• ACC/AHA define CEA as an ACC/AHA define CEA as an intermediate risk procedureintermediate risk procedure

• Risk of cardiac death or non-fatal MI Risk of cardiac death or non-fatal MI generally less than 5%generally less than 5%

• If surgery is to be performed in If surgery is to be performed in presence of high risk indicators, ACC presence of high risk indicators, ACC recommends delaying surgical for recommends delaying surgical for further evaluation and treatmentfurther evaluation and treatment

Elective CEA with Intermediate Elective CEA with Intermediate Risk PredictorsRisk Predictors

• Consider functional capacityConsider functional capacity

• Consider non-invasive testingConsider non-invasive testing

Indications for Further TestingIndications for Further Testing

• Exercise tolerance < 4 METSExercise tolerance < 4 METS

• Symptomatic valvular lesionsSymptomatic valvular lesions

• Dilated or Hypertrophic CardiomyopathyDilated or Hypertrophic Cardiomyopathy

• Hemodynamically significant Hemodynamically significant dysrhythmiasdysrhythmias

Simple Conservative ApproachSimple Conservative Approach

• Assume presence of CADAssume presence of CAD

• Treat with medically appropriate therapyTreat with medically appropriate therapy

• Coronary angiography and prophylactic Coronary angiography and prophylactic revascularization has not been shown revascularization has not been shown to reduce cardiac morbidity and should to reduce cardiac morbidity and should only be used in high risk casesonly be used in high risk cases

HypertensionHypertension

• Most treatable preoperative risk factor for Most treatable preoperative risk factor for strokestroke

• Reduced blood pressure decreases Reduced blood pressure decreases probability of perioperative strokeprobability of perioperative stroke

• Poorly controlled BP increases risk of Poorly controlled BP increases risk of perioperative hemodynamic instability and perioperative hemodynamic instability and significant neurologic eventssignificant neurologic events

• BP meds continued right up to time of surgeryBP meds continued right up to time of surgery• Rapid correction of BP preoperatively not Rapid correction of BP preoperatively not

advisedadvised

Delay Surgery if Not EmergentDelay Surgery if Not Emergent

• Uncontrolled hypertensionUncontrolled hypertension

• Uncontrolled diabetesUncontrolled diabetes

• Uncontrolled coronary diseaseUncontrolled coronary disease

Goals of Anesthetic ManagementGoals of Anesthetic Management

• Protect brain and heart Protect brain and heart from ischemic injuryfrom ischemic injury

• Maintain hemodynamic Maintain hemodynamic stabilitystability

• Ablate stimulatory and Ablate stimulatory and stress response to stress response to surgerysurgery

• Awake, cooperative Awake, cooperative patient at end of patient at end of procedure allowing procedure allowing clear neurologic clear neurologic evaluationevaluation

Standard MonitoringStandard Monitoring

• ECG- Leads II, V4-5 for rhythm and S-T ECG- Leads II, V4-5 for rhythm and S-T segmentssegments

• Continuous arterial pressure monitoring, Continuous arterial pressure monitoring, arterial linearterial line

• Pulse oximetryPulse oximetry

• Central lines generally not necessary Central lines generally not necessary but should not be placed in jugular areabut should not be placed in jugular area

Perioperative Perioperative ß-Blockadeß-Blockade

• Continue for patients already on this Continue for patients already on this therapytherapy

• Those who are not already on Those who are not already on ß-ß-blockers can be started on them blockers can be started on them immediately if there is no immediately if there is no contraindication for reduction of contraindication for reduction of perioperative myocardial ischemiaperioperative myocardial ischemia

Choice of Anesthetic TechniqueChoice of Anesthetic Technique

• Largely dependent on preferences of:Largely dependent on preferences of:

1.1. SurgeonSurgeon

2.2. PatientPatient

3.3. Anesthesia TeamAnesthesia Team

• No strong data to clearly mandate any No strong data to clearly mandate any particular method or agentsparticular method or agents

General Anesthesia for CEAGeneral Anesthesia for CEA

• Maintain cerebral perfusionMaintain cerebral perfusion

• Minimize myocardial workMinimize myocardial work

• Rapid and smooth emergence to allow Rapid and smooth emergence to allow immediate postoperative neurologic immediate postoperative neurologic assessmentassessment

Advantages of GAAdvantages of GA

• Allows for still, motionless patientAllows for still, motionless patient

• Early control of airway and ventilationEarly control of airway and ventilation

• Ability to protect brain if ischemia Ability to protect brain if ischemia developsdevelops

Blood Pressure ManagementBlood Pressure Management

• Best range is individualized to each Best range is individualized to each patientpatient

• Risk of either myocardial or cerebral Risk of either myocardial or cerebral ischemia is minimized if perfusion ischemia is minimized if perfusion pressures are maintained in the pressures are maintained in the patient’s high normal rangepatient’s high normal range

Choice of Induction AgentChoice of Induction Agent

• All available agents reduce cerebral All available agents reduce cerebral metabolic rate in excess of reduction of metabolic rate in excess of reduction of cerebral blood flowcerebral blood flow

• PentothalPentothal provides best protection against provides best protection against focal ischemiafocal ischemia

• Most rapid awakening with Most rapid awakening with PropofolPropofol• EtomidateEtomidate has most favorable hemodynamic has most favorable hemodynamic

profile but may worsen ischemic neurologic profile but may worsen ischemic neurologic injury (animal data)injury (animal data)

Hemodynamic Response to Hemodynamic Response to Intubation/ HypertensionIntubation/ Hypertension

• Short acting narcoticShort acting narcotic

• Short acting beta-Short acting beta-blockerblocker

• Nitroglycerin or Nitroglycerin or NitroprussideNitroprusside

Maintenance with a Maintenance with a Volatile AgentVolatile Agent

• All presently clinical available agents reduce All presently clinical available agents reduce cerebral metabolic ratecerebral metabolic rate

• IsofluraneIsoflurane has the most pronounced effect has the most pronounced effect with a minimum of myocardial depressionwith a minimum of myocardial depression

• Newer agents allow for more rapid Newer agents allow for more rapid emergence ( emergence ( SevofluraneSevoflurane, , DesfluraneDesflurane))

• Maintain at a lighter plane to allow rapid Maintain at a lighter plane to allow rapid emergence and an easily interpretable EEGemergence and an easily interpretable EEG

Hypotensive Response to Hypotensive Response to InductionInduction

• Hypertensive patients often present in a Hypertensive patients often present in a mildly hypovolemic statemildly hypovolemic state

• Small fluid bolusesSmall fluid boluses

• PhenylephrinePhenylephrine

Maintenance EventsMaintenance Events

• Cervical incision not especially Cervical incision not especially stimulatingstimulating

• Rapid changes in pulse rate and blood Rapid changes in pulse rate and blood pressure/ hemodynamic instability can pressure/ hemodynamic instability can be frequentbe frequent

• Role of short acting agents/ vasoactive Role of short acting agents/ vasoactive drugsdrugs

Blood Pressure ManagementBlood Pressure Management

• Phenylephrine-Phenylephrine- α-agonist with no α-agonist with no direct effect on cerebral vasculature; direct effect on cerebral vasculature; cerebral perfusion increased by cerebral perfusion increased by elevating perfusion pressureelevating perfusion pressure

• Ephedrine-Ephedrine- Mixed α and β activity Mixed α and β activity

Stimulation of Carotid Stimulation of Carotid BaroreceptorBaroreceptor

• Manipulation can Manipulation can result in sustained result in sustained bradycardiabradycardia

• Infiltration with local Infiltration with local agent in carotid agent in carotid sinus areasinus area

• atropineatropine

TachycardiaTachycardia

• Not well tolerated in Not well tolerated in the beta-blocked the beta-blocked patientpatient

• Short acting beta-Short acting beta-blocker – e.g. blocker – e.g. esmololesmolol

Management of VentilationManagement of Ventilation

• Maintain Maintain normocarbianormocarbia

• Hypercapnea may Hypercapnea may cause cerebral steal cause cerebral steal syndromesyndrome

• Hypcapnea may Hypcapnea may decrease cerebral decrease cerebral perfusionperfusion

• LMA vs. ETT?LMA vs. ETT?

Emergence IssuesEmergence Issues

• CoughingCoughing

• Hyperdynamic circulationHyperdynamic circulation

• Stress on suture linesStress on suture lines

• Deep extubation?Deep extubation?

• Airway topicalization?Airway topicalization?

Neurologic Monitoring During Neurologic Monitoring During GAGA

• No monitoring modality is as effective No monitoring modality is as effective as watching an awake patientas watching an awake patient

• Rational for monitoring is to identify Rational for monitoring is to identify which patients need shunting or which patients need shunting or selective blood pressure augmentationselective blood pressure augmentation

Carotid Shunts ProblemsCarotid Shunts Problems

• Carotid emboliCarotid emboli• Intimal dissectionIntimal dissection• Limited surgical Limited surgical

exposureexposure

Commonly Used MonitorsCommonly Used Monitors

• EEGEEG

• Somatosenory-evoked potentials Somatosenory-evoked potentials SSEP’sSSEP’s

• Transcranial DopplerTranscranial Doppler

• Internal carotid artery stump pressureInternal carotid artery stump pressure

EEG MonitoringEEG Monitoring

•Measures electrical activity of cortical neurons

•Cortical ischemia is manifested as ipsilateral cortical slowing, attenuation, or both

•EEG signal is usually diminished when cerebral blow flow < 15 ml/ 100 gm of brain tissue

•Below 12-15 ml/ 100 gm brain tissue there is the beginning of cortical ischemia

Causes of EEG ChangesCauses of EEG Changes

• Ischemia from cross clampingIschemia from cross clamping

• Shunt MalfunctionShunt Malfunction

• HypotensionHypotension

• Contralateral carotid stenosisContralateral carotid stenosis

• Cerebral EmboliCerebral Emboli

Limits of EEG MonitoringLimits of EEG Monitoring

• Inability to detect subcortical injuryInability to detect subcortical injury

• High false positive rateHigh false positive rate

• Diminished sensitivity in patients with Diminished sensitivity in patients with prior strokeprior stroke

• Majority of intraoperative strokes are Majority of intraoperative strokes are embolic in natureembolic in nature

• Most strokes occur postoperativelyMost strokes occur postoperatively

SSEP’SSSEP’S

• Unlike EEG, it can detect deep brain Unlike EEG, it can detect deep brain and brainstem ischemiaand brainstem ischemia

• Ischemia causes a detectable decrease Ischemia causes a detectable decrease in signal amplitude with a concomitant in signal amplitude with a concomitant increase in signal latencyincrease in signal latency

• Data is unclear whether this is actually Data is unclear whether this is actually more sensitive than EEGmore sensitive than EEG

Transcranial DopplerTranscranial Doppler

• Allows continuous noninvasive Allows continuous noninvasive assessment of blood flow velocityassessment of blood flow velocity

• Can detect emboli in ipsilateral middle Can detect emboli in ipsilateral middle cerebral arterycerebral artery

• In presence of a shunt, can determine In presence of a shunt, can determine shunt adequacyshunt adequacy

Carotid Artery Stump PressureCarotid Artery Stump Pressure

• Mean arterial pressure cephalad to Mean arterial pressure cephalad to carotid cross clampcarotid cross clamp

• Needle artery and connect to pressure Needle artery and connect to pressure transducertransducer

• Pressure is generated by back pressure Pressure is generated by back pressure from Circle of Willisfrom Circle of Willis

• Minimal pressures believed to be in the Minimal pressures believed to be in the 25 to 70 mm Hg range25 to 70 mm Hg range

Other Neuro-MonitorsOther Neuro-Monitors

• Jugular bulb oxygen saturationJugular bulb oxygen saturation

• Cerebral blood flow measurements Cerebral blood flow measurements using injection of xenon-133 and using injection of xenon-133 and calculation done with scintilographycalculation done with scintilography

Regional Anesthesia TechniquesRegional Anesthesia Techniques

• Requires the correct combination of Requires the correct combination of surgeon, anesthesiologist and patient to surgeon, anesthesiologist and patient to be successfulbe successful

• Deep and Superficial Cervical Plexus Deep and Superficial Cervical Plexus BlockBlock

• Epidural anesthesiaEpidural anesthesia

• Local infiltrationLocal infiltration

Advantages of Regional Advantages of Regional AnesthesiaAnesthesia

• Awake patient- allowing for repeated Awake patient- allowing for repeated neurologic evaluationsneurologic evaluations

• Can avoid complicated neurologic monitorsCan avoid complicated neurologic monitors• Greater hemodynamic stabilityGreater hemodynamic stability• Improved cross clamp toleranceImproved cross clamp tolerance• Reduced hospital stay and costsReduced hospital stay and costs• Lower (?) incidence of stroke and cardiac Lower (?) incidence of stroke and cardiac

morbiditymorbidity

Disadvantages of Regional Disadvantages of Regional AnesthesiaAnesthesia

• Inability to use pharmacologic cerebral Inability to use pharmacologic cerebral protectionprotection

• Requires a cooperative, non-claustrophobic Requires a cooperative, non-claustrophobic patientpatient

• Possibility of seizuresPossibility of seizures• Poor access to the airway if GA becomes Poor access to the airway if GA becomes

necessarynecessary• Phrenic and superior laryngeal nerve block is Phrenic and superior laryngeal nerve block is

commoncommon

Other ProblemsOther Problems

• Conversion rate to GA reported to be Conversion rate to GA reported to be around 3%around 3%

• Patients who undergo CEA and develop Patients who undergo CEA and develop neurologic changes under Cervical neurologic changes under Cervical Plexus Block are 6 times more likely to Plexus Block are 6 times more likely to suffer a strokesuffer a stroke

Relevant AnatomyRelevant Anatomy

• Cervical Plexus is formed by the 1Cervical Plexus is formed by the 1stst 4 4 cervical nervescervical nerves

• Nerves pass laterally along respective Nerves pass laterally along respective vertebral transverse processesvertebral transverse processes

• At the tips of C-2 to C-4 the nerves At the tips of C-2 to C-4 the nerves divide into ascending and descending divide into ascending and descending branches and form loops before uniting branches and form loops before uniting into deep and superficial branchesinto deep and superficial branches

Anatomy ContinuedAnatomy Continued

• The plexus is situated in front of the The plexus is situated in front of the levator scapulae and scalenus medius and levator scapulae and scalenus medius and covered by the sternocleidomastoid covered by the sternocleidomastoid musclemuscle

• The deep branches are purely motorThe deep branches are purely motor• The superficial branches are sensory and The superficial branches are sensory and

supply the skin and subcutaneous tissues supply the skin and subcutaneous tissues of the neck and posterior aspect of the of the neck and posterior aspect of the headhead

Sensory AnatomySensory Anatomy

• The side of the neck may also derive The side of the neck may also derive sensation from the trigeminal nervesensation from the trigeminal nerve

• The platysma receives some sensory The platysma receives some sensory innervation from cervical branches of innervation from cervical branches of the facial nervethe facial nerve

Cervical PlexusCervical Plexus

Plexus DiagramPlexus Diagram

Technique of Cervical Plexus Technique of Cervical Plexus BlockBlock

• Superficial block requires infiltration Superficial block requires infiltration along posterior border of along posterior border of sternocleidomastoid musclesternocleidomastoid muscle

• Deep plexus requires block of the nerve Deep plexus requires block of the nerve roots are they pass through the roots are they pass through the intervertebral foramina of C-2,C-3,& C-4intervertebral foramina of C-2,C-3,& C-4

Superficial Plexus BlockSuperficial Plexus Block

Deep Plexus BlockDeep Plexus Block

Materials for BlockMaterials for Block

• Regular length #25 spinal needleRegular length #25 spinal needle

• Short (1-1.5 inch) spinal needleShort (1-1.5 inch) spinal needle

• Intermediate acting local anesthetic- 1% Intermediate acting local anesthetic- 1% lidocaine, 0.5% bupivicaine, etc.lidocaine, 0.5% bupivicaine, etc.

• Use 10 to 20 cc of anesthetic for Use 10 to 20 cc of anesthetic for superficial plexussuperficial plexus

• 3 to 5 cc at C-2, C-3, C-43 to 5 cc at C-2, C-3, C-4

Superficial vs. Deep Plexus Superficial vs. Deep Plexus BlockBlock

• 3 different randomized trials (205 patients) 3 different randomized trials (205 patients) could not demonstrate clear benefit if deep could not demonstrate clear benefit if deep block was done with superficial block or block was done with superficial block or notnot

• Same VAS scoresSame VAS scores

• Same need for additional supplementationSame need for additional supplementation

• Some authors question if there is a real Some authors question if there is a real anatomic basis for any differenceanatomic basis for any difference

Supplemental BlockSupplemental Block

• Manibular branch of Manibular branch of trigeminal nervetrigeminal nerve

Surgical ApproachSurgical Approach

• Ventrojugular approach is standard Ventrojugular approach is standard surgical techniquesurgical technique

• This approach improves patient toleranceThis approach improves patient tolerance

• This technique is associated with a higher This technique is associated with a higher transient incidence ipsilateral vocal cord transient incidence ipsilateral vocal cord motility impairment because of a need for motility impairment because of a need for greater vagal nerve mobilizationgreater vagal nerve mobilization

Cervical Plexus ComplicationsCervical Plexus Complications

• Deep plexus blockDeep plexus block::• Intravascular injectionIntravascular injection• Subarachnoid injection with brain stem Subarachnoid injection with brain stem

anesthesiaanesthesia• Phrenic nerve blockPhrenic nerve block• Recurrent laryngeal nerve blockRecurrent laryngeal nerve block• Vagus nerve blockVagus nerve block• Horner’s syndromeHorner’s syndrome

Cervical Plexus ComplicationsCervical Plexus Complications

• Superficial plexus blockSuperficial plexus block• Intravascular injectionIntravascular injection• Recurrent laryngeal nerve block if injection Recurrent laryngeal nerve block if injection

is made deeper than the inferior border of is made deeper than the inferior border of the SCM musclethe SCM muscle

• Partial brachial plexus block has been Partial brachial plexus block has been reportedreported

Incidence of ProblemsIncidence of Problems

• Pandit et al did not find a single incidence of Pandit et al did not find a single incidence of serious complications related to superficial serious complications related to superficial block in a review of 2500 cases collected from block in a review of 2500 cases collected from several publicationsseveral publications

• In this review serious complications defined as In this review serious complications defined as life threatening occurred in only 0.25% of life threatening occurred in only 0.25% of patients (inadvertent subarachnoid injection, patients (inadvertent subarachnoid injection, respiratory distress from phrenic or laryngeal respiratory distress from phrenic or laryngeal nerve block)nerve block)

• Br J Anaesth 2007,99:159-169Br J Anaesth 2007,99:159-169

Additional ProblemsAdditional Problems

• Deep blocks done alone are associated Deep blocks done alone are associated with a higher conversion rate to GA with a higher conversion rate to GA (2.1% vs. 0.4%)(2.1% vs. 0.4%)

• When deep and superficial blocks are When deep and superficial blocks are done together the incidence of done together the incidence of ipsilateral hemidiaphragmatic paralysis ipsilateral hemidiaphragmatic paralysis is 55 to 61%is 55 to 61%

Choice of Local AnestheticChoice of Local Anesthetic

• Bupivicaine 0.5% provides the longest Bupivicaine 0.5% provides the longest time to request for first analgesiatime to request for first analgesia

• Ropivicaine is probably the least Ropivicaine is probably the least cardiotoxiccardiotoxic

• Use the least possible amount of total Use the least possible amount of total anesthetic in any case.anesthetic in any case.

Outcomes: Local vs. GAOutcomes: Local vs. GA

• One series of 548 casesOne series of 548 cases• Local was 10 cc lidocaine for skin, 10 cc Local was 10 cc lidocaine for skin, 10 cc

for platysmafor platysma• GA was thiopental with isoflurane, nitrous-GA was thiopental with isoflurane, nitrous-

oxide/oxygen, fentanyl maintenance oxide/oxygen, fentanyl maintenance • No differences in postoperative stroke or No differences in postoperative stroke or

death ratedeath rate

• Watts et al Am. J Surg 2004; 188:741-747Watts et al Am. J Surg 2004; 188:741-747

Outcomes: Patient SatisfactionOutcomes: Patient SatisfactionLocal vs. GALocal vs. GA

• Prospective randomized study of 176 Prospective randomized study of 176 patients comparing CEA under local or GApatients comparing CEA under local or GA

• Only the recovery was significantly better Only the recovery was significantly better with the local groupwith the local group

• No differences in anxiety or satisfactionNo differences in anxiety or satisfaction

• McCarthy et al. Eur J Vasc Endovasc Surg 2001; McCarthy et al. Eur J Vasc Endovasc Surg 2001; 27:654-65927:654-659

Anesthetic Technique and Anesthetic Technique and Surgical Stress ResponseSurgical Stress Response

• Prospective trial of 109 patientsProspective trial of 109 patients• Cortisol, ACTH, prolactin, and C-reactive Cortisol, ACTH, prolactin, and C-reactive

protein were measured before and after carotid protein were measured before and after carotid cross clamping and then daily for 3 days aftercross clamping and then daily for 3 days after

• Cortisol and ACTH levels were higher in the Cortisol and ACTH levels were higher in the regional group but this effect was abolished if a regional group but this effect was abolished if a shunt was usedshunt was used

• Marrocco-Trischitta et al. J Vasc Surg 2004; 39:1295-1304Marrocco-Trischitta et al. J Vasc Surg 2004; 39:1295-1304

Conclusions: Regional vs. GAConclusions: Regional vs. GA

• No clear data to suggest improved No clear data to suggest improved outcome in perioperative neurologic outcome in perioperative neurologic problemsproblems

• GA can be combined with plexus block GA can be combined with plexus block and can result in greater hemodynamic and can result in greater hemodynamic stability and shorter operating timesstability and shorter operating times

• Reg Anesth Pain Med 2008;33:340-345Reg Anesth Pain Med 2008;33:340-345

Complications:Complications:PACU Issues/ Postoperative CarePACU Issues/ Postoperative Care• HypertensionHypertension

• HypotensionHypotension

• Myocardial ischemia or infarctMyocardial ischemia or infarct

• Cranial nerve injuryCranial nerve injury

• Recurrent Laryngeal Nerve injuryRecurrent Laryngeal Nerve injury

• StrokeStroke

• BleedingBleeding

Postoperative HypertensionPostoperative Hypertension

• Can be secondary to local infiltration Can be secondary to local infiltration around the carotid sinus or its nerve- around the carotid sinus or its nerve- can be profound in 20% of patientscan be profound in 20% of patients

• Patients with poorly controlled BP are at Patients with poorly controlled BP are at riskrisk

• Severe hypertension is associated with Severe hypertension is associated with increased mortality, increased cardiac increased mortality, increased cardiac and neurologic morbidityand neurologic morbidity

Management Options for Management Options for Postoperative HypertensionPostoperative Hypertension

• Short acting agents such as esmolol Short acting agents such as esmolol and nitroglycerin are considered 1and nitroglycerin are considered 1stst line line agentsagents

• IV titration of labetolol or hydralazineIV titration of labetolol or hydralazine

• Nitroprusside infusionNitroprusside infusion

• Nicardipine infusionNicardipine infusion

Postoperative Hypoperfusion Postoperative Hypoperfusion SyndromeSyndrome

• Somewhat uncommonSomewhat uncommon• Results from impaired cerebral Results from impaired cerebral

autoregulation in the surgically reperfused autoregulation in the surgically reperfused hemispherehemisphere

• Manifested as headache, seizure, Manifested as headache, seizure, neurologic deficit, cerebral edema, or neurologic deficit, cerebral edema, or hemorrhage. hemorrhage.

• CT scan- intracerebral hemorrhage, white CT scan- intracerebral hemorrhage, white matter edemamatter edema

HypotensionHypotension

• May be related to carotid baroreceptor May be related to carotid baroreceptor hypersensitivity after plaque removalhypersensitivity after plaque removal

• Can result in myocardial or cerebral Can result in myocardial or cerebral ischemiaischemia

• Consider judicious amounts of fluid Consider judicious amounts of fluid replacement and sympathomimetic replacement and sympathomimetic agents for supportagents for support

Postoperative Respiratory Postoperative Respiratory InsufficiencyInsufficiency

• Massive hematoma formation (active Massive hematoma formation (active bleeding, coagulopathy)bleeding, coagulopathy)

• Bilateral recurrent laryngeal nerve injuryBilateral recurrent laryngeal nerve injury

• Soft tissue swelling, supraglottic Soft tissue swelling, supraglottic mucosal edemamucosal edema

Carotid Body DenervationCarotid Body Denervation

• Secondary to surgical manipulationSecondary to surgical manipulation

• Results in impaired response to hypoxiaResults in impaired response to hypoxia

• Can be clinically significant in presence Can be clinically significant in presence of agents which depress respirationof agents which depress respiration

• May be exaggerated with moderate to May be exaggerated with moderate to severe COPDsevere COPD

• Consider using non-narcotic analgesiaConsider using non-narcotic analgesia

Cranial Nerve DysfunctionCranial Nerve Dysfunction

• Generally secondary to surgical traction Generally secondary to surgical traction not transectionnot transection

• Generally transient- resolution within 6 Generally transient- resolution within 6 monthsmonths

• Dysphagia/ Hoarseness- recurrent Dysphagia/ Hoarseness- recurrent laryngeal nerve injurylaryngeal nerve injury

• Tongue deviation – hypoglossal nerve Tongue deviation – hypoglossal nerve injuryinjury

Myocardial InfarctionMyocardial Infarction

• A major cause of morbidityA major cause of morbidity

• Symptoms and EKG changes should be Symptoms and EKG changes should be investigated promptlyinvestigated promptly

• Hemodynamic instabilityHemodynamic instability

• ArrhythmiaArrhythmia

• Maximize the balance between Maximize the balance between myocardial oxygen supply and demandmyocardial oxygen supply and demand

Parting ThoughtsParting Thoughts

• CEA requires a multi-disciplinary team CEA requires a multi-disciplinary team approach from the pre-op period through approach from the pre-op period through convalescenceconvalescence

• CEA is a prophylactic procedure requiring CEA is a prophylactic procedure requiring careful patient selectioncareful patient selection

• Close intraoperative communicationClose intraoperative communication• There is no data to strongly support any There is no data to strongly support any

specific anesthetic approach as long as specific anesthetic approach as long as CBF is maintained and hemodynamic CBF is maintained and hemodynamic stress is limitedstress is limited