anesthesie voor vaatheelkunde - website - uz leuven · 21-10-2016 4 carotid endarterectomie •...

21-10-2016

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Dr. Danny HoogmaAnesthesiology

Anesthesia for vascular surgery

Overview

• Introduction

• Preoperative optimalization

• Monitoring

• Intra-operative management– Carotid endarterectomy– Aortic surgery

– Peripheral vascular surgery

• Conclusion

Leerdoelen:

• Atherosclerose is een systeem ziekte

• Carotis end-arterectomie– monitoring– complicaties

• Aorta chirurgie en cross-clamp

• Perifeer vasculaire chirurgie is high risk

Introduction

• Atherosclerosis– Systemic disease

• Endothelial dysfunction• End-organ dysfunction possible

– Lipids accumulation– Inflammatory proces

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Atherosclerosis

• Risk factors– Arterial hypertension– Diabetes– Smoking

– Hypercholesterolemia– Male– Genetic– Obesity

Preoperative identification

• Revised cardiac risk index:– Risk of surgery– Patient factors

• Pharmacological treatment

• Les: Anesthesia for the cardiovascular compromised patient

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Clinical evaluation

• Cardiac, neurological, pulmonary, renal…

• Diabetes

• Smoking

• Bloodpressure– Bilateral measurement

Preoperative investigations

• Functional capacity

• ECG

• Cardiac stress testing

• …

Monitoring

• Hemodynamic:– Bloodpressure

– ECG, lead II en V– Centrale acces– TEE– Fore-sight / NIRS / Neurowave

• Neurological:– SSEP/MEP/EEG– Clinically

Perioperative management

• Carotid endarterectomy

• Aortic surgery

• Peripheral vascular surgery

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Carotid endarterectomie

• Symptoms: – Amaurosis fugax -> CVA

• Etiology– Progressieve occlusie door plaque

• Circulus van Willis

– Emboli

• Intervention?– Highly beneficial: symptomatisch / stenose 70-99%

– Moderately beneficial: 50-69% stenose (occulairplethysmografie)

Type of anaesthesia

• Regional?– Cervical blok C1-C4– Neuromonitoring +++

• General anesthesie?– Control (pulmonary and hemodynamic)

– Potential protective effect of anaesthetics

• Goal = maintain bloodpressure = perfussion

Cerebral circulation

• Aerobic metabolism

• Major part of cardiac output– CBF = 50 ml/100g/min

• Prone for irreversible ischaemia– Threshold = CBF < 20 ml/100g/min

• Blood brain barrier

• Rigid box

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CBF and brain tissue

Cerebral bloodflow

• Autonomic nervous system– Perfusion pressure = MAP-ICP

Cerebral bloodflow

• Metabolic regulation– Nerve activity (adenosin)– PaCO2

– pH CSV

– PaO2

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Monitoring• Carotid stump pressure?

– CBF not known– Low specificity (> shunts)

• Transcranial doppler?– A. Cerebri media

• Continuous, non invasive and detection of emboli possible• Only 1 vessel…, what about signal detection

• NIRS?– Evaluation delivery vs consumption– Only frontal cortex

• EEG en SSEP?– EEG: cerebral activity, SSEP: evalution of nerve fiber up to the cortex– Neuron evaluation: hibernation if CBF <16-18 ml/100g/min, cell necrosis if <10-12

ml/100g/min– Multifactorial interference


• Perioperative events– Emboli 60-95%

• Manipulation carotis = surgeon

– Hypoperfusion = anaesthetist• Autoregulatory dysfunction (belang perfusie

druk)• Normal-high bloodpressure

– ‘light anesthesia’ + vasopressors

– Glycemia < 150 mg/dl


• Perioperative events– Rhythm disturbances

• Glomus/vagus manipulation � atropin/lidocain

– Ventilation• Hypocapnia

– Decreased CBF

• Hypercapnia– Vasodilation in non-ischemic areas (steal

phenomenon)


• Shunt needed?– Hypoperfusion (cave emboli)

• Lengthens procedure time

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– Patient selection!• Preoperative

– occlusion/stenosis other vessels? – Recent ischemia = high risk for new perioperative event

• Clinical neurological evaluation • Hemodynamic evaluation

– Carotid stump pressure (insufficient specificity)– Transcranial doppler– NIRS

• Neurologic evaluation– EEG, SSEP, Neurowave– Effect anesthestics

CAS = carotid artery stenting


• Postoperative– Neurologic evaluation

• Epileptic insult, nerve injury (surgical), TIA/CVA

– Hemodynamic instability• Baroreceptor dysfunction

– Hyperperfusion syndrome– Bleeding

• Cave difficult airway

– Cardiac morbidity (myocardial infarction)

Aortic surgery

• Dissection

• Rupture

• Aneurysm

• Occlusion

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Aortic surgery

• Cross-clampling– Major cardiovascular, humoral en metabolic

impact

• Artery of Adamkiewicz– Drainage of liquor?

• Deep hypothermic cooling with circulation stop or usage of the octopussystem

Impact of cross-clamping

Hemodynamic

Myocardial

Metabolic

Renal

Pulmonary

Spinal

Zammert M, Gelman S. The pathophysiology of aortic cross-clamping. Best Practice & Research Clinical Anaesthesiology. 2016 Sep;30(3):257–69.

Redistribution of blood volume

Geen examen-leerstof

Gelman S, Anesthesiology, 1995

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Systemic hemodynamic response



Spinal cord blood flow



Pathophysiology cross-clamp


Peroperative management

• Afterload– Supra-coeliacus clamping (nitrates)

• Preload ↓(nitrates)

• Sympatic block (epidural)

• Shunting– Flow distal to clamp

– Individual organ perfusion

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Monitoring during TAA

• Periferal IV line/invasive ABP/CVC

• ABG/ACT

• Spinal catheter

• Bladder catheter

• Temperature

• TEE/MEP/SSEP/…

Removal of aortic cross-clamp

• Anticipation– Optimalization of intravascular volume– Vasopressors– Progressive declamping

– Pharmacological intervention (ie: bicarbonate, potassium,…)

Unclamping



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Peripheral vascular surgery

• Inflow vs outflow procedure

• Ischemia– 5P: pain, pallor, pulseless, paresthesia,

paralyse

• Claudicatio � cave mobidity and mortality equals abdominal aortic aneurysm repair

Type of anesthesia

• Often general anesthesia

• Regional anesthesia if indicated– Neuraxial LRA often impossible– Peripheral LRA certainly possible

• Risk of perioperative myocardialinfarction no different

Endovascular procedure

• Thoracic and abdominal– EVAR since the ‘80

• Advantage of less surgical inducedstress reponse with a decreasedhemodynamic effects

• Decreased operative mortability andmorbidity but similar long-term outcome

Conclusion

• Hemodynamic stability– Know your pharmacology, the product isn’t

‘dangerous'!• Hypnotics, NMBA, opioid, fluids…

– Decreased tolerance to disturbances

anesthesie voor vaatheelkunde - website - uz leuven · 21-10-2016 4 carotid endarterectomie •...

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