Anesthesia for Vascular Surgery - Quiz 4 Flashcards
For pts w/ PVD & PAD, how must the MAP change in order to perfuse vital organs?
MAP must Increase
Why are ART lines recommended for pts w/ PVD & PAD?
Hypotension, even for a little, can cause Ischemia
What are the Major Risk Factors for Abdominal Aortic Aneurysms?
Smoking
Old Age
Men > Women
White > Black
How are AAAs diagnosed?
Computed Tomography Angiography (CTA)
&
Pulsatile Abdominal Mass
When is Surgical Intervention recommended for AAAs?
> 5.5 cm
4.5 w/ >0.5 cm growth in 6 months
Ruptured AAA
Symptomatic AAA
How much do AAAs expand each year?
4mm / year
In regards to AAAs, the Wall Tension is _____ proportional to Vessel Radius & Pressure, and ______ proportional to Wall Thickness.
In regards to AAAs, the Wall Tension is Directly proportional to Vessel Radius & Pressure, and Indirectly proportional to Wall Thickness.
Which Artery is this?
Right Coronary Artery
What are Contraindications to Elective AAA Repair?
Intractable Angina
Recent MI
Severe Pulm. Dysfunction
Chronic Renal Insufficiency
What is the most common and preferred site of Abdominal Aortic Aneurysms?
Infrarenal
What meds should be given to patients prior to AAA repair to optimize Myocardial Oxygen Supply & Demand?
B-Blockers
Statins
Fluid Load
Which EKG leads should be used for AAA repairs?
Lead II - Arrythmias
&
Lead V5 - ST Changes
How is Blood Pressure affected by Aortic Cross Clamping?
↑BP above Clamp
↓BP below Clamp
↑Afterload
↑SVR
↑MAP
What are pts w/ Poor LV function at risk for with Cross Clamping?
CHF
↑Afterload = ↑LV Wall Tension & O2 Demand
Which Artery is this?
Right (Acute) Marginal Artery
What is the main factor that causes Cardiac Instability & Depression during Cross Clamping?
Release of Archidonic Acid
Aside from Arachidonic Acid, what other substances are released during Cross Clamping?
Cytokines
Prostaglandins
Nitric Oxide
What happens to the Heart w/ an Increase in Thomboxane A2 production?
↓Contractility
&
↓Cardiac Ouptut
What are symptoms of Mesenteric Traction Syndrome from Cross Clamping?
Hypotension
Tachycardia
↑Cardiac Output
Facial Flushing
Which sites of cross clamp have a higher risk for Acute Kidney Injury?
Suprenal & Juxtarenal - 80% renal blood flow reduction
(40% w/ Infrarenal)
What can happen if a Suprarenal Cross Clamp is in place over 30 minutes?
Post-Op Renal Failure
What meds should be avoided to prevent AKI from Cross Clamping?
NSAIDs
Gentamicin
Neomycin
Which arteries supply 20% of Spinal Cord blood flow to the Dorsal/Sensory portion?
Posterior Artery x 2
&
Posterolateral Arteries x 2
Which artery is this?
Left Coronary Artery
Which artery supplies 80% of the Spinal Cord blood flow to the Motor Portion?
Anterior Spinal Artery
Damage to which artery causes Spinal Cord Ischemia?
Greater Radicular Artery / Adamkiewicz - tranverse blood flow to spinal cord
What are ways to minimize risk of Spinal Cord Ischemia?
CSF Drainage
Mild Hypothermia
Keep SBP > 120 mmHg thru Post Op Day 2
What are the Hemodynamic Changes associated w/ Cross Clamp Release?
↓Contractility & Cardiac Output
↓CVP & Venous Return
↓SVR, Preload & Afterload
What causes the Transient Vasodilation w/ Cross Clamp Release?
Release of built up Anaerobic Metabolites
Release of Adenine
Tissue Hypoxia
When used, what are the advantages of an Epidural for Open AAA Repair?
↓Preload & Afterload
Preserves Cardiac Oxygen
↓Stress Response
↓Pulmonary Problems
Post-Op Pain Control