Valvular diseases

Question 1

Big take away for anesthesia management in mitral stenosis

Answer 1

Goals: slow, tight, full

Avoid tachy/SVT

Avoid large increases in fluid volume- use colloid/blood over crystalloid. Careful with head-down positions.

Avoid drug-induced decreases in SVR (High MAC, large propofol doses)

Avoid hypoxemia which can make pulm HTN worse and lead to right ventricular failure

Question 2

Preop eval

Answer 2

Syncope, fainting, compensation?

Major end organ disease?

Cardiac hypertrophy, increased SNS output for compensation?

How bad is the CV disease?

Question 3

One of the single best questions for many CV assesments

Answer 3

Exercise tolerance

Question 4

Common symptoms of CHF with valve disease

Answer 4

Dyspnea, orthopnea, fatigue

Question 5

Signs of increased SNS outflow as compensation

Common dysrhythmias

What can angina point to in valvular disease

Answer 5

Anxiety, diaphoresis, resting tachycardia

A-fib

Possible cardiac hypertrophy and inability to supply it sufficient O2

Question 6

Common drug therapies in valvular disease

Answer 6

Digoxin often given to increase contractility and slow V-rate in a-fib.

Diuretics for removing excess fluid volume. Watch K+ and increased risk for dig toxicity

Prophylactic antibiotics to protect against infective endocarditis

Question 7

In valvular disease what would one expect on an ABG

Answer 7

Low PaO2, V-Q mismatch

Question 8

Mitral stenosis patho

Answer 8

Fusion on leaflets, typically after rheumatic fever. At <1cm sq. a mean left atrial pressure of 25mmHg is needed to maintain CO.

Left atrial enlargement predisposes to a-fib, blood stasis

Question 9

Mitral stenosis symptoms

Answer 9

DOE when CO is increased

Severe disease can lead to congestive heart failure

Question 10

What are two goals for management of mitral stenosis during induction

Answer 10

AVOID tachycardia (no ketamine)

AVOID abrupt decreases in SVR (careful with propofol)

Sounds like a job for etomidate

Question 11

Maintenance in mitral stenosis

Answer 11

Avoid marked and sustained changes in HR, SVR, PVR, and contractility. Balanced anesthesia approach may be necessary.

May require invasive monitoring

Question 12

Mitral regurg patho

Answer 12

Also typically associated with rheumatic fever and almost always associated with mitral stenosis. Ineffective valve allows backflow from the ventricle into the atrium. This leads to left atrial overload.

Question 13

What does regurgitant flow show up as on a PA waveform

Answer 13

V wave

Size of the wave correlates with magnitude of the regurg flow

Question 14

Big takeaway for anesthesia management in mitral regurg

Answer 14

Goals: fast, full, forward

Avoid decreasing CO, aim for normal high

Avoid decreases in HR

Avoid sudden increases in SVR

Monitor size of V wave for changes

Minimize drug-induced myocardial depression

Question 15

Induction in mitral regurg

Answer 15

Try to maintain pre-op vitals. High SVR and low HR in particular should be avoided.

Etomidate also a good choice here.

Question 16

What parameter guides maintenance of anesthesia in mitral regurg

Answer 16

Left ventricular function

Question 17

Mitral regurg maintenance:

Non-severe LV dysfunction

Severe LV dysfunction

Answer 17

N2O plus VA such as isoflurane

High dose opioid technique

Question 18

Aortic stenosis patho

Answer 18

Calcification and stenosis of congenitally abnormal bicuspid valve

When caused by rheumatic fever it is almost always associated with mitral valve stenosis

Question 19

Hemodynamically significant aortic stenosis is associated with what two parameters

Answer 19

Transvalvular pressure gradient >50mmHg

Aortic valve orifice < 1cm sq (normal is 2.5-3.5)

Question 20

Big takeaway for anesthesia management in aortic stenosis

Answer 20

Don’t decrease CO!

Goals: Maintain NSR (CO reliant on atrial kick), avoid bradycardia, avoid sudden changes in SVR, ensure adequate fluid to maintain venous return and LV filling

A-line probably a good idea

Question 21

Is GA or regional a better choice in aortic stenosis

Answer 21

GA- regional can lead to large decreases in SVR that are difficult to treat

Question 22

Aortic regurg patho

Answer 22

Acute- infective endocarditis, trauma, aortic dissection

Chronic- Prior rheumatic fever, long standing HTN

Question 23

What is the basic hemodynamic problem in aortic regurg

Answer 23

Decreased left vent. forward stroke volume from portion that leaks back into the LV

Question 24

Big takeaway for management of anesthesia in aortic regurg

Answer 24

Maintain forward left vent. stroke volume!

Goals: Avoid decreased HR, sudden increases in SVR, minimize drug-induced myocardial depression

Question 25

Induction in aortic regurg

Answer 25

Just use etomidate (no myocardial depressants, no increases in SVR)

Question 26

Maintenance of anesthesia in aortic regurg

Answer 26

Same as mitral regurg- N2O and isoflurane without severe LV dysfunction, high opioid technique with severe LV dysfunction

Use colloid or blood

Treat bradycardia promptly

Question 27

Tricuspid regurg

Answer 27

Usually functional, well tolerated

Reflects a dilated RV from pulm HTN, leads to RV overload