Valvular diseases Flashcards
Big take away for anesthesia management in mitral stenosis
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
Preop eval
Syncope, fainting, compensation?
Major end organ disease?
Cardiac hypertrophy, increased SNS output for compensation?
How bad is the CV disease?
One of the single best questions for many CV assesments
Exercise tolerance
Common symptoms of CHF with valve disease
Dyspnea, orthopnea, fatigue
Signs of increased SNS outflow as compensation
Common dysrhythmias
What can angina point to in valvular disease
Anxiety, diaphoresis, resting tachycardia
A-fib
Possible cardiac hypertrophy and inability to supply it sufficient O2
Common drug therapies in valvular disease
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
In valvular disease what would one expect on an ABG
Low PaO2, V-Q mismatch
Mitral stenosis patho
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
Mitral stenosis symptoms
DOE when CO is increased
Severe disease can lead to congestive heart failure
What are two goals for management of mitral stenosis during induction
AVOID tachycardia (no ketamine)
AVOID abrupt decreases in SVR (careful with propofol)
Sounds like a job for etomidate
Maintenance in mitral stenosis
Avoid marked and sustained changes in HR, SVR, PVR, and contractility. Balanced anesthesia approach may be necessary.
May require invasive monitoring
Mitral regurg patho
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.
What does regurgitant flow show up as on a PA waveform
V wave
Size of the wave correlates with magnitude of the regurg flow
Big takeaway for anesthesia management in mitral regurg
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
Induction in mitral regurg
Try to maintain pre-op vitals. High SVR and low HR in particular should be avoided.
Etomidate also a good choice here.
What parameter guides maintenance of anesthesia in mitral regurg
Left ventricular function
Mitral regurg maintenance:
Non-severe LV dysfunction
Severe LV dysfunction
N2O plus VA such as isoflurane
High dose opioid technique
Aortic stenosis patho
Calcification and stenosis of congenitally abnormal bicuspid valve
When caused by rheumatic fever it is almost always associated with mitral valve stenosis
Hemodynamically significant aortic stenosis is associated with what two parameters
Transvalvular pressure gradient >50mmHg
Aortic valve orifice < 1cm sq (normal is 2.5-3.5)
Big takeaway for anesthesia management in aortic stenosis
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
Is GA or regional a better choice in aortic stenosis
GA- regional can lead to large decreases in SVR that are difficult to treat
Aortic regurg patho
Acute- infective endocarditis, trauma, aortic dissection
Chronic- Prior rheumatic fever, long standing HTN
What is the basic hemodynamic problem in aortic regurg
Decreased left vent. forward stroke volume from portion that leaks back into the LV
Big takeaway for management of anesthesia in aortic regurg
Maintain forward left vent. stroke volume!
Goals: Avoid decreased HR, sudden increases in SVR, minimize drug-induced myocardial depression
Induction in aortic regurg
Just use etomidate (no myocardial depressants, no increases in SVR)
Maintenance of anesthesia in aortic regurg
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
Tricuspid regurg
Usually functional, well tolerated
Reflects a dilated RV from pulm HTN, leads to RV overload
