Cardiac Surgery Flashcards
What calculator is used to risk stratify for cardiac surgery patients in the US?
Society of Thoracic Surgeons Risk Calculator
What does a P2Y12 assay measure?
Responsiveness to Plavix
What is the gold standard for diagnosing CAD?
Left heart cath
How is valvular function evaluated?
TTE
What kind of study tells you if the heart can be re-perfused post MI?
A PET viability study
What percent of carotid stenosis would necessitate a consult pre-op to determine if pt is a candidate for carotid endarterectomy?
80% or greater
What is a sternotomy?
An incision in the midline of the chest
Mini thoracotomy is done mostly for what type of surgeries?
Valve surgeries
What is cardioplegia?
Temporary intentional arrest of the heart
How is cardioplegia done?
With a high K+ solution
Who manages the cardiopulmonary bypass machine?
The perfusionist
What are the two main indications for a CABG?
Significant left main coronary artery stenosis or presence of 3 vessel disease
What percent stenosis of the left main coronary artery is considered “significant”?
50% or greater
What artery is most often used to bypass the left anterior descending coronary artery?
Internal mammary artery
What is the advantage of doing a bypass with the internal mammary artery over the saphenous vein?
Internal mammary artery bypass lasts longer
What is tricuspid valve disease usually a result of?
Rheumatic heart disease or lung disease
Which valve is rarely operated on?
The tricuspid valve
When is surgery indicated for mitral valve stenosis?
For severely symptomatic pts - NYHA Class III or IV
Acute mitral regurgitation is usually caused by what?
An MI causing papillary muscle rupture, endocarditis
Aortic stenosis is usually a result of what?
Degenerative related issues
When should pts with aortic stenosis undergo surgery?
When they are symptomatic
When would you perform an aortic valve replacement in an asymptomatic pt?
If they have LV dysfunction with EF<50%
Should all symptomatic aortic regurgitation pts be operated on?
Yes
Severe aortic stenosis is when the valve opening is smaller than what?
0.8cm2
What does an annuloplasty ring help with?
Valvular regurgitation
What is a commissurotomy done for?
Stenotic valves
What is a commissurotomy?
Surgeon opens up the valve to decrease stenosis
Which lasts longer, mechanical or bioprosthetic valves?
Mechanical
Which type of valve requires lifelong anticoagulation with warfarin?
Mechanical
How long do bioprosthetic valves need antiplatelet therapy after placement?
Three months
What must be done if a prosthetic valve becomes infected?
Surgical replacement
When is a transcatheter aortic valve implantation done?
When pt is too sick for open heart surgery
What is the goal time to extubate after cardiac surgery?
Within 4-6 hours after leaving the OR
What type of ventilation should cardiac pts be on before extubation?
Pressure support
PEEP should be what before extubation?
5-8
FiO2 should be what before extubation?
Less than or equal to 0.4
How is glycemic control managed in diabetic cardiac surgery pts?
They will all be placed on an insulin drip after surgery
What is the goal blood sugar for cardiac surgery pts?
140-180
What happens to volume status after cardiac surgery?
Most pts end surgery about 5-10% above their pre-op weight (volume overloaded)
Why do cardiac surgery pts need a lot of volume after surgery?
Kidneys excrete a large amount of urine, so volume is needed to maintain hemodynamics
Hematocrit should be what in the immediate post-op period?
27-30
What should platelets be for surgical pts?
Above 50k
How many units of plasma should you give if pt has high INR and is actively bleeding?
2-4 units
What is protamine used to reverse?
Heparin
Heparin elevates what lab value?
PPT
What is fibrinogen given for?
Low cryoprecipitate
How much cryo do you give?
1 unit per 10kg of body weight
In what order do you address hemodynamics?
Preload, afterload, contractility
What is vasoplegia?
Very low SVR
What medication use increases risk of vasoplegia after surgery?
Ace inhibitors
When should ACEI be stopped prior to cardiac surgery?
One week prior
What is methylene blue used to treat?
Vasoplegia
What is the most common complication after cardiac surgery?
A fib
How do we treat unstable afib?
Cardiovert
Can you give cardiac surgery pts calcium channel blockers for afib rate control?
No
How should cardiac surgery pts be treated for afib after surgery?
Beta blockers
Is rate control or rhythm control more important for cardiac surgery pts with afib?
Rhythm control
When should anticoagulation be started on a cardiac surgery pt in afib?
After 36-48 hours without conversion to NSR
What is an MI defined as?
A new Q wave on an EKG
Is there any benefit to starting CCRT after cardiac surgery for kidney failure?
No
What are the three most common causes of cardiac arrest after surgery?
Vfib, vtach, cardiac tamponade
Why should epi not be used in cardiac arrest after surgery?
May damage graft
What do you do if pt is in VT/VF?
Defib up to 3x, do not start chest compressions for one minute
What do you do if pt is in asystole or bradycardic?
Pace
What do you do is pt is in PEA?
ACLS
What do you do if you’ve been attempting to resuscitate a post surgery arrest pt for 5+ minutes without success?
Re-sternotomy (usually at bedside) with cardiac massage
