CV1 - the cardiovascular surgical patient Flashcards
High risk surgeries (>5%)
Aortic surgery
Major vascular surgery
Peripheral vascular surgery
Long surgical procedures with significant volume/blood loss
A-M-P-L
Intermediate Risk (1-5%)
Carotid endarterectomy
Peripheral artery angioplasty
Endovascular aneurysm repair
Head and neck surgery
Major neurologic/orthopedic
Intrathoracic
Intraperitoneal
Major urologic
Transplant
Low Risk (<1%)
Breast
Dental
Endoscopic
Superficial
Endocrine
Cataract
Gynecologic
Reconstructive
Minor orthopedic
Minor urologic
What is associated with the highest risk for perioperative MI?
Unstable angina
Revised Cardiac Risk Index
Another tool for predictor of CV morbidity and mortality
High Risk Surgery (aortic, major vascular)
Hx of ischemic heart disease (previous MI, previous positive stress test, use of nitroglycerine, unstable angina, previous PCI or CABG)
Hx CHF
HX cerebrovascular disease
Hx diabetes
Serum creatinine >2mg/dL
ACC/AHA recommend waiting at least ____ days after MI before patient undergoes elective surgery
60
Answer on test could be 1-2 months
If perioperative reinfarction does occur, mortality is approximately ____ %
50%
MI Risk in Patients with Previous MI
General Population = 0.3%
MI if > 6 months = 6%
MI 3-6 months = 15%
MI if < 3 months = 30%
What is a MET defined as?
MET is defined as the amount of oxygen consumed while sitting at rest and is defined as 3.5 ml oxygen/kg/min
Kg x 3.5 ml/consumption/minute
What is perhaps the best question to determine how someone will do under anesthesia?
Can you walk up a flight of stairs?
What are the two questions we ask regarding METS?
- Are you able to walk four blocks without stopping regardless of limiting symptoms?
- Are you able to climb two flights of stairs without stopping regardless of limiting symptoms?
Inability to perform this leads to an 82% increase in risk for cardiopulmonary complications postoperatively
Examples of 1 MET
1 MET – poor functional capacity
Self-care
Eating, dressing, using the toilet
Walking indoors and around the house
Walking one to two blocks on level ground at 2-3 mph
Examples of 4 METS
4 METs –good functional capacity
Light housework
Climbing a flight of stairs without stopping, or walking up a hill longer than 1 to 2 blocks
Walking on level ground at 4 mph
Running a short distance
Golf, dancing, throwing a baseball
Examples of 10 METS
Greater than 10 METs- excellent functional capacity
Strenuous sports
Different classes of CV disability
I - no limitations
II - slight functional limitations
III - comfortable at rest, but minimal activity causes fatigue
IV - symptoms present at rest
What is the predominant CV risk factor for pts undergoing noncardiac surgery?
Active LV failure
Severe aortic stenosis = valvular disorder that poses greatest patient risk for noncardiac surgery
What are the two classes of LV failure?
Preserved EF (>50%)
Reduced EF (<50%)
Heart failure is defined as any of the following:
Hx of CHF, pulmonary edema, paroxysmal dyspnea, BL rales, S3 gallop, CXR showing pulmonary vascular redistribution
When is aortic stenosis especially bad?
Especially when cross sectional area of valve is less than 1 cm2
Associated with a fourteenfold greater incidence of periop sudden death
True/False: In the absence of cardiac disease, benign ventricular arrhythmias do not carry increased surgical risk
True
Pacemakers should be interrogated within _______ of elective surgery, and ICD’s within _____ months
12 months, 6 months
Interoperative key point for pacemakers
Electromagnetic interference risk is LOW if the device is less than 10 years old and bipolar cautery is greater than 15 cm from the device lead or generator
What is significant stenosis?
Significant stenosis = narrowing of major coronary artery by more than 70% or left main by more than 50%
What can echocardiography detect?
provides a quantitative assessment of global ventricular function, or EF., small pericardial effusions and anatomic cardiac abnormalities, including atrial septal defects (ASDs) and ventricular septal defects (VSDs), aneurysms, and mural thrombi.
What is considered the gold standard for diagnosis of cardiac pathology before most open-heart operations and for definitive lesions of the coronary vessels?
Cardiac catheterization
Lesions that reduce vessel diameter by greater than _____ reducing the cross-sectional area by greater than _____, are considered significant.
Lesions that reduce vessel diameter by greater than 50%, reducing the cross-sectional area by greater than 70%, are considered significant.
What is post-procedure therapy (Dual antiplatelet therapy)?
Aspirin: continue indefinitely
Clopidogrel: continue for minimum 6 months to prevent restenosis
Elective noncardiac surgery should NOT be scheduled within _______ of bare metal stent placement or within ________ of drug eluting stent placement (Hensley)
Elective noncardiac surgery should NOT be scheduled within 1 month of bare metal stent placement or within 6 months of drug eluting stent placement (Hensley)
How long prior to surgery should a patient on beta-blockers take their beta blocker?
24 hours
Recommendations for beta-blocker use
Continue beta blockers in patients previously treated with beta-blockers
Institute between 30 days and at least 1 week before high-risk surgery
Avoid acute initiation of high-dose beta-blocker therapy
Continue beta blockers postoperatively for approximately a month –goal HR 60-65
How are beta blockers cardio protective?
Restore the oxygen supply/demand mismatch
Reduce perioperative ischemia
Redistribute coronary blood flow to subendocardium
Stabilizes plaques
Increases v-fib threshold…makes it harder for v-fib to occur
How are statins cardioprotective?
Enhance endothelial function
Improve atherosclerotic plaque stability
Reduce vascular inflammation
Recommendations for statin use prior to surgery
Institute therapy between 30 days and at least 1 week before high-risk surgery
Continue statin therapy perioperatively
True/False: we routinely have ACE inhibitors held for 1-2 days prior to surgery due to the extreme refractory hypotension that can be associated with ACE inhibitors and volatile anesthetics
True
How long do we hold beta blockers prior to surgery?
we dont
How long do we hold aspirin prior to surgery? (antiplatelet)
7 - 10 days
How long do we hold plavix/brilinta prior to surgery? (antiplatelet)
5 days
How long do we hold effient prior to surgery? (antiplatelet)
7 days
How long do we hold anticoagulants for (pradaxa, xarelto, eliquis)?
1-2 days
