DNURS 835 The cardiac surgical patient Flashcards
What are considered high risk for death/MI surgeries for the cardiac patient?
> 5% risk
Aortic Surgery & Vascular Surgery
- Long surgical procedures with significant volume/blood loss
- Aortic surgery
- Major vascular surgery
- Peripheral vascular surgery
Typically, ortho procedures—hip replacements are longer with high volume/blood loss
What surgeries are intermediate risks for the cardiac patient?
1-5% risk
Intraperitoneal
Transplant
Peripheral Artery Angioplasty
Endovascular Aneurysm Repair
Head & Neck
Neuro/Ortho
Intrathoracic
Major Urologic
What are 2 of the main questions asked in determining functional capacity?
Can you walk 4 blocks w/o stopping?
Can you go up 2 flights of stairs w/o stopping –> if not = 82% risk for postop complications
___ risk surgeries: breast; dental; endoscopic; superficial; endocrine; cataract; gynecological; reconstructive; minor orthopedic; minor urologic
Low risk (< 1% morbidity)
General Risk Factors for CV M&M
- 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
MET Definition
Metabolic Equivalents (METs)
Recognized method of evaluating a patient’s functional capacity
MET is defined as the amount of oxygen consumed while sitting at rest and is defined as 3.5 ml oxygen/kg/min
New York Heart Association Functional Classification of Cardiovascular Disability
This is a standardized means of categorizing the degree of CV disability.
A specific inquiry should be made regarding the presence of dyspnea, chest pain, fatigability, syncope, palpitations and the factors that lead to angina
What is considered Poor Functional Capacity?
1 MET
Self-care
Walking indoors
Walking 1-2 blocks really slow
What is considered Good Functional Capacity?
4 METs
Light Housework
Stairs w/o stopping
Brisk walking
Short run
Light sports
What are the clinical risk factors for CV surgery?
Poor LV Function
CHF
Unstable Angina
Past MI
Age > 65
Obesity
Reoperation
Emegency Surgery
Uncontrolled Illness
Left Ventricular Dysfunction
Active LV failure is the predominant CV risk factor for pts undergoing noncardiac surgery
2 Classifications:
- Preserved EF (>50%)
- Reduced EF (<50%)
Although pts with HF that have a preserved EF have better perioperative outcomes, a diagnosis of HF places the patient at significantly higher risk than other disease processes.
HF is defined as any of the following: Hx of….
- Hx of CHF
- Pulmonary edema
- Paroxysmal dyspnea
- BL rales
- S3 gallop
- CXR showing pulmonary vascular redistribution
What is associated w/ the highest risk for PeriOperative MI?
Unstable Angina
An MI in the past > 6 months increases PeriOp risk of infarction by ______
6%
An MI in the past b/t 3-6 months increases PeriOp risk of infraction by ______
15%
An MI in the past 3 months increases PeriOp risk of infraction by ______
30%
When is the highest risk period for a surgical patient who had an MI?
Within 30 days of the MI –> need to wait at least 4-6 weeks after MI
Which kind of heart stent has a decreased rate of restenosis?
Drug Eluting Stent
How long should Aspirin & Plavix be continued after coronary revascularization?
Aspirin: indefinitely
Plavix: at least 1 yr.
How long should a patient wait before having elective surgery if they’ve had a bare metal stent or drug eluting stend placed?
Bare Metal: 6 weeks
Drug Eluting: 12 months
How long should a patient wait before having elective surgery if they’ve had a bare metal stent or drug eluting stent placed?
Bare Metal: 6 weeks
Drug Eluting: 12 months
What should be obtained for the surgical patient who has valvular stenosis?
Recent Echo to estimate EF
Which valvular disorder poses the greatest risk for a patient undergoing non-cardiac surgery?
Severe Aortic Stenosis w/ cross sectional area < 1 cm2
Which drugs are used for a pharmacologic stress test?
Adenosine & Dobutamine
What makes the risk for Electromagnetic interference low in regards to a patient w/ a pacemaker or AICD?
Device < 10 yrs old
&
Cautery > 15 cm from lead
What are the cardioprotective attributes of statins?
↑Endothelial Function
↑Plaque Stability
↓Vascular Inflammation
When should statins be started before high risk surgeries?
30 days - 1 week before surgery & continue peri-operatively
Why are B-Blockers given for high risk surgeries?
Restore O2 supply/demand mismatch
↓PeriOperative Ischemia
Redistribute blood flow to Subendocardium
Stabilizes Plaques
↑V-Fib Threshold
How should B-Blockers be managed for high risk surgeries?
Start b/t 30 days - 1 week before surgery
Avoid starting high dosage
Continue previous therapy & post-op for a month
HR goal = 60-65
Why are ACE Inhibitors important for the cardiac surgery patient?
↓PeriOperative HF, MI, and Death in pts w/ LV dysfunction
Longer half-life than B-Blockers
How should ACE Inhibitors be managed for cardiac surgery?
Hold 1-2 days before surgery d/t refractory hypotension
May decrease effectiveness of Ephedrine
High risk (>5% morbidity) surgeries for patients with preexisting CV disease: ___ surgery; major ___ surgery; ___ vascular surgery
Aortic surgery; major vascular surgery; peripheral vascular surgery
These surgeries have higher rates of morbidity just based on the procedure alone (not even considering additional patient factors)
___ risk surgeries: intraperitoneal; transplant; carotid; peripheral artery angioplasty; endovascular aneurysm repair (open AAA repair would be HIGH risk); head/neck surgery; major neurologic/orthopedic surgery—i.e.: multi-level fusion surgery, hip repair; intrathoracic—i.e.: lung surgery; major urologic—i.e.: prostatectomy, nephrectomy
Intermediate risk (1-5% morbidity)
___ risk surgeries: breast; dental; endoscopic; superficial; endocrine; cataract; gynecological; reconstructive; minor orthopedic; minor urologic
Low risk (< 1% morbidity)
METs = ___, how we measure a patient’s ___ capacity
Metabolic equivalents, how we measure a patient’s functional capacity
Gold standard of evaluating a patient’s functional capacity (main question we ask patients when doing our pre-op assessment?)
“Are you able to climb two flights of stairs without stopping, regardless of limiting symptoms?”
Inability of patients to climb two flights of stairs without stopping, regardless of limiting symptoms, leads to a ___% increase in risk for cardiopulmonary complications postoperatively
82% increase in risk
1 MET = ___ functional capacity
Poor
Examples = self-care, eating, dressing, using the toilet, walking indoors/around the house, walking 1-2 blocks on level ground at 2-3 mph
4 METs = ___ functional capacity
Good
Examples = 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
Greater than 10 METs = ___ functional capacity
Excellent
Example = strenuous sports
8 clinical risk factors for CV surgery: poor ___ (right/left) ventricular function; ___ heart failure; ___ angina or MI within the past ___ months; age > ___; severe ___ity; reoperation (i.e.: redo CABG); ___ surgery; severe uncontrolled ___ illness (i.e.: COPD or diabetes + noncompliance)
Poor LV function; congestive heart failure; unstable angina or MI within the past 6 months; age > 65; severe obesity; reoperation (i.e.: redo CABG); emergency surgery; severe uncontrolled systemic illness (i.e.: COPD or diabetes + noncompliance)
___ = highest risk factor for perioperative MI
Unstable angina—chest pain that doesn’t go away with nitroglycerin or by stopping activity; unpredictable
Patient with history of MI—MI in the past > ___ months increase periop risk of infarction 6%
> 6 months
Patient with history of MI—MI in the past ___-___ months increase periop risk of infarction 15%
3-6 months
Patient with history of MI—MI in the past ___ months increase periop risk of infarction 30%
Patient with history of MI—highest at risk period for perioperative infarction is within ___ days after an acute MI
Patient with history of MI—highest at risk period for perioperative infarction is within ___ days after an acute MI
30 days
Patient with history of MI—AHA guidelines recommend waiting at least ___-___ weeks after an MI before undergoing elective surgery
4-6 weeks
Elective non-cardiac surgery should NOT be scheduled within ___ weeks after bare metal stent placement
6 weeks
Elective non-cardiac surgery should NOT be scheduled within ___ months after drug eluting stent placement
12 months
Which valvular disorder poses the greatest patient risk for non-cardiac surgery?
Severe aortic stenosis
Associated with a fourteenfold greater incidence of peri-op sudden death
Normal valves can episodically accommodate up to 7 times the normal cardiac output – ex: intense physical exercise
Aortic stenosis is the greatest risk for non-cardiac surgery, especially when the cross sectional area of the valve is less than ___ cm ^ 2
< 1 cm ^ 2–indicates severe aortic stenosis
Peri-operative Arrhythmia evaluation
Must have adequate perioperative evaluation to determine nature of arrhythmia, associated underlying heart disease, and type of antiarrhythmic therapy
Supraventricular arrythmias
Atrial fibrillation (AF) and flutter, the most common SVTs, increase in frequency with increasing age in the presence of organic heart disease
Ventricular arrythmias
Benign ventricular arrhythmias
Potentially malignant ventricular arrhythmias (known heart disease and on antiarrhythmic therapy)
Malignant ventricular arrhythmia (known heart disease, hemodynamic compromise, and possibly family hx of sudden death)
In the absence of cardiac disease, benign ventricular arrhythmias do not carry increased surgical risk
Incidence. While cardiac dysrhythmias are common in patients presenting for cardiac surgery up to ____%, life-threatening dysrhythmias occur less than __% of the time.
Patients with preoperative ventricular arrhythmias associated with LV dysfunction and an EF <30% to 35% are often managed with the prophylactic __________.
75%
1%
implantation of an ICD
Electromagnetic interference risk is low as long as cautery is > ___ cm away from the pacemaker device (~ distance from pacemaker to ___)
> 15 cm away from the pacemaker device (~distance from pacemaker to belly button)
Typically do not need to disable the AICD in these cases because the chance of interference is so low
Intraoperative key point about electromagnetic interference
Interoperative key point:
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
Pre-operative evaluation of Cardiovascular Implantable Electronic Device Pacemaker, Implantable Defibrillators includes the basic steps of…..
- Establish indication for permanent pacemaker (heart block, sinus node dysfunction, cardiomyopathy, etc.)
- Device interrogation prior to
- Determine pacemaker settings and underlying rate/rhythm
Cardiac catheterization – provides definitive information about the ________ and ________ of CAD
Cardiac catheterization – provides definitive information about the distribution and severity of CAD
Indicated for patients with New
York Heart Association class III or IV
Significant stenosis = narrowing of major coronary artery by more than______% or left main by more than ______%
70%
50%
T or F?
EKG alone is not a predictor of peri-op major adverse cardiac events
Used in conjunction with stress test
True
Device interrogation prior to procedure:
Pacemaker should be interrogated within _____ of elective surgery
ICD with in______; but many times, interrogation happens just prior to procedure
Pacemaker should be interrogated within 12 months of elective surgery
ICD with in 6 months
Many times, interrogation happens just prior to procedure
T or F?
Preoperative EKG – exercise stress EKG is valuable for the high-risk patient
Pharmacologic stress test with _________ and __________
True
Adenosine and Dobutamine
Non-Invasive Cardiac Imaging using ETT is used for…..?
Preoperative testing for myocardia ischemia
Exercise tolerance testing (ETT)
Used to evaluate chest pain of unknown etiology
Determine functional capacity and identify significant ischemia or dysrhythmias for risk stratification
ETT is rarely useful as a screening test in asymptomatic patients
Preoperative stress testing can help determine…..
Preoperative stress testing can help determine how much myocardium is “at risk” for ischemia. This information can identify which noncardiac surgical patients may benefit from a preoperative coronary evaluation and possible intervention.
___________ is considered the gold standard for diagnosis of cardiac pathology before most open-heart operations and for definition of lesions of the coronary vessels.
Cardiac Catheterization
Limitations of ETT
Inability to exercise because of systemic disease, particularly PVD.
Abnormal resting ECG precluding ST segment analysis (paced rhythm, left bundle branch block, LV hypertrophy, digoxin therapy).
β-Blocker therapy that prevents the patient from achieving 85% of his or her maximum permissible heart rate.
Pacemakers can mask……
Pacemakers can mask the toxicity of antiarrhythmic drugs, electrolyte disorders, myocardial ischemia and irritability
This class of medications enhances endothelial function; improves atherosclerotic plaque stability; and reduces vascular inflammation
Statins
Statin therapy should be continued perioperatively—T/F?
True
This medication class restores oxygen supply/demand mismatch; reduces perioperative ischemia; redistributes coronary blood flow to subendocardium; stabilizes plaques; increases V Fib threshold
Beta blockers
If patient is on beta blocker, it should be given within ___ hours of surgery
24 hours
ACE inhibitors have a ___ (shorter/longer) half-life than beta blockers
Longer half-life
Hold ACE inhibitors ___-___ days prior to surgery d/t extreme refractory ___tension that occurs when combined with volatile anesthetics
1-2 days prior to surgery d/t extreme refractory hypotension that occurs when combined with volatile anesthetics
Abrupt withdrawal of β-blockers can lead to a rebound phenomenon, manifested as _________, __________, _________, __________, and even ______, _________ _________, and ________ __________.
Nervousness, tachycardia, palpitations, hypertension, and even MI, ventricular arrhythmias, and sudden death.
Preoperative treatment with β-blocking agents reduces
perioperative tachycardia and lowers the incidence of ischemic events
Cardioprotective Pharmacotherapy of Beta Blockers
- Restore the oxygen supply/demand mismatch
- Reduce perioperative ischemia
- Redistribute coronary blood flow to the subendocardium
- Stabilizes plaques
- Increases v-fib threshold (Harder for Vfib to occur)
Beta Blocker Recommendations
- 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
Hold parameters for Antiplatelets:
Aspirin
Plavix/brilinta
Effient
Antiplatelet
Aspirin – 7-10 days
Plavix/brilinta – 5 days
Effient – 7 days
Hold parameters for Anticoagulant:
Pradaxa, Xarelto, Eliquis
1-2 days
Antihypertensives
Preoperatively, chronic antihypertensive medications should usually be continued until ________________ and be begun again as soon as the patient is _________________.
Preoperatively, chronic antihypertensive medications should usually be continued until the morning of surgery and be begun again as soon as the patient is hemodynamically stable postoperatively.
Antihypertensives
Continuation of ____________ and ___________ until the morning of surgery are particularly important because of the risks of rebound hypertension with sudden withdrawal of these drugs.
β-blockers and α-2 agonists
Antidysrhythmics
Therapy for dysrhythmias should be continued perioperatively? T or F
