2. cardiac assessment 3/6

Question 1

what is the % risk for MI in each classification:

1. high risk?
2. intermediate risk?
3. low risk?

Answer 1

1. high= 12-20%
2. intermediate= 3-7%
3. low= <3%

Question 2

1. Peak incidence of a perioperative MI occurs within what time frame?
2. what percent of MI is pre op?
3. what percent if intraop?
4. what percent if postop?

Answer 2

1.within 48 hours of surgery, often following a
circadian rhythm and when cortisol levels peak (0400 am)
2. 20% preop
3. 25% intraop
4. 41% postop

Question 3

1. why might a periopertive MI be hard to diagnose?

2. how much is the risk of cardiac events increased in an emergent surgery vs. elective?

Answer 3

1. Clinically, silent 90% of the time; Ischemia often is not associated with tachycardia or even ECG changes
2. Patients that have emergent surgery are 2-5x more likely to have adverse cardiac events compared to pts having elective cases

Question 4

what are 5 of the most important predictors of cardiac risk:

Question 5

what should you do if the patient has a recent or “remote” (past) history of an MI?

Answer 5

Delay elective surgery for about 6 months after an MI!

Question 6

Patient Group Infarction Rate: what is the risk of MI:

1. All surgical patients?
2. Prior MI (>6 months ago)?
3. Recent MI (4-6 months ago)?
4. Recent MI (3 months ago)?
5. History of CABG surgery ?

Answer 6

Patient Group Infarction Rate

1. All surgical patients =0.2%
2. Prior MI (>6 months ago) =6%
3. Recent MI (4-6 months ago) =15%
4. Recent MI (3 months ago) =30%
5. History of CABG surgery =1.2%

Question 7

so the risk margin of having an MI 3 months ago vs. >6 months ago is?

Answer 7

> 6 months ago= 6% chance; 3 months ago=30% chance:

The risk is 5x higher!!!

Question 8

Duration of operation and site have an effect as well on MI rates.

1. what is the %chance for upper abdominal or intrathoracic procedure greater than 3 hours vs. less than 3 hours?
2. what is the % chance for other operative sites with same criteria?

Answer 8

1. Intrathroracic or upper abdominal:

>3 hours: 15.9% ; 3 hours=3.8%; <3 hours: 3.6%

Question 9

What 4 things that we are concerned about in the cardiac patient

Question 10

1. what does the ASA status help identify?

2. what is the issue with it?

Answer 10

1. Classification of physical status and functional capacity (1-6)
   E added for emergency surgeries: E considered to be pt’s in poorer condition and potentially worse outcome
2. it is subjective

Question 11

1. what assessment tool came along in 1977 & 1983 that was better than asa for cardiac risk?
2. how was it broken down?

Answer 11

1. Goldman Cardiac Risk index
2. 9 risk factors, each factor assigned points with Multifactorial scoring index to estimate cardiac risk
   
   • S3 or JVD =11
   • MI within 6 mos =10
   • > 5 PVCs/min =7
   • PACs or non-sinus =7
   • Age>70 =5
   • Emergency =4
   • Chest, abd, aorta =3
   • Valvular stenosis =3
   • Poor general health =3

Question 12

How did the Destsky risk index improve on Goldman’s?

Answer 12

added CHF and angina to the list

Question 13

1. when was the ACC/AHA guideline created ?

2. what does it look at?

Answer 13

1. 1996, revised in 2002, 2006
2. the ACC/AHA guidelines look at the 4 things above, then applies them systematically:
   o Step #1: Is the surgery emergent?
   o Step #2: Prior revascularization?
   o Step #3: Recent Coronary Evaluation?
   o Step #4: Clinical Predictors (major, intermediate, and low) – these indicate the highest correlation to a perioperative event

Question 14

according to ACC/AHA:

What are considered “Major clinical predictors” of surgical risk?

Answer 14

Major “clinical” predictors of surgical risk=
• Unstable coronary syndromes
• Decompensated CHF
• Significant arrhythmias
• Severe valvular disease

Question 15

according to ACC/AHA:

what are considered “Intermediate clinical predictors” of surgical risk?

Answer 15

Intermediate “clinical” predictors of surgical risk
• Mild angina pectoralis
• Prior MI
• Compensated or prior CHF
• Diabetes mellitus
• Renal insufficiency

Question 16

according to ACC/AHA:

What are considered “Minor clinical predictors” of surgical risk

Answer 16

Minor “clinical” predictors of surgical risk
• Advanced age
• Abnormal ECG
• Rhythm other than sinus
• History of stroke
• Uncontrolled systemic hypertension
• Low functional capacity

Question 17

1. What is Functional Capacity?
2. what is an example of METs
3. why use METS?

Answer 17

1. Measured in Metabolic Equivalent of Tasks: “METs”
2. Oxygen consumption of a 70 kg, 40 year old man at rest is 3.5 mL/kg per minute, or 1 MET. Compare to running 10.9 mph = 18
   METS.
3. a) A reliable predictor of long term cardiac morbidity
   b) Helps determine of additional testing is necessary

Question 18

Examples of Common activities and METs:
1. how many mets is Eating, dressing?
2. how many mets is light house work, walking 2-3 mph etc?
3. how many mets is climbing a flight of stairs?
4. how many mets is climbing a flight of stairs carrying groceries?
5. how many mets is Moderate cycling, climbing hills, heavy
housework?
6. how many mets is Swimming, skiing, singles tennis, running?

Answer 18

1.

Question 19

at what MET level should we be concerned prior to surgery (considered poor functional capacity)?

Answer 19

<4 METS

Question 20

So, what is needed if the patient has ANY 2 of these factors?

• Angina
• CHF
• DM
• previous MI
• Poor functional capacity (< 4 METS)

Answer 20

additional testing