Post-op Complications

Question 1

What is the definition of an MI?

Answer 1

Rise and fall of troponin above 99th percentile plus one of the following: 1) symptoms 2) ECG evidence (st-t change, LBBB, new q waves) 3) imaging showing loss of viable myocardium or wall motion abnormality

Question 2

What is the difference between a type 1 and 2 MI?

Answer 2

Type 1 - spontaneous due to an unstable coronary plaque

Type 2 - secondary to an extracardiac cause (demand ischemia)

Question 3

What is the difference between STEMI and NSTEMI?

Answer 3

STEMI - major coronary territory or an area that has insufficient collaterals - requires urgent PCI.

NSTEMI - supplies smaller coronary territories or areas supplied by collaterals, PCI only if hemodynamically unstable or worsening symptoms

Question 4

What percentage of vascular surgery patients have post-op MI (defined by elevated tropnonin?)

Answer 4

25%

Question 5

What is unstable angina?

Answer 5

Recurrent or new typical chest pain with no evidence of serum troponin elevation (if trop elevated then its defined as an MI)

Question 6

What are 3 types of heart failure?

Answer 6

1) Heart failured with reduced EF (systolic heart failure) - usually due to MI
2) Heart fialure with sustained EF (diastolic heart failure) - usually due to prolonged HTN and LVH
3) Right ventricular heart failure - usually due to LV failure and severe mitral valve disease or severe lung disease (cor pulmonale)

Question 7

Which vascular procedure has the highest risk of cardiac morbidity?

Answer 7

Aortic surgery (EVAR 1%, Open 15%)

Question 8

What is the cardiac event rate for lower extremity vascular surgery?

Answer 8

Depends on symptoms. CLI = 10% vs claudication 3%

Question 9

What is the risk of periop cardiac morbidity after carotid surgery?

Answer 9

3% (1.5% with stenting)

Question 10

What do pathologic q waves on an EKG represent?

Answer 10

Old MI, more leads = wider area of infarct

Question 11

What does tall R waves and wide QRS complexes (with or without ST changes), and inverted T waves represent?

Answer 11

myocardial hypertrophy or dilation

Question 12

What is the RCRI?

Answer 12

Revised cardiac risk index - 6 independent risk factors:

1-history of cardiac disease

2- history of chf

3- insulin therapy

4-chronic renal impairment

5-cerebrovascular disease

6-major surgery

Question 13

According to the ACC/AHA, which patients should undergo noninvasive stress testing?

Answer 13

Patients with limited functional capacity < 4 METS (unable to climb 2 flights of stairs without chest pain or shortness of breath)

Question 14

What did the CARP trial study?

Answer 14

The benefit of prophylactic PCI/CABG in patients with >70% coronary artery stenoses prior to surgery. There were no differences between patients who underwent coronary revasc compared with patients who did not.

Question 15

What are 2 major limitations of the CARP trial?

Answer 15

1) Did not rigorously follow ACC/AHA screening and a minority of patients had evidence of severe ischemia on noninvasive testing - underpowered
2) Excluded patients wit left main disease (a population who may benefit from coronary revasc)

Question 16

Should you give patients with CAD betablockade before periop?

Answer 16

No - POISE showed doubling of post-op strokes and cochrane review showed no clear evidence that periop prophylactic betablockade improved cardiac morbidity.

Question 17

How long after PCI/stent should you delay elective non cardiac surgery?

Answer 17

30 days afer BMS and optimally 6 months after DES

Question 18

How do you manage a suspected post-op NSTEMI?

Answer 18

1 - consult cardio

2- control heart rate and blood pressure with beta blockers/calcium channel blockers (if sbp > 100)

3- control pain to avoid tachycardia

4-treat tachyarrythmia (aflutter afib)

5- correct anemia, hypoxemia, follow trop

Question 19

Name 5 common post-op respiratory complications

Answer 19

1-PE

2-pulmonary edema

3-aspiration pneumonia

4-pleural effusion

5-exacerbation of underlying disease

(ARDS, Bronchitis, resp failure, TRALI)

Question 20

Name 5 patient related risk factors that put patients at higher risk of pulmonary complications

Answer 20

1-smoking

2-recent resp infection

3-OSA

4-COPD

5-CHF

(Functional dependence, age, ASA 2+, poorly controlled asthma)

Question 21

Name 5 procedure-related risk factors for post-op pulmonary complications

Answer 21

1-longer than 2h

2-peri-op blood transfusion

3-type of anesthesia (local/general)

4-open surgery (over endo)

5-surgical site (aortic confers highest risk)

6- emergency surgery

Question 22

Name 4 laboratory test risk factors for post-op pulmonary complications

Answer 22

1-anemia hgb < 100

2-spO2 < 90%

3-albumin < 35

4-BUN < 21

Question 23

What percentage of anesthetized patients have atelectasis?

Answer 23

Up to 90%

Question 24

What is the most common pathogen in ventilator associated pneumonia?

Answer 24

Staph aureus

Question 25

What parameters are used in the clinical pulmonary infection score for ventilator associated pneumonia?

Answer 25

1 - temp 2 - WBC 3 - Sputum character 4 - CXR 5 - Culture of ET suction 6 - oxygenation (PaO2/FiO2)

Question 26

What is the Berlin definition of ARDS?

Answer 26

1- Time: Within 1 week of known clinical insult/worsening resp symptoms 2 - CXR: bilateral opacities 3 - Edema cause: Not fully explained by cardiac/fluid overload 4- Oxygenation - need echo to exclude hydrostatic edema

Question 27

What is cisatracurium used for with respect to resp failure?

Answer 27

Neuromuscular blockade - IV infusion for 48 h can help patients with ARDS and a PaO2:FiO2 less than 150.

Question 28

Name the associated causes of renal failure

Answer 28

Question 29

Name the associated causes of renal failure

Answer 29

Question 30

Name the associated causes of renal failure

Answer 30

Question 31

Name the associated causes of renal failure

Answer 31

Question 32

Name the associated causes of renal failure

Answer 32

Question 33

Name the associated causes of renal failure

Answer 33

Question 34

Name the associated causes of renal failure

Answer 34

Question 35

Name the associated causes of renal failure

Answer 35

Question 36

Name the associated causes of renal failure

Answer 36

Question 37

What is ischemic monomelic neuropathy?

Answer 37

A rare nerve injury following acute limb malperfusion, characterized by multiple distal axonal infarctoins resulting in motor and sensory mononeuropathies

Question 38

List 4 common causes of unilateral neuropathy

Answer 38

1. Entrapment 2. Trauma 3. Ischemia 4. Vasculitis

Question 39

List 7 common causes of bilateral neuropathy

Answer 39

1. Metabolic (diabetes) 2. Toxic (etoh, drugs) 3. Vasculitis 4. Vitamin deficiency 5. HIV 6. Monoclonal gammopathies 7. Inflammatory or vasculitis

Question 40

What are 3 first-line therapy of drug classes for treating neuropathic pain?

Answer 40

1. tricyclic antidepressants: amytriptiline 2. gabapentin: doesn't work for everyone, takes weeks to take effect 3. SSNRI duloxetine and venlafaxine

Question 41

What is the rate of axonal regeneration?

Answer 41

1 mm per day

Question 42

What are the 5 main terminal branches from the brachial plexus of the upper extremity

Answer 42

1. musculocutaneous 2. median 3. ulnar 4. axillary nerve 5. radial

Question 43

Which nerves are at risk during axillary dissections?

Answer 43

1. musculocutaneous 2. median 3. ulnar

Question 44

Which nerve do you have to watch out for in brachial dissections?

Answer 44

Median

Question 45

Which nerve lies deep to the basilic vein?

Answer 45

Ulnar

Question 46

What are the clinical findings of an axillary nerve injury?

Answer 46

Weak shoulder abduction and sensory deficit of deltoid

Question 47

What are the findings associated with median nerve injury?

Answer 47

Sensory deficit on radial side of D1234. Weakness in thenar muscles.

Question 48

What are the findings associated with an ulnar nerve injury?

Answer 48

Sensory numbness of 5th digit and weak abduction and adduction of fingers

Question 49

What are clinical findings associated with femoral nerve injury?

Answer 49

Weakness or paralysis of quads, difficulty with knee extension, reduced patellar reflex, numbness along the course of the saphenous nerve on anteriomedial aspect of thigh

Question 50

What are the phases of wound healing?

Answer 50

1 - inflammation 2 - prolipheration 3 - epithelialization 4 - remodelling

Question 51

How can you prevent contrast induced nephropathy?

Answer 51

1. Infusion of bicarb (better than saline in one RCT, NNT 8). Thought to alkalinze renal tubular fluid. 2. Hold metformin 48 h before contrast and hold diauretics.

Question 52

What is the definition of contrast induced nephropathy?

Answer 52

An 25% increase in creatinine within 3 days of contrast admin with no alternate cause

Question 53

What are 4 risk factors for developing contrast induced nephropathy?

Answer 53

1. Pre-existing renal failure (intra-arterial GFR \< 60, IV GFR \< 40) 2. Diabetes 3. Volume \> 5 ml/kg 4. Second contrast dose within 48 hours