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Name 6 risk factors for post operative renal dysfunction

Radiologic contrast
complex surgery (AVR + CABG)
ACE inhibitor
pre-operative renal dysfunction


What type of analgesic should be avoided post op


They interfere with prostaglandin function of the kidney


Name treatments for Hyperkalemia

1 gram of Calcium chloride IV
50 meq of Sodium Bicarbonate
10 u of Humulin R IV and 50 ml of D5W
30 gm po Kayexalate


What is malignant hyperthermia

Autosomial dominant with variable penetrance genetic disorder that results in increased skeletal muscle metabolism and CO2 production--hyperthermia/VT/renal failure


What agents can trigger Malignant Hyperthermia and what is the pathophysiology

Inhaled anesthestics (Halthothane, isoflurane)
Possible association with ketamine

*impaired reuptake of inonized calcium from cytsol in the SR


List 4 viability scans

Myocardial perfusion imaging
thallium or technetium
Dobutamine echocardiography


What is CHILD classification of liver failure and what is the mortality of patient with CHILD B

Based on 5 parameters
A is 5-6
B is 7-9
C 10 to 15
CHILD A is 0 to 3%
CHILD B is 40 to 80%
CHILD C is 100%


In patients with cirrhosis of the liver classified as CHILD B what is the mortality associated with a cardiac procedure involved the use of bypass

more then 70%


3 findings on stress thallium that an predict benefit of revascularization

Large reversible defect (which is also caused moderate-severe inducible ischmie, > 10 % of myocardium
Absence of fixed defects
Presence (and number of segments) of viable myocardium


What are contraindications to Dobutamine

Ventricular arrhythmias
Recent myocardial infarctions (1 to 3 days)
Acute coronary syndrome
Hemodynamically significant left ventricular outflow tract obstruction
Aortic aneurysm or aortic dissection
systemic hypertension


What is a dobutamine stress echo

Measure inotropic reserve of dysfunctional, but viable myocardium

viable myocardium shows improved regional contractile function

contractile reserve is independent of the severity of the coronary artery disease

mitral inflow pattern---early diastolic deceleration time (DT) of > 150 msec correlates with improvement after CABG and greater survival.

End-diastolic wall thickness of < .6 cm indicates non-viable segment


List 4 viability studies in order of accuracy

PET imaging
highest sensitivity
more sensitive than Dom echo
excellent at predicting benefit from revascularization
Dobutamine stress echo

Dobutamine MRI


How does thallium myocardial perfusion imaging for viability work

Thallium is take up by viable (living) myocytes (requires NA/K ATPase)
reflection of both perfusion and viability
Current protocols image at stress..redistribution..and reinjection (18 to 24 hours)
defect present in stress that recovers at late imaging indicates viability


List myocardial perfusion end points that are adverse predictors of future cardiac events

Large defect size > 20 percent of the left ventricle
defects in more than 1 coronary artery territor suggestive of multivessel disease
major nonreversible defects
transient or fixed left ventricular cavity dilation
resting left ventricular ejection fraction < 40 percent
increase lung uptake up thallium


What are risk factors for protamine reactions

history of a protamine allergy
Allergy to fish products
Previous exposure to protamine, even without a reaction
Use of NPH insulin
Prior vasectomy (immunologic exposure to sperm proteins after breakeage of the pats blood-sperm barrier.
Any allergy to other meds


What is risk of stroke per degree of carotid stenosis

<50% it's a 2% risk
50 to 80% it's about 7.5%
> 80% it's about 11%
Unilateral occlusions it's about 11%

Poor correlation between degree of audible bruit and the degree of carotid stenosis


What is mechanism of peri-operative stroke with carotid stenosis

Emboli from carotid plaque
Loss of pulsatile flow or inadequate perfusion pressure on bypass may lead to diminished flow distal to stenosis leading to "watershed stroke"
Prothrombotic state post-op leads to destabilization of previously asymptomatic carotid stensosis (as > 50% of cases occur > 24 hours post op)


Who should undergo carotid screening

Age > 65
Left main disease
Peripheral vascular disease
History of TIA/Stroke
Carotid bruit on exam
Prior carotid endarectomy


What are the important outcomes from the carotid u/s to understand

1. Peak systolic velocity (PSV)
2. End-diastolic velocity
3. Ratio between PSV in the internal carotid artery and the proximal common carotid artery (ICA/CCA ratio)
This ratio correct for baseline variation in hemodynamics (such as CO)
a ratio > 4 is equal to > 70%


What are options for carotid endarterctomy and CABG

Staged: CEA 1st--then 1 to 5 days after CABG (usually for those with less critical coronary disease

Combined: when severe CAD and would not tolerate CEA. Symptomatic for both lesion s

Reverse-staged: CABG then carotid--high rate of stroke (14%) while mortality is the same


What are AHA guidelines for CEA before CABG or concomitant

Class IIa

Symptomatic carotid artery disease or asymptomatic disease but stenosis of > 80% unilateral or bilateral


A patient presenting with MI. What are effects of timing on myocardium

1. < 20 minutes of occlusion: reversible cellular damage and dpressed function with subsequent myocardial stunning
2. > 40 min but < 3 hours. If reperfusion happens, 60 to 70% of ultimate infarct is salvageable
3. > 3 hours but < 6 hours: salvageable myocardium decreases to 10%
4. > 6 hours resulting in trans-myocardial infarction


List parameters of cardiogenic shock

SBP < 80 mmHg
PCWP > 18
u/o < 20cc/hr
metal state changes
peripheral vasoconstriction with cold extremities
CI < 1.8
SVR < 200 dyn


What is prevalence and outcomes of presenting in SHOCK

most common cause of in-hospital mortality following MI
Mortality is 80%
Incidence in MI is 2.4 to 12%
results from loss of at least 40% of left ventricle


What is definition of NSTEMI

chest pain > 10 minutes
ST-segment depression > 0.5 mm
ST-segment elevation 0.6mm to 1.0mm
T-wave inversion > 1 mm
Positive troponin
or history of unstable angina in a pt with CAD risk factors


Classify athersclerosis of the aorta

Type 1: circumferential calcification "Porcelain aorta"
Type 2: Diffuse intimal thickening with ragged friable edges. Unreliable palptation, easy to identify on TEE or epiaortic scan
Type 3: Intramural liquid debris. The most difficult to find by palpation or TEE. Best seen on epiaortic scan

An other classification used in TEE or epiaortic
Grade 1: normal or mild, wall< 2 mm
Grade 2: thickening 2-3 mm
Grade 3: atheromatous protrusion < 5 mm
Grade 4: atheromatous protrusion > 5 mm
Grade 5: mobile plaque


What is a grading system for Epi-aortic scanning

Normal no intimal thickening
Mild < 3 mm without irregularities
Moderate > 4 mm with diffifuse irregularities and or calcification
Severe > 5 mm intimal thickening and or large mobile debris and ulcerated pla ques and thrombi


Describe role for pulmonary function test in preop

Help only in highlighting the degree of risk but do not provide definitive risk assessment for post operative complications.
FEV1 that is more than two standard deviations less then predicted is usually associated with a prohibitively high risk for pulmonary complications


Patient with post op AVR having hemolysis. What are tests that should be performed

Serum haptoglobin * best test*
Indirect bilirubin
peripheral smear
urine free hemoglobin
urine hemosiderin


What pulmonary function tests are associated with high risk postoperative respiratory failure

P02 < 60 on room air
PC02 if > 60
FEV1 < 65% of VC
FEV 1 < 1 -1.5 L
DLCO < 50% predicted
Vo2 max > 10 cc/kg, the best predictor but rarely measured
Failure to respond to broncho-dilators


Interpreting pulmonary function testing

The most important spirometric maneuver is the FVC. To measure FVC, the pt inhales maximally, then exhales as rapidly and as completely as possible.
Normal lungs generally can empty more than 80 percent of their volume in six seconds or less. The forced expiratory volume in one second (FEV1) is the volume of air exhaled in the first second of the FVC maneuver. The FEV1/FVC ratio is expressed as a percentage


How to distinguish between restrictive and obstructive pulmonary disorders

When the FVC and FEV1 are decreased, the distinction between an obstructive and restrictive ventilatory pattern depends on the absolute FEV1/FVC ratio.

If the absolute FEV1/FVC ratio is normal or increased, a restrictive ventilatory impairment

A reduced FEV1 and absolute FEV1/FVC ratio indicates an obstructive ventilatory pattern, and bronchodilator challenge testing is recommended to detect patients with reversible airway obstruction (e.g., asthma).

*use 0.7 as the FEV1/FVC ratio that is "normal"


What are parameters of bedside spirometry that indicate high risk

FEV1 < 70% predicted

FEVc < 70 % predicted

FEV1/FVC ratio of < 65%


What is definition of Cardiogenic Shock

BP systolic < 80mmHg mean < 60mmHg
CI < 2 L (with adquate filling)
LAP and/or RAP > 20

Clinical manifestation of low cardiac output
decreased peripheral perfusion (pulses, cool, mottled)
restlessness, confusion, decreased mentation
urine output < 20-30 cc/hr


In patients with pre-existing chronic renal failure and dialysis

a. What is the expected in hospital mortality associated with CABG

b. What is the two year survival (including mortality of all causese)

8- 13%

50 to 60%


In patients with pre-existing chronic renal failure and dialysis
What is the expected in hospital mortality associated withe coronary artery bypass surgery
What is the two year survival (including mortality of all causes)

8 - 13%

50 to 60%

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