Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
74 Cards in this Set
- Front
- Back
|
When are you able to hear the aortic or pulmonic valve opening and what does it sound like?
|
dilated aorta, aortic valve disease, dilated pulmonary artery, pulmonary stenosis, pulm htn; early systolic ejection click
|
|
|
What causes S1 and S2?
|
S1(mitral and tricuspid valve closure)
S2(aortic and pulmonic valve closure |
|
|
What is the typical X and Y axis of the Frank-Starling curve?
|
X axis: preload(LVEDV or pressure, wedge pressure); Y axis: work(stroke volume, cardiac output)
|
|
|
What does a frank starling curve shifted down and to the right indicate?
|
decreased contractility(myocardial ischemia, infarction, CHF);
|
|
|
What does a frank starling curve shifted up and to the left indicate?
|
improved ventricular performance(the capacity for more work and better contractility)
|
|
|
What happens to the frank starling curve if you add an inotrope such as dopamine, epi, dobutamine?
|
increase work, mild decrease in preload
|
|
|
What happens to the frank starling curve if you add nitroglycerin plus an inotrope?
|
decrease preload, increase work
|
|
|
What happens to the frank starling curve if you add nitroglycerin?
|
decrease preload
|
|
|
Where do the coronary arteries arise from?
|
sinuses at the root of the aorta
|
|
|
What area of the heart is most prone to ischemia?
|
LV subendocardium(compressed during systole)
|
|
|
Why are patient's with aortic stenosis more prone to ischemia?
|
very high LV pressures are needed to achieve CO, coronary vessels are severely compressed during systole and this can lead to ischemia; coronary perfusion pressure is equal to aortic diastolic pressure minus LVEDP
|
|
|
How does hypoxia affect the coronary circulation?
|
vasodilation; causes production of CO2, H+, lactate, prostaglandins, adenosine
|
|
|
What neural factors affect coronary circulation?
|
stimulation of vagal fibers dilates the coronaries
|
|
|
What determines right and left ventricular perfusion?
|
right ventricular perfusion depends on MAP; left ventricular subendocardial perfusion depends on diastolic arterial pressure
|
|
|
What patient's should receive periop beta blockade?
|
known CAD(hx of MI, current angina, positive stress test), any two of the following: >50yo, htn, current smoker, HLD, diabetes
|
|
|
What patients should not receive periop beta blockade?
|
known sensitivity to beta blockers, second or third degree heart block, acute CHF, acute bronchospasm, SBP<100, HR<60, unstable
|
|
|
What is the bainbridge reflux?
|
increased RAP leads to increased HR, by afferent inhibition of the parasympathetic nervous system
|
|
|
What is the Bezold-Jarisch reflux?
|
eponym for triad of responses: apnea bradycardia and hypotension that occur when certain noxious stimuli are sensed by chemo and mechano receptors in the LV
|
|
|
What nerves make up the afferent component of the baroreceptor reflux at the carotid sinus and the aortic arch?
|
carotid sinus: CN IX
aortic arch: CN X |
|
|
What do chemoreceptors in the carotid and aortic bodies respond to?
|
changes in pH and PaO2(in acidotic states or PaO2<50, resp center is stimulated via CNX, IX and and vent drive increase while HR and myocardial contractility decrease)
|
|
|
What is the valsalva maneuver?
|
forced expiration against a closed glottis leading to increased intrathoracic pressure, decreased venous return, increased CVP-> decreased CO, BP
|
|
|
What causes the cushing reflex?
|
increased ICP causes cerebral ischemia leads to activation of SNS and initially HTN, tachycardia, and increased myocardial contractility; later the HTN results in refux bradycardia
|
|
|
How does the administration of atropine affect the occulocardiac reflux?
|
reduces the incidence but does not prevent the reflux
|
|
|
What determines myocardial oxygen demand?
|
HR> myocardial wall tension(afterload>preload)
|
|
|
What determines myocardial oxygen content?
|
coronary blood flow x arterial oxygen content
|
|
|
What determines coronary perfusion pressure?
|
aortic diastolic pressure-LVEDP
|
|
|
What can you decipher from lead II and V5?
|
II dysrhythmias and inferior wall ischemia
V5 ant and lateral ischemia |
|
|
How good is the PA catheter at detecting ischemia?
|
neither sensitive nor specific
|
|
|
Before treating myocardial ischemia with medications what should do?
|
correct hypovolemia, hypotension, and anemia
|
|
|
What are the goals of treating intraop myocardial ischemia?
|
increase myocardial oxygen supply(increase O2 content by increasing FiO2 and treating anemia, increase coronary perfusion pressure, increase subendocardial blood flow with nitroglycerin), decrease myocardial oxygen demand by treating HR, preload and afterload(preload with nitroglycerin and HR with beta blocker)
|
|
|
What vessels are usually involved with triple vessel CAD?
|
RCA, left circumflex, LAD
|
|
|
What are indications for CABG?
|
high grade left main disease or triple vessel disease, severe angina no relieved with medications, unstable angina or episodes of prolonged myocardial ischemia
|
|
|
What is the peak time to reinfarction postop?
|
3-5 days
|
|
|
What factors increases the risk of post op myocardial reinfarction?
|
previous MI in the past 6months, CHF, unstable angina, prolonged thoracic and upper abdominal surgery, preop hypertension, intraop hypotension,
|
|
|
What are pulmonary manifestations of CHF?
|
pink frothy fluid in ETT, increase PAP, decreased SaO2
|
|
|
How can you treat CHF?
|
restrict fluids, lasix, reduce preload and pulmonary blood flow with nitroglycerin and morphine, improve LV fxn with inotropes, optimize blood pressure and afterload with phenylephrine, hydralazine and nitroprusside
|
|
|
Can you use pacing for afib or aflutter?
|
pacing is effective for aflutter but not for afib
|
|
|
Why should you avoid lidocaine with afib?
|
increases A-V conductance, and may lead to accelerated ventricular response
|
|
|
Should you continue digitalis during surgery?
|
if CHF is severe it should be continued
|
|
|
What are the manifestations of digitalis toxicity?
|
N/V, AV block, ventricular arrhythmias, vfib
|
|
|
how do you treat dysrrhythmias associated with digitalis toxicity?
|
lidocaine, phenytoin, potassium(avoid D/C shock if suspect dig toxicity)
|
|
|
What causes or predisposes to digitalis toxicity?
|
hypokalemia, hypothyroid, hypomagnesemia, hypercalcemia
|
|
|
What are complications of protamine administration?
|
myocardial depression, histamine release(systemic vasodilation, flushing, severe pulmonary vasoconstriction, bronchospasm) anaphylactic or anaphylactoid reactions; life threatening pulmonary constriction is a type II protamine reaction)
|
|
|
What is the difference between esophageal and rectal temperature during cooling and rewarming during CPB?
|
esophageal represents core temp and rectal represents peripheral temp, during cooling/rewarming with pump oxygenator esophageal temp changes rapidly; during surface cooling rewarming rectal temp changes rapidly
|
|
|
How does heparin work?
|
acts indirectly by a cofactor(antithrombin III) which neutralizes IX, X, XI, and inactivates thrombin preventing it's action on fibrinogen(acts on both intrinsic and extrinsic pathways so both PT and PTT are prolonged)
|
|
|
What is the half life of heparin?
|
about 1hr
|
|
|
When are heparin requirements reduced or increased?
|
reduced: hypothermia, renal, liver disease(prolonged effect)
increased: pulmonary embolic disease |
|
|
Why does protamine antagonize heparin?
|
heparin is a stong acid and protamine a strong base
|
|
|
What is the dose of heparin for CPB?
|
3mg/kg(300u/kg)
|
|
|
When should you redose heparin during CPB?
|
2 hrs after giving initial dose give another 1mg/kg(100u/kg)
|
|
|
What is the normal ACT and what should it be on CPB?
|
normal: 120-150s
CPB: around 480s |
|
|
What is an advantage and disadvantage of hemodilation for CPB?
|
advantage: increases microcirculation by decreasing blood viscosity
disadvantage: decreases O2 carrying capacity |
|
|
How do you treat hypotension during CPB?
|
if thought to be due to low CO increase pump flow rate
if thought to be due to low SVR give phenylephrine |
|
|
How should you treat hypertension during CPB?
|
increase volatile dose, or start nitroprusside
|
|
|
What are pump flow rates at normothermia?
|
2-3L/min/m2
|
|
|
How does hypothermia or hemodilulation affect pump flow rate requirement?
|
with hypothermia you can decrease flow rate, with hemodilution you'll need to increase flow rate
|
|
|
How is the action of muscle relaxant affected during CPB?
|
prolonged
|
|
|
How is perfusion best monitored on CPB?
|
measuring urine output, assessing for presence of acidosis, evaluating MvO2
|
|
|
What rectal and esophageal temperature should be obtained before discontinuation of CPB?
|
esophageal temp 37, rectal temp 33
|
|
|
What are causes of heart block?
|
drugs(quinidine, digitalis, procainamide, propranolol), conduction tissue disease(Lenegre's disease), congenital block, cardiac tissue disease(CAD with ischemia, myocarditis, cardiomyopathy), increased vagal tone
|
|
|
On EKG how do you tell if there is a unifascicular block?
|
LA hemiblock: LAD with RBBB
left posterior hemiblock: RAD with RBBB |
|
|
What are causes of tamponade?
|
TIPS: trauma, infection, perforation of LV byp PAC or CVC, special condition such as collagen or viral disease or chronic renal failure
|
|
|
What are the anesthesia goals during tamponade?
|
full, fast, and tight
|
|
|
What are the typical cardiac pressures during tamponade?
|
increase in diastolic filling pressures across the heart, all diastolic filling pressures equalize to about 20mm Hg
|
|
|
If hypotension occurs in a patient with tamponade what should you do?
|
temporize with fluids, inotropes, trendelenburg positioning, and 100% O2, minimize positive pressure ventilation(if tamponade severe)
|
|
|
What are cardiac medications of choice in patient's with tamponade?
|
dopamine, dobutamine, maintain CO and SVR
|
|
|
What are EKG manifestations of impulses conducted down an accessory pathway such as kent's?
|
short pr interval, wide QRS complex, delta wave
|
|
|
What is the management for Afib in the setting of WPW?
|
procainamide-prolongs the refractory period of accessory pathways, cardioversion is necessary if patient is hemodynamically unstable
|
|
|
What is the management for SVT?
|
vagal maneuvers, adenosine, other drugs(esmolol, procainamide), overdrive pacing, cardioversion
|
|
|
What are anesthetic considerations of patients with WPW?
|
avoid sympathetic stimulation(hypotension, pain, medications), avoid digoxin(enhances cardiac conduction through accessory pathways), atropine is not contraindicated but scopolamine and glycopyrrolate may be better since their chronotropy is less
|
|
|
What is the difference on EKG between polymorphic Vtach and torsades?
|
torsades has prolonged QT intervals
|
|
|
What is the treatment of torsades with unstable hemodynamics?
|
cardioversion, correct electrolytes abn, discontinue responsible drugs
|
|
|
What is the drug of choice of treatment of all ventricular dysrhythmias except those with prolonged QT intervals and torsades?
|
lidocaine
|
|
|
How do you calculate stroke volume index? What's normal?
|
CI/HR x 1000cc/beat/m2; 35-48mL/beat/m2
|
