Quiz 3: Positive Inotropes and Myocardial Oxygen Balance Flashcards
During shock there is an increase in _______ metabolism which creates a more acidic pH and increases _____.
- anaerobic
- Lactate
What are the three types of shock?
- Septic
- Hypovolemic
- Cardiogenic
What type of hemodynamic would you see with septic shock?
INCREASE
-Cardiac Index
DECREASE
- PCWP
- SVR
What type of hemodynamic changes would you see with hypovolemic shock?
INCREASE
-SVR
DECREASE
- CI
- PCWP
What type of hemodynamic changes would you see with cardiogenic shock?
INCREASE
- PCWP
- SVR
DECREASE
-CI
T/F: The end result of CHF could be ischemic heart disease and hypertension.
TRUE
With congestive heart failure at the inter cellular level there would be __________ intracellular cAMP, ______ of beta receptors and _____ ______ between beta receptors and adenyl cyclase.
- Decreased
- downregulation
- impaired coupling
Hemodynamically what does congestive heart failure respond to:
- decrease preload
- decrease afterload
- improved contraction
Risk factors for low cardiac output syndrome would be:
- DM
- increased age
- female
- preop decreased LVEF
- Increased duration of CPB
What is the pathophysiology of Low cardiac output syndrome (LCOS):
-stunned heart causing hypocontractility due to ischemia and reperfusion
T/F: With low cardiac output syndrome there is up regulation of beta receptors.
FALSE (…..there is down regulation of ….)
What is the line of treatment for low cardiac syndrome:
-positive inotropes
What is the goal in low cardiac output syndrome:
INCREASE
- O2 delivery (SvO2 >70%)
- O2 consumption (arterial blood lactate level =< 2mmoL)
Positive inotropes that are cAMP dependent are:
- beta agonist
- Dopaminergic agonists
- Phosphodiesterase inhibitors
Positive inotrope that are cAMP indepent are:
- cardiac glycosides
- calcium
What are the hemodynamic effects of positive inotropes:
- increased SV
- decrease in LVEDP
Positive inotropes that are considered “PURE” beta 1 agonist are:
- doBUTAMINE
- isoproterenol
Positive inotropes that are considered mixed alpha and beta agonists are:
- Noriepinepherine
- Epinepherine
- doPAMINE
Positive inotropes that are “PURE” beta 1 agonists would be a inodilator or inoconstrictor:
Inodilator
Positive intropes that are mixed alpha and beta agonist would be a inodilator or inoconstrictor:
Inoconstrictor
Positive inotropes ion a failing circulation, effects of inotropes are likely to be more _________.
-pronounced
T/F: Isoproterenol (DA and dobutamine) will worsen tachyarrhythmias.
TRUE
T/F: High doese of noriepinephine and epinephrine for prolonged periods with persistent low cardiac output will increase perfusion to many tissue beds and contribute to renal failure
FALSE (…output will decrease perfusion…)
T/F: Digoxin should be used cautiously in patient with hypokalemia, reanl failure, and bradycardia.
TRUE
What are the arrhythmogenic postential for postive inotropes for medication such as dobutamine, epinephrine, isoproterenol, and DA.
Dobutamine< DA<isoproterenol
What are the steps at the cellular level to make beta agonist work on the cAMP edpendent positive inotrope?
- Catecholamine bind to beta receptors and activate a membrane-bound guanine nucleotide binding protein
- This activate adenyl cyclase and generates cAMP
- cAMP increases Ca influx via slow channels and increases Ca sensitivity of Ca-regulatory proteins.
- Increase the force of contraction and velocity of contraction and velocity of relaxation
Epinephrine works on what receptors and is an agonist or antagonist:
- Alpha 1
- Alpha 2
- Beta 1
- Beta 2
Low doses of epinephrine (1-2 mcg/min) will do what with receptors and body:
- Stimulate (less) Alpha 1 receptors in skin,mucosa,hepatorenal sytem
- Stimulate (MORE) BETA 2 receptor in skeletal system which will decrease SVR and distribute blood to skeletal system
Will MAP stay the same at low does epinephrine:
YES
Intermediate does of epinephrine (4 mcg/min) will do what:
- WORKS MORE ON BETA 1 RECEPTORS
- inotropes
- Increase HR
- Increase contractility
- Increase C.O.
At low dose epinephrine will work as a vasodilator.
TRUE
At high dose epinephrine will work as a vasoconstrictor.
TRUE
T/F: Epinephrine is the least potent activator of the Alpha 1 receptors.
FALSE (..the most potent…)
High dose of epinephrine w(> 10 mcg/min) will do what:
-Works most on the ALPHA 1 RECEPTOR
-constict at the cutaneous, splanchnic, and renal vascular beds
-maintain myocardial and cerebral perfusion
-Increase aortic DBP
-
What type of reflex can epinephrine cause:
BRADYCARDIA
Norepinephrine primary job works on what receptors. What receptors are most effected?
- Alpha 1 agonist (MOST)
- Beta 1 agonist (overshadowed by alpha 1)
- Beta 2 least effected
At low doses norepinephrine will cause and ____ with cardiac output, but at high doses norepinephrine will cause _____ with cardiac output.
- increase
- decrease
Why does norepinephrine cause a decrease with CO at high doses.
- increased afterload
- baroreceptor mediated reflex bradycardia
Which causes a greater cardiac output effect epinephrine or noriepinephrine.
Epinephrine
What receptor would noriepinephrine work on primarily when phentolamine is used in conjunction:
-Beta 1 agonist
Isoproterenol works on what receptors:
- Beta 1
- Beta 2
T/F: Isoproterenol can work as a bronchodilator.
TRUE
The net effect hemodynamically of isoproterenol causes:
- increase in C.O.
- Decrease M.A.P.
What are the uses of isoproterenal:
- chemical pacemaker after a heart transplant or complete heart block
- bronchospasm management during anesthesia
- Used to attempt to decrease PVR in patient with pumonary hypertension and RV failure
DoBUTAMINE works on what receptor:
- Beta 1 (MORE)
- Beta 2 (less)
- Alpha 1 (less)
T/F: Dobutamine has a small percent of dopaminergic receptor activation.
FALSE (Dobutamine has no dopaminergic…)
How does dobutamine increase renal blood flow:
-increase C.O.
Is dobutamine effective in patient who need increased SVR to increase BP.
NO
What would happen to dobutamine if prepared in an alkaline IV solution.
Dobutamine would be inactivated.
Dopaminergic agonist D1 process is:
- G coupled
- stimulate adenylate cyclase
- activate cAMP
Dopaminergic agonist D1 works on:
- Smooth muscle of blood vessles: vasodilation
- Naturesis
- Diuresis
Dopaminergic agonist D2 process is:
- G coupled
- inhibits adenylate cyclase
- inhibits cAMP
Dopaminergic agonist D2 works on:
- Presynaptic: inhibits NE release and promote vasodilation
- Attenuate the beneficial effects of DA on renal blood flow
Dopamine dose at 0.5-3 mcg/kg/min effects:
- DA1
- DA2
Dopamine dose at 3-10mcg/kg/min effects:
-beta effect
Dompamine dose at 10-20mcg/kg/min effects:
-beta and alpha effect
Dopamine dose over 20 mcg/kg/min effects:
-Alpha effects
T/F: Dopamine in low doses is renal protective.
FALSE
T/F: Dopamine in low dose inhibits aldosterone secretion.
TRUE
Dopamine ___ the respitory drive.
blunts
Dopamine _____ splanchnic oxygenation and impairs GI function.
-worsens
How long until tolerance of dopamine on renal effects develope.
-2-48 hours
What neurohormonal effects does dopamine have that are detrimental:
- suppresses endocrine system
- immunosupression
How much dopamine is needed to cause a noriepinephrine release:
over 5 mch/kg/min
A dose of Dopamine (2-10 mcg/kg/min) causes what:
- increase contractility
- increase C.O.
- no change in HR or BP
- ALPHA activation starting
High doses of dopamine ______ release of insulin causing ______.
- inhibit
- Hyperglycemia
Clinical situation dopamine is used in is:
- decreased CO
- Decreased systemic B.P.
- Increased L.V. end diastolic pressure
Dopexamine is a inodilator or inoconstrictor.
Inodilator
What receptor does dopexamine work on:
- Beta 2
- DA 1 receptor
Dopexamine _____ presynaptic reuptake of noriepinephrine.
inhibits
Dopexamine is a (indirect/direct) inotropic activity.
-indirect
Tachycardia is more prevalent in dopamine or dopexamine.
-Dopexamine
What is the use of Dopexamine?
-treat CHF when SVR is high
What are some phosphodiesterase III inhibitors.
- Inamrinone
- milrinone
How does phosphodiesterase III inhibitors work:
- Slow the metabolism of cAMP to 5’-AMP increasing intracellular cAMP concentrations
- increase the Ca sensitivity of contractile proteins
- Increase Ca influx
- Antagonize adenosine
Inamrinone _____ intrapulmonary shunting and ____ PaO2.
- increases
- decreases
T/F: Inamine is more effective with fewer complications than dobutamine during separation from CABG.
TRUE
Inamrines is dose dependent _____ in SV and CI and _____ in SVR and PVR after CABG.
- increases
- Decreases
What are adverse reaction of inamines?
- thrombocytopenia (10%)
- elevated LFT
- Arrhythmias
- Do NOT administer to patient with AORTIC STENOSIS
- May aggravate outlet obstruction in patient with IHSS
Milrinone has _____ inotropic and vasodilator properties to inamrines but ______ times more potent, with a shorter t1/2 and without the risk of __________
- similar
- 15 to 20
- thrombocytopenia
What are the side effect of milrinone?
- HA
- Hypotension
- syncope
- ventricular arrhythmias
- increased ventricular response rate in A. FIB/FLUTTER
What receptor does glucagon work at?
-Glucagon receptor
What hemodynamic effects does glucagon have?
- INCREASE
- CI
- HR
- BP
DECREASE
- SVR
- LVEDP
What are the side effects of glucagon:
- EXPENSE
- N/V
INCREASE
- blood sugar
- coronary resistance
- pulmonary resistance
- vascular resistance
Digoxin is a cardiac _____.
-glycoside
Digoxin has what effect on inotrope, dromotrope, chronotrope.
- positive (Inotrope)
- negative (Negative)
- negative (Negative)
How does digoxin work:
-inhibits Na K-ATPase pump increasing intracellular Na and indirectly intracellular CA
What kind of level would you see in K if Digoxin level were high?
-low K
What are the presentation of digoxin toxicity:
- Anorexia, N/V
- PVC
- Paroxysmal atrial tachycardia with block
- mobitz type 2 AV block
- V. Fib
What is the early presentation of digoxin toxicity?
- anorexia
- N/V
What is the most common dysrrhythmia for digoxin toxicity?
-Paroxysmal atrial tachycardia with block
What is the most frequent cause of death for digoxin toxicity?
-V. FIB
How do you correct digoxin toxicity?
- correct electrolyte balance
- administer phenytoin
- administer lidocaine
- atropine
- beta blocker may be used to suppress increased automaticity
- temporary pacing if complete heart block is present
What does digiband do:
-fab antibody fragment bind to the drug and dcrease plasma consentration of cardiac glycosides
What eliminate the fab antibody:
kidneys
T/F: Ca can inhibit beta agonists by direct inhibition of adenyl cyclase.
TRUE
What do inotropes often cause for low C.O.?
-tachycardia