09 - Autonomic Nervous System II - Adrenergic Agonists

Question 0

The balance of adrenergic agonist activity can _____ at different doses

Answer 0

Shift

Question 1

Adrenergic agonists have _____ selectivity/specificity for different adrenergic receptors. The activity can be

Answer 1

Varying

Overlapping

Question 2

Phenylephrine (neosynephrine) is a predominantly

Answer 2

Direct a1 agonist (pure a)

Question 3

The primary effect of phenylephrine is _______. It causes ______ venous return and stroke volume (preload)

Answer 3

Peripheral vasoconstriction

Increased

Question 4

Cardiac output remains the same in most patients given phenylephrine because of

Answer 4

Reflex bradycardia (vagal reflex probably mediated through baroreceptors)

Question 5

Phenylephrine causes _______ coronary blood flow

Answer 5

Increased

Question 6

The vial concentration of phenylephrine?

Answer 6

1% (10 mg/ml)

Question 7

What is the continuous infusion dose for phenylephrine? What can happen at higher doses?

Answer 7

0.25-1 mcg/kg/min (37.5-150 ml/hr)

Decreased renal perfusion at higher doses

Question 8

T or F? Phenylephrine does not have tachyphylaxis.

Answer 8

False, phenylephrine requires upward titration of infusion but it is more common with ephedrine

Question 9

Epinephrine is a ____________ that has variable peripheral effects in

Answer 9

Direct adrenergic agonist

a: skin, mucosa, kidney
b: skeletal muscle

Question 10

Which receptors do epinephrine act on and what effects does it cause?

Answer 10

b1 - increased HR, contractility, and myocardial O2 demand, increased SBP
b2 - bronchodilation, skeletal muscle dilation (decreased DBP?)
a1 - decreased splanchnic/renal blood flow, increased coronary/cerebral blood flow

Question 11

Epinephrine is used to treat?

Answer 11

Anaphylaxis

Ventricular fibrillation

Question 12

Risks of epinephrine?

Answer 12

Cerebral hemorrhage
coronary ischemia
ventricular dysrhythmias

Question 13

What should be used with caution in conjunction with epi? Why?

Answer 13

Volatile anesthetics, especially halothane

Potentiates dysrhythmias

Question 14

What is the dose of epi for vfib?

Answer 14

1 mg = 1 ml of 1:1000

Question 15

What is the dose of epi for anaphylaxis and shock?

Answer 15

50-100 mcg

Question 16

What is the dose of epi for continuous infusion for improved contractility?

Answer 16

.01-.1 mcg/kg/min

Question 17

Which adrenergic agonist can be applied topically or infiltration to decrease bleeding?

Answer 17

Epinephrine - causes vasoconstriction

Question 18

How much epi is added to local anesthetic to prolong block?

Answer 18

1:200,000 - 1:600,000

Question 19

Ephedrine is a ______ with similar effects to

Answer 19

Indirect (and direct) adrenergic agonist

Epinephrine

Question 20

T or F. Ephedrine is a catecholamine that acts on a and b receptors.

Answer 20

False, ephedrine is a NONcatecholamine sympathomimetic

Question 21

How does ephedrine cause tachyphylaxis?

Answer 21

It causes NE release, depleting the stores

Question 22

How long does ephedrine last?

Answer 22

10x longer than epi

Question 23

Ephedrine causes _____ venoconstriction than arteriolar constriction which redistributes _____ and _____ venous return (preload)

Answer 23

More
Centrally
Improves

Question 24

Which adrenergic agonist may have anti emetic properties?

Answer 24

Ephedrine

Question 25

What is the adrenergic agonist of choice in OB?

Answer 25

Ephedrine - thought to preserve uterine blood flow better than direct acting a agonists (evidence is lacking) Phenylephrine - current data supports but consider reflex Brady in setting of sympathectomy

Question 26

What is the dose of ephedrine?

Answer 26

5-10 mg IV

Question 27

Norepinephrine (levophed) is a ______ without

Answer 27

Direct a1 agonist | b2 activity

Question 28

Norepinephrine causes ______ BP due to intense arterial and venous

Answer 28

Increased | Vasoconstriction

Question 29

Does norepinephrine cause reflex bradycardia?

Answer 29

Possible

Question 30

Why isn't norepinephrine a good first line treatment for cardio genic shock?

Answer 30

It causes decreased renal perfusion and increased myocardial O2 requirements Ensure the pt has adequate volume resuscitation Can see end organ ischemia/necrosis Pulmonary vasoconstriction

Question 31

What is the norepinephrine infusion dose and how is it administered?

Answer 31

.01-.1 mcg/kg/min | Central access only (extravasation->tissue necrosis)

Question 32

Which adrenergic agonist is a dose related agonist to all adrenergic receptors?

Answer 32

Dopamine

Question 33

The low dose of dopamine is _____ and stimulates ______

Answer 33

<2 mcg/kg/min | DA receptor

Question 34

_________ of dopamine is considered outdated

Answer 34

Neal dose

Question 35

The low does of dopamine causes

Answer 35

Renal vasodilation, diuresis | Inhibits renal/splanchnic NE release

Question 36

The medium dose of dopamine is ______ and stimulates the

Answer 36

2-10 mcg/kg/min | b1 receptor

Question 37

The medium dose of dopamine causes

Answer 37

Increased contractility, HR, CO | Myocardial O2 demand > O2 supply

Question 38

High dose of dopamine is _____ and stimulates

Answer 38

10-20 mcg/kg/min | a1 receptor

Question 39

What does of dopamine causes risk for dysrhythmias?

Answer 39

High

Question 40

High doses of dopamine cause

Answer 40

Increased PVR, decreased renal perfusion Coronary/pulm vasoconstriction Increased PA pressures

Question 41

Isoproterenol is a highly potent _______ with no

Answer 41

b1 and b2 agonist | No a activity

Question 42

Isoproterenol was used as an ______ because it _______ HR and contractility

Answer 42

Inotrope Increases Risk for arrhythmia Has been replaced by b1 specific agonist (dobutamine)

Question 43

Used to increase HR in presence of a heart block until a place maker can be placed

Answer 43

Dobutamine

Question 44

Which adrenergic agonists increase myocardial O2 demand?

Answer 44

``` Epinephrine Norepinephrine Dopamine (medium dose) Isoproterenol Dobutamine ```

Question 45

Isoproterenol causes _______ which can lead to coronary steal

Answer 45

Coronary artery dilation

Question 46

Isoproterenol was used as a _____ but has been replaced by b2 specific agonists

Answer 46

Bronchodilator

Question 47

Used for bronchodilation and as an inotrope but has been replaced by more selective agonists

Answer 47

Isoproterenol

Question 48

Isoproterenol decreases _____ due to peripheral vasodilation. The overall effect is increased ___ and decreased

Answer 48

SVR SBP DBP

Question 49

Dobutamine is a _____ that increases CO due to contractility. It is also a weak

Answer 49

Selective b1 agonist INOTROPE Coronary vasodilation

Question 50

Dobutamine has ____ b2 activity

Answer 50

Selective Slightly increased and Potential arrhythmias, esp at higher doses Some pulmonary vasodilation Systemic vasodilation -> decreased SVR (hypotension)

Question 51

Dobutamine has some ____ activity that is unmasked when _____ leading to

Answer 51

a1 Beta blocker is given Hypertension

Question 52

What dose of dobutamine potentially causes arrhythmias?

Answer 52

>10 mcg/kg/min

Question 53

Dose of dobutamine?

Answer 53

2-20 mcg/kg/min

Question 54

Fast onset and short acting adrenergic agonist?

Answer 54

Dobutamine

Question 55

This adrenergic agonist is a selective phosphodiesterase (PDE) inhibitor

Answer 55

Milrinone (primacor)

Question 56

How do PDE inhibitors facilitate the inward movement of calcium?

Answer 56

Inhibit PDE III -> increased myocardial cAMP, leading to influx of calcium

Question 57

Which adrenergic agonist is an inodilator?

Answer 57

Mirinone Positive inotropic effect + vascular/airway smooth muscle relaxation + pulmonary vasodilator

Question 58

Milrinone has a ______ effect on SVR

Answer 58

Significant | Leads to hypotension

Question 59

Dose of Milrinone

Answer 59

50 mcg/kg over ten min followed by .5 mcg/kg/min infusion

Question 60

What is the onset of milrinone?

Answer 60

5-15 min Slower onset and offset

Question 61

What is the elimination half time of milrinone?

Answer 61

2.7 hr

Question 62

Which adrenergic agonist should be used with caution in severe renal disease?

Answer 62

Milrinone

Question 63

Clonidine is used to treat ______ because it is a

Answer 63

Hypertension Selective a2 agonist (a2:a1 = 220:1)

Question 64

Clonidine is not commonly administered by

Answer 64

IV Administered PO, TD patch, IM

Question 65

Side effects of clonidine

Answer 65

Brady Hypotension Dry mouth

Question 66

Used as an adjunct for analgesia: added to local anesthetic or opioids for epidural/spinal/nerve block

Answer 66

Clonidine

Question 67

Effective against post operative shivering? Dose?

Answer 67

Clonidine .5-1 mcg/kg

Question 68

Used as a sedative. What are the effects?

Answer 68

Clonidine Anxiolytics, sedation, decreases MAC

Question 69

Highly selective a2 agonist?

Answer 69

Dexmedetomidine

Question 70

ADH is secreted from the

Answer 70

Pituitary gland

Question 71

Non adrenergic sympathomimetic that activates smooth muscle V1 receptors

Answer 71

Vasopressin

Question 72

Vasopressin is an _____ version of ADH

Answer 72

Exogenous

Question 73

Used in the treatment of diabetes insipidus

Answer 73

Vasopressin Because pt with DI lack ADH secretion

Question 74

How is vasopressin used to support BP?

Answer 74

Induces re absorption of water from renal collecting ducts | Vasoconstriction

Question 75

Ackles dose of vasopressin

Answer 75

40 units

Question 76

Lactic acidosis may develop from use of

Answer 76

Vasopressin

Question 77

Which adrenergic agonists have potential to cause arrhythmias?

Answer 77

Epinephrine, especially with halothane High doses of dopamine Dobutamine, more liekly with higher dose Isoproterenol