Nagelhout CV Pharmacology - Final Flashcards

1
Q

Cardiac pharm can be summarized by the treatment of which 4 conditions?

A

-arrhythmias
-HTN
-Angina
-HF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Clinical predictors of increased periop CV risk:
-major risk factors

A

-Unstable coronary syndrome (recent MI or unstable or sever angina)
-Decomp HF (Class IV)
-Significant arrhythmias (symptomatic)
-severe valve disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Clinical predictors of increased periop CV risk:
-intermediate risk factors

A

-mild angina (class I-II)
-previous MI (Q waves)
-comp HF
-IDDM
-Renal insufficiency (Crt > 2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Clinical predictors of increased periop CV risk:
-minor risk factors

A

-old age
-abnormal EKG (LVH, LBBB)
-rhythm other than NSR (Afib)
-low functional capacity (<4 METS)
-hx CVA
-uncontrolled systemic HTN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Surgical case risk factors for periop cardiac events
-High Risk (>5%)

A

-major vasc surgery
-emergent major operations
-prolonged cases with large fluid shift or blood loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Surgical case risk factors for periop cardiac events
-Intermediate Risk (1-5%)

A

-carotid endarterectomy
-endovasc aortic aneurism
-H+N surgery
-intraperitoneal or intrathoracic
-ortho
-prostate surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Surgical case risk factors for periop cardiac events
-Minor risk (<1%)

A

-superficial cases
-cataract surgery
-breast surgery
-ambulatory surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Periop cardiac risk reduction
-pharmacologic interventions

A

-beta blockers (continue thru DOS, don’t start DOS)
-statins (start asap after surgery, ok to take thru DOS)
-alpha-2 blockers

-NTG NOT EFFECTIVE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Periop cardiac risk reduction
-non-pharm interventions

A

-PCI/CABG mixed results on efficacy for periop risk
-monitoring (PAC, CVC, 12 lead EKG, TEE) not shown to effectively prevent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Typically, drugs that depress the heart are _, whereas drugs that stimulate the heart are _

A

anti-arrhythmic (propofol, anesthetics)
arrhythmogenic (pressors)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Path of electricity thru heart:
_ -> _ -> _ _

A

SA -> AV -> Purkinje Fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Antiarrhythmics
-Class I

A

Na channel blockers
-“LA effect on heart”
- depression of depolarization

ex)
IA: Quinidine(IA), Procainamide (IA),
IB: Lidocaine, Phenytoin, Tocainide
IC: Flecainide, Propafenone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Antiarrhythmics
-Class II

A

Beta Blockers

ex) Esmolol, Propranolol, Metoprolol, Timolol, Carvedilol, Nadolol, Acebutolol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Antiarrhythmics
-Class III

A

K Channel Blockers
-prolongs AP and delays repolarization

ex) Amiodarone, Bretylium, Ibutilide, Sotalol, Dofetilide (Tikosyn)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Antiarrhythmics
-Class IV

A

Calcium Channel Blockers
-dominant in AV node

ex) Verapamil, Diltiazem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Antiarrhythmics
-Misc/Class V

A

ex) Adenosine, ATP, Digoxin, Atropine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Increased _ permeability causes depolarization above the atria.

A

calcium
-causes SA and AV node depolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

If pt is having an atrial arrhythmia, treat it with a class _ antiarrhythmic.

A

Class IV (CCB)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Increased _ permeability causes depolarization below the atria.

A

sodium
-causes purkinje depolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

If pt is having a ventricular arrhythmia, treat it with a class _ or class _ antiarrhythmic.

A

Class I or Class III (Na or K Channel blocker)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How do antiarrhythmics that prolong the refractory time help prevent arrhythmias?

A

-bc an arrhythmia can’t fire increased APs when the cell is already in the repolarization phase
-concept of absolute vs. relative refractory period

-Nag used an example of jumping up in the air and coming back down. You can’t jump again while you’re coming back down. It is akin to extending the “coming down from the air” phase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Causes of rhythm disturbances
-General causes

A

-age
-LA dilation
-adrenergic stim
-drug tox
-hypoxia
-hypovolemia
-hemodynamic instability
-reperfusion after CPB
-HTN
-hypo or hyper glycemia
-pulm disease
-beta blocker withdrawal(upregulation of receptors!)
-too light anesthesia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Causes of arrhythmias
-Structural heart disease causes

A

-CAD
-MI
-CHD
-Cardiomyopathy(CM)
-SSS
-Long QT
-WPWS
-SB
-AVB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Causes of arrhythmias
-Transient Disturbances

A

-stress(metabolic or not), laryngoscopy, hypoxia, hypercarbia, device malfunctions, surgical stim, CVC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

The most common arrhythmia is _

A

A fib
-clotting is a big risk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

1st line goal of treating Afib:

A

rate control THEN rhythm control
-GOAL HR is < 110

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

For chronic rate control for Afib, consider _ first, then _

A

CCB
Beta blocker

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

T/F Avoid CCB in COPD/DMII pts.

A

false, avoid BETA BLOCKERS
-beta blockers stimulate the B2 receptor, can cause bronchoconstriction, vasoconstriction, and drops BG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Which is the preferred rate control medication class for Afib for a pt with systolic dysfunction or CAD?

A

Beta blocker-class II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Which type of medication is used as a last resort in treating Afib if other rate control drugs fail or if you want to try to convert quickly to SR?

A

Antiarrhythmics (Amio)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

T/F We should try to convert chronic Afib pts to SR with meds intraop.

A

false
-don’t do this; leave them unless they’re symptomatic or acutely develop Afib in your care.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

T/F A patient has an arrhythmia that originates in the purkinje system, so giving a CCB or beta blocker would work well.

A

false!
-only give CCB or BB if arrhythmia originates from AV node, won’t work for ventricular arrhythmias

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Best way to urgently convert Afib-RVR:

A

DC cardioversion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Adenosine is an agonist on which receptors?

A

Purinergic receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How are Labetalol and Esmolol the same? How are they different?

A

Same:
Both are beta blockers

Differences:
Labetalol is an alpha blocker causing vasocontraction. Longer DOA 3-6 hrs.

Esmolol has a short duration of action of 5-10 min as a result of rapid hydrolysis in the plasma by non-specific esterase enzymes (RBC esterase). Can cause bronchoconstriction (potentially bronchospasm, care w/ asthmatics)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How early should a pt be started on a beta blocker before surgery?

A

7 days at least

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

T/F heart failure is #1 cause/risk of morbidity in anesthesia

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Why do people experience chest pain

A

-blockage of coronary arteries causes ischemia
-ischemia promotes release bradykinin, and other byproducts that stimulate pain receptors in heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

4 cardinal clinical features of angina

A
  1. character = pressure/heavy/squeezing pain (burning or vague pain in atypical)
  2. site and distribution
  3. provocation
  4. duration = builds rapidly w/in 30 seconds and lasts 5-15 minutes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

T/F if chest pain lasts only 10 minutes, it’s classified as angina and if it is more than 15 mins, it is an MI

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Most heart tissue is salvageable if reperfusion occurs within ____ mins

A

100% within 15 mins

60% within 40 mins

first hour is key

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Most angina drugs work by ________. Why?

A

decreasing cardiac demand because increasing supply is much harder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

3 categories of angina

A
  1. stable = lesion (predictable, progressive, exertional angina, 80%); <15 mins, s/s subside
  2. unstable = combination of 1 & 3, angina from lesion and spasm (15% people) >15 mins, s/s persist despite rest/NTG -> MI
  3. variant = spasm (prinzmetal angina, 5% of people, no lesion)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Exercise induced: stable, unstable, variant

A

stable = yes
unstable = yes
variant = no/rarely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Occurs at rest: stable, unstable, variant

A

stable = no
unstable = yes
variant = yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Night pain: stable, unstable, variant

A

stable = occasionally
unstable = yes
variant = early morning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

T/F many sx of angina are masked by anesthesia

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

ST segment: stable, unstable, variant

A

stable = depressed
unstable = elevated OR depressed
variant = usually elevated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

List some conditions that are detrimental to myocardial oxygen balance
-decrease supply
-increase demand

A

decreased supply = tachycardia, hypotension, coronary artery spasm, hypocapnia, anemia, hypoxic, low 2,3 DPG

increased demand = tachycardia, increased preload, increased afterload (HTN), increased contractility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What is a strong predictor of perioperative ischemia under anesthesia

A

tachycardia (higher than 100 usually)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Keep patient’s heart rate less than ____ in OR for greatest benefit (and during ischemia!)

A

70

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Why are beta blockers prescribed for ischemia when they constrict vessels?

A

They decrease the cardiac demand so much that the constriction is a non issue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Why does nitroglycerin make your chest pain go away

A

dilates veins in legs, blood pools in legs, decrease preload, demand decreases, pain goes away

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

First line therapy for ACUTE angina attack

A

Nitrates! = nitroglycerin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Cornerstone for chronic prophylaxis in angina:

A

beta blockers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Most effective drug class for variant angina (prinzmetal):

A

calcium channel blockers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Useful drugs for patients with CAD/angina AND diabetes or vascular disease

A

ACE inhibitors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Canadian classification of angina

A

I = does not occur w/normal activity but long or strenuous activity

II = slight limitation of ordinary activity, may occur w/walking or climbing stairs, in the cold, etc

III = marked limitation of ordinal physical activity, walking one block or one flight of stairs at normal pace

IV = inability to carry on ANY physical activity without discomfort, **present at rest*

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Contraindications for nitrates

A

significant or symptomatic hypotension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Side effects of nitrates

A

-reduction of blood pressure
-headache
-dizziness
-palpitations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Renin release from the kidneys happens with ____ stimulation

A

beta 1

59
Q

How do calcium channel blockers help with ischemia

A

-decrease oxygen demand + vasodilate coronaries =
increase supply!

60
Q

T/F beta blockers are beneficial for variant angina

A

FALSE

CCB are drugs of choice because beta blockers will vasoconstrict and make spasm worse

61
Q

Herbals that can cause bleeding

A

garlic, ginger, ginkgo

62
Q

Elective noncardiac surgery with high risk of bleeding: how long should you wait for bare metal and drug eluting stent

A

bare metal = 4-6 weeks

drug eluting = 12 months

63
Q

T/F patients should discontinue aspirin 7 days prior to surgery always

A

FALSE

not always !!! Usually only in closed space procedures, like closed eye, cranial or prostate…. otherwise continue

64
Q

Stage A-D of heart failure

A

A = high risk of developing HF (HTN, CAD, DM, family hx of cardiomyopathy)

B = asymptomatic HF/Pre HF (previous MI, LV systolic dysfunction, asymptomatic valve disease)

C = symptomatic HF (SOBand fatigue, reduced exercise tolerance)

D = end stage HF (marked symptoms at rest despite maximal medical therapy)

65
Q

Systolic vs diastolic HF

A

Systolic = LVEF </= 40%

Diastolic = LVEF >/= 50%

66
Q

T/F little evidence to suggest drug treatment improves clinical outcomes in diastolic HF

A

TRUE

67
Q

Why are ACE inhibitors effective in HF

A

they vasodilate

67
Q

All patients with reduced EF should be given _____

A

ACE inhibitor

68
Q

2nd thing patient with stable HF and reduced EF should be put on

A

beta blocker

68
Q

Benefit of carvedilol

A

it vasodilates

69
Q

Addition of aldosterone antagonist or diuretic for which HF patients and why

A

HF class II-IV with LVEF </= 35%

manage edema

70
Q

Digoxin for HF

A

-decreases symptoms (keeps them out of hospital)
-does NOT prolong survival

71
Q

5 ways we can stimulate heart (inotropic stimulation)

A
  1. beta 1 agonism (dopamine, dobutamine)
  2. Na/K ATPase inhibition (digitalis)
  3. increase calcium
  4. PDE III inhibition (milrinone)
  5. glucagon
71
Q

2 things we need to control when HF patients present for surgery

A
  1. myocardial depression
  2. peripheral vasodilation
72
Q

T/F dig levels of 0.7 can be toxic in one patient and therapeutic in another

A

TRUE

73
Q

2 reasons patients will be on dig

A
  1. a fib
  2. heart failure
74
Q

Explain how dig works

A

-blocks Na/K ATPase enzyme
-Na+ ions increase inside cell
-increased Na+ decreases the exchange of Ca++
-more Ca++ helps heart beat harder

75
Q

Dig toxicity is related to ______

A

-potassium

-NEED to look at dig level AND potassium if you’re worried about toxicity

76
Q

S/sx of dig toxicity

A

GI = anorexia N/V/D

Neuro = HA, fatigue, confusion, restless, convulsions, coma

Visual = (key) colored vision, green, purple, yellow, halo vision, flickering lights

Cardiac = ANY known arrhythmia !!!!

77
Q

Normal dig level

A

anything up to 2

78
Q

Half life of dig

A

about 36 hours

79
Q

Dig and anesthesia

A

-you’ll almost NEVER give it. Ever.
-just figure out why they’re on it
-check their dig level (if they had one)
-check their potassium (if they have it)
-see if it’s working

80
Q

If serum K is 2.4 and their dig is 1.9, are they therapeutic or toxic?

A

Probably toxic because potassium is low !!!!

81
Q

T/F patients should hold dig 2 days prior to surgery

A

FALSE

keep taking it up to morning of surgery, no need to stop

82
Q

Antidote to digoxin (life threatening), who gets it and how long do you give it over

A

digibind

someone that took greater than 10mg in adults or 4mg in children

give over 30 min period

83
Q

First line therapy for management of supraventricular tachycardias

A

-ventricular rate control
-NO adenosine… too dangerous under anesthesia
-verapamil, esmolol, other beta blocker

84
Q

T/F if you witness a patient develop a new afib, it’s okay to try to convert them

A

TRUE E

NOT if they come in with chronic afib, could have a clot

84
Q

First line for torsades de pointes

A

IV magnesium sulfate

85
Q

3 categories of patients to caution beta blockers in

A
  1. asthmatics = block beta 2 receptors in lungs will cause bronchoconstriction
  2. diabetics = block beta 2 will cause hypoglycemia
  3. patients with claudication
86
Q

If a drug slows AV conduction velocity, it is contraindicated in patients with _____ and which classes of meds are included in this

A

heart block (Ca channel blockers and beta blockers)

87
Q

Adenosine: class

A

class = IV-like or other

88
Q

Esmolol: class, primary use

A

class = II

primary use = tachycardia

88
Q

Verapamil and diltiazem: class, primary use

A

class = IV

primary use = atrial fib or a flutter

89
Q

Stimulation of purinergic receptors cause:

A

-slowing of SA and AV node conduction

-bronchoconstriction

-dilation of cerebral and coronary vessels

-modulation of neuotransmitter release

90
Q

Stage 1 and 2 hypertension and hypertensive crisis categories

A

stage 1 = SBP 130-139 or DBP 80-89

stage 2 = SBP >/= 140 or DBP >/= 90

crisis = SBP > 180 and/or DBP > 120

91
Q

T/F patients with stage 1 hypertension are always prescribed medications

A

FALSE

only if patient has already had cardiovascular event

91
Q

Difference between hypertensive urgency, emergency, and crisis

A

urgency = SBP >180 or DBP >120 but no associated end organ damage

emergency = SBP >180 or DBP >120 but there is acute end organ damage and immediate action is needed

crisis = encompasses both urgency and emergency and is more reflective of the high degree of BP elevation

92
Q

When do the guidelines recommend starting antihypertensive meds

A

younger than 60 = >140/90

older than 60 = >150/90

CKD or DM @ any age = >140/90

93
Q

5 groups of drugs to treat HTN

A
  1. duretics
  2. Ca channel blockers
  3. Beta blockers
  4. ACE inhibitors
  5. ARBs
93
Q

Lifestyle modifications for HTN

A

-weight reduction
-DASH diet
-low Na+ diet
-exercise
-moderation of ETOH

94
Q

_____ is first line for HTN treatment (which class)

A

diuretics

95
Q

T/F beta blockers are no longer indicated as first line drug for HTN

A

TRUE

96
Q

_____ is first line treatment for HF (which class)

A

ACE inhibitors

96
Q

ACE inhibitors end in ____ and ARBs end in _____

A

“pril” and “sartan”

97
Q

T/F diuretics result in reducing in BP because they make you pee

A

FALSE

we don’t really know…. (probably vasodilation from affecting potassium channels in blood vessels)

98
Q

Which 2 antihypertensive drug classes are contraindicated in pregnancy

A

ACEs and ARBs

99
Q

Describe how RAAS works

A

-catecholamine release stimulates beta 1 receptor in kidneys
-renin turns angiotensinogen into angiotensin I
-angiotensin I –> angiotensin II by angiotensin converting enzyme derived from lungs
-angiotensin II stimulates angiotensin receptors and causes increased thirst, vasoconstriction etc.

100
Q

T/F always start with a lower dose of antiarrhythmics under anesthesia than you would outside the OR

A

TRUE

usually 1/2 dose to start

100
Q

How come ARBs do not cause cough

A

they don’t mess with breakdown of bradykinin, they just bind to angiotensin receptor directly (they are more expensive though)

101
Q

Current recommendations for beta blocker prior to surgery

A
  1. if they are on it prior to, then continue through perioperative period
  2. preop workup shows major cardiac disease, consult cardiology, maybe start beta blocker
  3. pts with cardiac index risk >3, it may be indicated
  4. DO NOT start it the day of surgery
101
Q

When you inhibit angiotensin converting enzyme, you block the breakdown of ______ which will cause the patient to do what? (hint: inadvertent side effect)

A

bradykinin, cough!! (very unpleasant for patient)

102
Q

How do beta blockers make your BP go down

A
  1. cardiac depression
  2. vasomotor depression
  3. blocking renin release in kidneys
103
Q

Alpha blockers as antihypertensives: how do they work and why are they bad

A

-cause vasodilation (opposite of alpha agonists)
-can cause severe orthostatic hypotension
-not good for long term use: lots of side effects

104
Q

What is a direct vasodilator? List the big 3.

A

They work directly on the vessel wall

nitroglycerin, nitroprusside, hydralazine

105
Q

How do nitroglycerin and nitroprusside work

A

-nitric oxide is a vasodilator
-nitro group in nitroglycerin and nitroprusside act in same way that nitric oxide does: directly on vessel wall to vasodilate

106
Q

How does hydralazine work

A

affects potassium channels in blood vessels (opens them)

107
Q

For vasodilating drugs: which ones affect arteries, which veins, and which both

A

arterial = hydralazine (reduces afterload)

venous = nitroglycerin (reduces preload)

both = ALL other vasodilating agents

108
Q

T/F nitroglycerin primarily works by dilating coronary arteries causing reduction of angina

A

FALSE

it dilates VEINS in the the legs, blood pools there, preload is reduced, workload on heart is less = no pain

109
Q

What are nonselective beta blockers

A

-block beta 1 and beta 2
-can get some negative effects from beta 2 blockade, we don’t like
-most common…. standard drugs

110
Q

What is a beta blocker with ISA

A

-beta blocker with intrinsic sympathomimetic activity (some intrinsic beta agonism)

-it doesn’t block as strongly (partial efficacy)

-still get bad effects of beta 2 blockade but not as bad as stronger beta blockers

-better for: asthmatics, peripheral vascular disease, etc

111
Q

What is a beta blocker with MSA

A

-beta blocker with membrane stabilizing activity
-more antiarrhythmic than typical BB
-propanolol

112
Q

What are beta blockers with alpha blocking activity: list 2

A

-just like it sounds

-alpha blocking activity to counteract vasoconstriction caused by beta 2 blockade

labetalol and carvedilol

113
Q

3 effects of blocking beta 2 receptors

A
  1. bronchoconstriction
  2. vasoconstriction
  3. reduced energy/fatigue
114
Q

Labetalol vs esmolol for HTN treatment in OR

A

labetalol = easy to titrate, 5mg at a time, vasoDILATION properties, longer duration of action, better at treating HTN (superior choice)

esmolol = nice because it wears off so quick, not nice because it wears off so quick… it is a vasoCONSTRICTOR, better at treating tachycardia

115
Q

Why is esmolol so short acting

A

rapid hydrolysis by RBC esterases in plasma

115
Q

T/F esmolol is cardioselective

A

TRUE AND FALSE

it is labeled as cardioselective but in practice…. no

116
Q

Metabolism of nitroprussude

A

-by hemoglobin!!!
-turns oxyhemoglobin -> methemoglobin (steals electron)
-makes nitroprusside unstable and it breaks open releasing 5 cyanide ions and 1 nitric oxide
-free cyanide taken to liver and interacts with thiosulfate (vit B12) and rhodanese enzyme forms thiocyanate
-thiocyante is peed out from kidneys

117
Q

Problem with metabolism of nitroprusside

A

-too much = too much free cyanide

-goes into cells and interacts with cytochrome oxidase (CO) - allows cells to use oxygen

-results in hypoxia (because oxygen can’t be used by cells!!!!!)

PINK SKIN because HIGH O2 in VENOUS SYSTEM (can’t be used by cells)

118
Q

How to treat cyanide toxicity

A

-stop infusion of nitroprusside

-100% O2

-mechanical ventilation

-correct metabolic acidosis w/bicarb

-3% sodium nitrite 4-6mg/kg slow IV

-sodium thiosulfate 150-200mg/kg over 15 mins

-consider vit B12

119
Q

What is the cause of rebound hypertension following cessation of nitroprusside

A

RENIN release

120
Q

Best drug to treat hypertension with bradycardia and some considerations

A

Hydralazine

can take up to 10 mins to work…..

give 10mg or 20mg

121
Q

Best drug to treat hypertension with tachycardia

A

Labetalol

122
Q

Clonidine: how does it work and 2 considerations

A

presynaptic alpha 2 agonist = sympathoLYTIC

last resort drug for refractory HTN !!

most POTENT drug to show withdrawal symptoms (rebound HTN)

123
Q

T/F ACEs and ARBs should be d/c before surgery (do not take the morning of)

A

TRUE AND FALSE

conflicting info…. may have refractory hypotension, treat with vasopressin

124
Q

Dose of labetalol (weight based)

A

0.25-0.5mg/kg

2-4mg/min

125
Q

Esmolol weight based dose

A

0.5-1.0mg/kg bolus then 50-300mcg/kg/min

126
Q

Initial infusion rate of nitroprusside

A

0.3-0.5mcg/kg/min

increase by 0.5mcg/kg/min

max of 10mcg/kg/min

127
Q

Weight based dosing of nitroglycerin

A

5-200mcg/min titrate by 5mcg/min every 5 mins

128
Q

Weight based dose for nicardipine

A

5-15mg/hr (start at 5)

titrate by 2.5mg/hr q15-30mins

129
Q

Which antihypertensive is contraindicated in liver failure

A

nicardipine and nitroprusside (also kidney failure)

130
Q

Phentolamine weight based dose

A

1-5mg

repeat 5-15 mins

0.5-1mg/hr continuous infusion

131
Q

what are the 2 ways to treat angina?

A
  1. increase supply of blood to the heart (more difficult to do)
  2. Decrease cardiac demand
132
Q

Angina is caused by

A

imbalance between oxygen supply to the heart and oxygen demand. O2 demand is easier to manipulate than O2 supply

133
Q

Strongest indicator of periop angina:

A

tachycardia
-causes GREATEST amount of demand, decreases supply too!
-GOAL HR <70

134
Q

Number 1 tx of angina (or any degree of CAD) =

A

beta blockers
-vasoconstricts a bit BUT….. DRASTICALLY decreases demand (contractility and HR)

135
Q

Nitrates
-MOA

A

decrease O2 demand via a reduction in PRELOAD and some beneficial redistribution of blood flow

136
Q
A