Quiz 2 Flashcards
1
Q
Perioperative HTN - Primary cause: Increased _________ discharge with systemic vasoconstriction
A
sympathetic
2
Q
Perioperative Hypertension Complications:
A
- CVA
- MI
- ischemia
- LV dysfunction
- arrhythmias
- increased suture tension
- hemorrhage
- pulmonary edema
- cognitive dysfunction
3
Q
Hemodynamic Effects of vasodilators
A
Reflex increase in HR (Baroreceptors) pure
Redistribution of coronary blood flow
- NTG may improve collateral circulation
- Others may cause coronary steal
4
Q
Hydralazine (apresoline)
A
- Direct acting arterial vasodilator
- Inc HR, contractility, renin activity, fluid retention, CO, SV
- Dec BP (diastolic > systolic) and SVR
- Has own receptor referred to as hydralazine receptor – cGMP pathway
5
Q
Avoid hydralazine in patients with?
A
- CAD
- Increased ICP
- Lupus
(Increases myocardial oxygen demand )
6
Q
Hydralazine S/S
A
- paralytic ileus
- Anemia
- aganulocytosis
- muscle cramps
- edema
7
Q
Hydralazine onset
A
30 mins
8
Q
Hydralazine advantages
A
- Maintains/increases cerebral blood flow
- increased CO and SV
9
Q
Nitroglycerine
A
- Causes a release of nitric oxide for non-specific relaxation of the vascular smooth muscle
- Dilates veins > arteries
- Dec PVR, venous return, myocardial oxygen consumption
- Relaxes coronary vessels and relieves spasms
10
Q
Non-cardiac Effects of NTG
A
- Dilates meningeal vessles (caution with inc ICP)
- Dec renal blood flow with dec BP
- Dilates pulmonary vessels
11
Q
NTG onset
A
1 min
12
Q
NTG Metabolism/Tolerance
A
Metabolized by glutathione nitrate reductase in the liver
Nitrite ion oxidizes Hgb to methemoglobin
Tolerance in arterial vessels can occur with chronic administration but not in the venous vessels
13
Q
NTG S/S
A
- Headache (most common)
- Postural hypotension
- Methemoglobinemia
- anaphylaxis
- oral and conjunctival edema
14
Q
NTG Warnings/Contraindications
A
- PDE5 inhibitors viagara, Cialis – profound hypoTN
- Narrow angle glaucoma
- Head trauma, cerebral hemorrhage
- Severe anemia
15
Q
Nitroprusside
A
- Inc cerebral blood flow and ICP
- Renal blood flow: maintained, slight reduction
- Overall reduction in myocardial O2 demand
- With abrupt discontinuation: reflex tachycardia and hypertension
16
Q
odd about kinetics of Nitroprusside
A
Half-life can be as long as 7 days d/t compound build up
17
Q
Nitroprusside S/S
A
- retrosternal discomfort
- thiocyanate/cyanide toxicity
- Increased Cr
18
Q
Nitroprusside Warnings/Contraindications
A
- Congenital optic atrophy
- Hypovolemia
- Compensatory HTN (AV shunting, aortic coarctation)
- Inc ICP
- Severe renal/hepatic impairment
19
Q
Thiocyanate/Cyanide Toxicity S/S
A
- Hypotension
- blurred vision
- fatigue
- metabolic acidosis
- pink skin
- absence of reflexes
- faint heart sounds
20
Q
Thiocyanate/Cyanide Toxicity Increased risk
A
- doses over 4 mcg/kg/min
- > 2 days of therapy
21
Q
Thiocyanate/Cyanide levels
A
Thiocyanate:
- Therapeutic 6-29 mcg/mL
- Fatal: >200 mcg/mL
Cyanide
- Toxic: > 2 mcg/mL
- Fatal: > 3 mcg/mL
22
Q
Treatment of Cyanide Toxicity
A
- Stop infusion
- Administer 100% oxygen
- Correct metabolic acidosis
- Administer 3% sodium nitrite 4-6 mg/kg slowly IV
- Administer sodium thiosulfate 150-200 mg/kg IV over 15 min breaks down cyanide
- Consider Vitamin B12 25 mg/hr
23
Q
Which nonselective alpha antagonist irreversibly binds to the receptor?
A
Phenoxybenzamine
24
Q
Phenoxybenzamine use
A
- Long-term preoperative treatment to control the effects of pheochromocytoma (“chemical sympathectomy”)
- Relieve ischemia in PVD
- BPH to improve flow
25
Phenoxybenzamine
- Reduced PVR to reduced BP
- Secondary increases in NE due to alpha 2 blockade can increase HR and CO
- Crosses the BBB
26
Phentolamine uses
- Hypertension secondary to pheochromocytoma
- Clonidine withdrawal hypertension
- Erectile dysfunction
- Extravasation of catecholamines
27
Oral Alpha 1 Antagonists for BPH
"-osin's"
| Might not give effect you want from giving alpha agonists
28
Alpha 2 Agonists and Cardiac Complications
Reduce cardiac complications: Cochrane Review
- Overall mortality
- Cardiac mortality
- MI
Vascular Surgery especially beneficial
29
Clonidine
- Decreases HR, BP, C.O., and SVR (Baroreceptors reflexes are preserved)
- Abrupt cessation of drug may lead to rebound hypertension (at risk if using for at least 6 days)
30
Why do you get rebound HTN after abrupt cessation of Clonidine? Treatment?
Due to NE upregulation of receptors
Need combined alpha/beta blocker (labetalol/coreg)
31
How long does clonidine patch take?
2 days to reach full potential
32
Clonidine: effects on anesthesia
- Reduces propofol and thiopental requirements
- Alternative to N2O for shortening induction time and attenuating the adrenergic response to intubation during inhaled anesthesia
- Supplement of regional blocks
33
Which has a higher affinity for Alpha 2 receptors, clonidine or Precidex?
Precidex (1620:1 vs 220:1)
34
Dexmedetomidine S/S
-Nausea/vomiting, Fever, Hypoxia
Bolus:
-Hypertension.*
-Bradycardia.
(Clinically significant bradycardia and sinus arrest in young, healthy volunteers with high vagal tone.*)
Infusion:
-Hypotension
35
Look at slide 58
.
36
Methyldopa use
HTN in 3rd trimester
37
Methyldopa S/S
- Fluid retention
- Positive Coombs test
- hemolytic anemia
- bone marrow suppression
- impotence
38
A.C.E. Inhibitors
- Predominantly arterial vasodilators
- Treat CHF and MR by afterload reduction
- Increase CO without excessive decrease in preload
39
ACEs best in _______ pt due to renal protection
diabetic
40
Look at slide 65
.
41
Most end in “-pril”
ACE inhibitors
42
ACE Inhibitors S/S
- Cough, congestion, and rhinorrhea most common side effects
- Angioedema serious side effect
- Safe to DC w/o taper
43
Cough due to increased ________ in the lungs, does not go away unless changing med to ARB or similar
bradykinin
44
A.C.E. Inhibitors caution with
- ARF and hyper K+
| - Do NOT use at all during pregnancy
45
“-sartans”
ARBs (less cough/angioedema than ACEIs)
46
Calcium Channel Blockers effects
- Negative Inotropic effect
- Negative dromotropic effect (AV conduction block)
- Vasodilation of systemic, splanchnic, coronary and pulmonary beds
47
phenylalkylamines
verapamil
48
benzothiazines
diltiazem
49
Dihydropyridines
"-dipines" (pure atrial dilators)
50
verapamil, used for
Potent negative inotrope, dromotrope and vasodilator
Used for:
- Aortic Stenosis and IHSS
- Conversion of atrial re-entry tachyarrhythmias
- Coronary artery vasospasm (Prinzmetal angina
51
Verapamil S/S
- Constipation
| - lower extremity edema
52
Look at slide 89
.
53
CCBs S/S
Arthralgias/joint stiffness, itching
54
Which CCBs better at reducing workload on heart
Verapamil and Diltiazem
55
May potentiate the effects of neuromuscular blocking agents
CCBs
56
_________ reduces gastric emptying
Clevidipine
57
_______ increases sedative effects of midazolam
Diltiazem - increased DOA
58
Beta Blockers actions
- Decrease C.O. (HR and contractility)
| - Decrease renin release
59
Beta blockers advantages over vasodilators
- No reflex tachycardia or widening of pulse pressure
- Improved MvO2 (decrease HR and decrease contractility)
- Intrinsic antiarrhythmic activity
60
Non-selective Beta blockers
Propranolol, Nadolol, Timolol, Pindolol, Carteolol
61
Look at slide 102-103
.
62
BBlockers S/S
Non-selective blockade of Beta-2 receptors
- Vasoconstriction and worsening PVD
- Bronchospasm
Myocardial depression
-Decreased contractility could precipitate CHF
Life-threatening bradycardia or asystole
Hyperkalemia in renal failure*
63
Caution when using with Verapamil, Digoxin. Why?
- Verapamil (decrease HR and contractility)
| - Digoxin (decrease HR and conduction)
64
BBlocker O/D treatment
- Treat with atropine
- May need Isoproterenol, dobutamine and/or glucagon infusion
- Could ultimately need pacing
65
BBlockers contraindications
- Severe bradycardia
- > 1st degree heart block
- Cardiogenic shock
- Raynaud’s disease
Caution
- Asthma/COPD
- Diabetes can cause hyperglycemia or mask hypoglycemia
- Heart failure
66
Labetalol
Combines weak Alpha blockade with weak non-selective Beta blockade
67
BBlocker caution
Do not stop abruptly due to rebound hypertension and tachycardia
Anticholinesterases may increase bradycardia
68
Look at slide 120
.
69
Look at slide 123
.
