Ex3 Vasodilators Flashcards
BP =
COxSVR
CO=
HRxSV
increased BP is a result of
either increase in CO or increase in SVR
Increased CO occurs d/t
SNS: Beta-1 activation in heart
Increased SVR d/t
SNS: Alpha-2 activation
RAAS: increased aldosterone=H2O retention, AngiotensinII activation=vasoconstriction
Goal SBP
BASELINE - if baseline = 180, aim for that
secondary causes of HTN
OSA, pheochromocytoma, hyperparathyroidism
Essential HTN
primary HTN
B1 Blockers will result in
Decreased: HR, CO
Negative chronotropic effects
B1 Blockers = increased CO in which patients?
Rapid Afib
B2 agonist
Bronchodilation
Atenolol
+ B1-selective
NO a1 blockade
Carvedilol
NO B1 selective
+ a1 blockade
Esmolol
+ B1 Selective
NO a1 blockade
Labetalol
NO B1 selective
+ a1 blockade
Metoprolol
+ B1 selective
NO a1 blockade
Propranolol
No B1 selective/a1 blockade
Selective Beta-1 beta blockers
Atenolol
Esmolol
Metoprolol
Non-selective beta blockers
(+a1 blockade)
Carvedilol
Labetalol
Propranolol (-)a1 blockade
Which beta blockers are not beta selective or alpha1 blockers?
Propranolol
Metoprolol PO 2.5mg = ? IV
1mg
Labetolol Beta:Alpha PO
3:1
Labetolol Beta:Alpha IV
7:1
Main reason to use beta blockers
tachyarrhythmias
Beta blockers are condraindicated in
NOT in COPD/asthma - preferable to use B1 selective, but if not just have albuterol on standby
Beta Blocker benefit in periop
decreased risk of post-op MI
prophylaxis for Afib
Beta blockers common adverse effects
hypotension bronchospasm bradycardia/heart block worsening CHF angina pectoris/MI upon abrupt d/c rebound HTN
Selective Alpha1 blockers
prazosin
terazosin
doxazosin
tamsulosin
Non-selective Alpha1 blockers
phenoxybenzamine
phentolamine
Tx pheochromocytoma
non-selective alpha1 blockers
phenoxybenzamine
phentolamine
effect of selective alpha1 blockers
systemic vasodilation
effect of non-selective alpha blockers
decrease both HR/BP
adverse effects of alpha receptor blockers
hypotension
exaggeration of hypotension during epidural anesthesia
Tx of alpha blocker hypotension
phenyl or norepi
Poor mans Dex
clonidine
MOA clonidine
selective partial alpha2 agonist
Adverse effects of Alpha2 agonists
(clonidine) sedation hypotension bradycardia *rebound HTN
ACE-Inhibitors with + active metabolites
Enalapril
Ramipril
Caution with ACEI in OR
Renally eliminated
+ active metabolites in some
Adverse effects - ACEI, ARB
hypotension angioedema ARF hyperK **cough (only ACEI)
Rx intxn -ACEI, ARB
potassium supplements
potassium sparing diuretics
** cautious w/ other hypotensive agents
Contraindicated ACEI, ARB
pregnancy
dihydropyridine CCB
nifedipine
amlodipine
nicardipine
clevidipine
non-dihydropyridine CCB
verapamil
diltiazem
CCB that decreases HR
diltiazem
verapamil
(nondhp)
CCB that increases/doesn’t effect HR
nifedipine
nicardipine
clevidipine
CCB that decreases will HR will also
decrease SA/AV node conduction
CCB that causes coronary artery dilation most
nifedipine
nicardipine
clevidipine
CCB that causes peripheral artery dilation most
nifedipine
nicardipine
clevidipine
Uses for diltiazem/verapamil in OR
IV -
supraventricular tachydysrhythmias
HTN
Use for nifedipine, nicardipine, clevidipine in OR
HTN
Use for nimodipine in OR
cerebral artery vasospasm prophylaxis
CCB anesthetic Rx intxn
additive negative inotropy/peripheral vasodilation
CCB Rx intxn
Dig, BB, amio
increased risk for AV block
Adverse effects DHP CCB
reflex tachycardia
Adverse effects non-DHP CCB
bradycardia–> cardiac arrest
HTN urgency
SBP >/= 180
and/or
DBP >/= 110
w/o evidence of target organ damage
HTN emergency
SBP > 200
and/or
DBP > 120
w/ concurrent target organ dysfunction
HTN emergency organ damage
AKI, liver injury, retinopathy, seizures
High risk HTN emergency
CAD, DM, PVD, impaired renal fxn, smoking, elevated LDL
Overall Tx of HTN emergency
Gradual decrease in BP
HTN emergency in acute aortic dissection
Goal HR <60 BPM
Goal SBP <100-120 mmHg
ASAP (<5-10min)
HTN emergency in ischemic stroke pt
HTN after stroke is bodys way of maintainin CPP
-increased risk for hemorrhagic conversion if given thrombolytics
Goal BP in intracerebral hemorrhage
SBP 140-160
HTN urgency vs HTN emergency treatment
emergency: must come down quicker than urgency
Urgency: discharge onto PO Rx
Nitroprusside effect on preload, afterload, CO
(-)preload
(–)afterload
(+)CO
Fast on/off
Hydralazine effect on preload, afterload, CO
Avoid in OR, unpredictable
(n/a)preload
(-)afterload
(+)CO
Nicardipine effect on preload, afterload, CO
(n/a)preload (-)afterload (+)CO Fast on Slow off
Clevididipine effect on preload, afterload, CO
*same as nicardipine, except fast on AND OFF
(n/a)preload
(-)afterload
(+)CO
Nitroglycerin effect on preload, afterload, CO
(–)preload
(-, n/a)afterload
(+,n/a)CO
Fast on/off
Esmolol effect on preload, afterload, CO
(n/a)preload
(n/a)afterload
(-)CO
Fast on/off
Metoprolol effect on preload, afterload, CO
*same as esmolol –> except longer duration
(n/a)preload
(n/a)afterload
(-)CO
Enalaprilat
discouraged in OR d/t prolonged duration
Phentolamine
quick on/off, DOC pheo, catecholamine induced HTN emergency
Nitroprusside characteristics
- Toxic metabolites w/ renal/liver failure (>72h or >3mcg/kg/min)=avoid
- avoid in neuro d/t increased ICP
Hydralazine characteristics
- OK for pregnant pts
- Lupus like syndrome (w/ long term use)
- avoid in OR d/t prolonged duration
Nicardipine characteristics
- Reflex tachycardia
Clevidipine characteristics
- Lipid (calories/infxn risk)
- caution: egg/soy allergy
- metabolized by plasma esterases (off quick)
Nitroglycerin characteristics
- tachyphylaxis
- flushing, erythema
- dilates veins > arteries
- “vasospasm prophylaxis” after CABG
Esmolol characteristics
- C/I in heart failure
- metabolism via plasma esterases
- aortic dissection = need arterial vasodilator for tachy (i.e. nitroprusside)
Metoprolol, Labetolol characteristics
Contraindicated in heart failure
Avoid which drugs in HF?
Beta Blocker
Preferred Rx in HTN pregnant patient
DOC: Labetolol
2nd: hydralazine
Enalaprilat characteristics
- too long acting for OR
- do not use in pregnant
Fenoldopam characteristics
- pure dopamine agonist
- pure vasodilator =reflex tachy
- hypokalemia (from diuresis)
- avoid in neuro (ICP)
Drugs to avoid in neuro patients
Nitroprusside
Fenoldopam
