Test 2 content Flashcards
Negative effects of angiotensin on kidneys
Increased glomerular pressure and fibrosis
Protein leak
Increased Na reabsorption
-ACE-I use benefits HF patients, prevents the following so failing heart doesn’t haven’t to work hard:
- angiotensin increased in HF since low CO
- baroreceptors send signals to kidneys or blood vessels to increase blood volume/flow
- preload increases
- NE released
- endothelin-modifies blood vessels to constrict
Negative effects of angiotensin on heart, primarily what side?
LV
Esmolol MOA and Dosing
MOA: Agent is cardioselective B-adrenergic blocker
Dose: 500mcg/kg over 1min then 50mcg/kg/min with max 300mcg/kg/min (titrate every 5 min)
Esmolol has very short duration of action which is commonly desired in ICU
Lack of intrinsic sympathomimetic and membrane-stabilizing activity
KEY: If desired effect not observed bolus administration repeated before infusion rate is increased
Esmolol vs Labetalol Effect on Myocardial oxygen
Increased
Esmolol vs Labetalol onset of drugs?
Rapid
Labetalol has about____ the active B effects as propranolol
1/5
Esmolol vs Labetalol Duration of Effect HR
Esmolol: Rapid
Labetalol: Slower
PANS is _____activity.
Cholinergic
Beta-blocker comparision esmolol vs labetalol
Onset-Rapid for both
Duration of effect HR-
Esmolol (Rapid) Labetalol (slower)
a-adrenergic blockers
Vasodilator activity on the peripheral vasculature
Side effects -
o-Orthostatic hypotension (hypotension (blood pressure drop from sitting to standing is too much for patient’s body to compensate for and pt can have syncope)
o- Reflex tachycardia - compensate for severe drop in B- this drop can be sensed by brain and drive sympathetic response
Spironolactone is specifically an _____ ______ and is the ______ ______ ______.
aldosterone antagonist
Most common one
SANS is ______ with alpha, B receptors
Adrengeric (EPI NE)
HTN is high ____. This causes ____ in the vasculature. The goal is to _____ the vasculature.
BP
constriction
dilate
Beta blockers can be helpful because they can decrease
Renin
Esmolol Absorption, Metabolism, and Excretion:
- Onset of action is seconds and duration of action up to 10-20 min after cessation
- Metabolism occurs in erythrocytes by esterases and has metabolite (1/500 activity) eliminated in urine
- Do not need to adjust in hepatic or renal failure
- Useful in patients with acute myocardial infarction
Central factors in HTN? 4 physiologic causes of HTN?
1) adrenergic drive = Increased HR & CO
2) High aldosterone - Increased Na+ and Ca2+ -> increased SVR
3) Low renin: Increased Na+ and Ca2+ -> increased SVR
4) High renin -> increased AII -> increased SVR
Postoperative HTN Requires rapid control of BP (3 things)
Control bleeding at suture sites
Neurology checks (patient used to x BP, now receiving y)
Myocardial ischemia develops due to increased oxygen needs
Low BP → ↓ PANS → ↑ HR ↑ SANS → ↑ CO ↑ SVR goal or end result?
Increase BP
Hydralazine on HTN
- Initially slower onset of 5-15min then precipitous fall in BP lasting up to 12 hours
- Circulating half-life is about 3 hours, however effect on BP can last up to 100 hours
- Agent has unpredictable effects on BP and is difficult to titrate
Labetalol Absorption, Metabolism, Excretion
- Onset of action is 5-15min and lasts up to 2-12 hours after cessation
- Extensive first pass metabolism therefore oral form is only about 20-40% bioavailable
- Minute amount of unchanged drug excreted in urine
- Bolus doses of 1-2mg/kg have produced precipitous drops in BP
Esmolol vs Labetalol Effect on SVR
Esmolol: None
Labetalol: decreased SVR
Labetalol MOA & Dosing
MOA: Agent is a selective alpha and non-selective B-adrenergic receptor blocker with a to B ratio of 1:7
Dose: 20mg bolus then 1-2mg/min with max 5mg/min
a-Receptor blocking is responsible for vasodilation of arterial smooth muscle and B-blocking effects the smooth muscle as well as sympathetic stimulation
5 classes of treatment for HTN.
vasodilators:
- Calcium Channel Blockers
- Nitrovasodilators
- Dopamine agonists
- ACE inhibitors
Affect CO
- Beta-Blockers (especially selective ones)
barorecptors sense changes in pressure and flow to _____. Baroreceptors also sense ____ rises and drops (ex: due to dehydration)- baroreceptors can also cause signal to
brain
acute
increase blood volume
Catecholamines can increase HR and cause .
Vasoconstriction
BP Tracing- Pulse Pressure
(SBP-DBP)
- HR
- BP
ACE inhibitors and AT-1 blockers cause ____ in SVR by?
decrease
reducing Angiotensin II
Etiology of HTN perioperative
Vasoconstriction (catacholamines/baroreceptor) combined with intravascular hypovolemia
Angiotensin inhibition for HTN 3 ways to inhibit angiotension:
ACEi
ARB
Parasympathetic stimulation
Postoperative HTN Generally lasts about _____ Higher association with _____
2 to 6 hours
ICU admissions and mortality
Nicardipine Absorption, Metabolism, and Excretion:
- Onset of action is with 1-5 min and duration of action is 2-6 hours after cessation
- Agent is about >95% bound
- Metabolism occurs through CYP 3A4 system substrate therefore monitor for potential drug interactions
- Cardiac sparing effect, therefore no contractility suppression
Rapid changes in peripheral circulation (ie high or low) are addressed via
signal transmission to CNS
Baroreceptors provide the CNS with information regarding BP changes. Most common place is
Carotid arteries
High BP → ↑PANS → ↓ HR ↓ SANS → ↓ CO ↓ SVR goal or end result?
decrease BP
Low blood volume- sends message to kidney to
cause water retention through ADH (but the kidney mechanisms take longer than that of catecholamines)
Nitroglycerin on HTN
- Only effective at higher doses
- Concern for hypotension and tachycardia
- Compromised cerebral and renal perfusion due to preload and caridac output
- Difficult agent to titrate (often given as bolus instead of continuously)
- vasodilator
- Useful in ACS
objectives of Anti-HTN
▪ Overview of therapeutic targets for HTN management
▪ Describe the CV benefits of HTN control
▪ Describe the mechanism of action of each drug class for the management of HTN
▪ Describe the mechanism of action of intravenous therapies used to manage acute HTN
Indications of ACE-I therapy:
HTN -Lower BP
HF - Management of hypertrophy
Post-MI - Prevent additional hypertrophy
DM - Prevention of nephropathy (serum creatinine reflects kidney function, which declines -protein leaks into urine)
Aldosterone normally causes _____
sodium retention
-drugs will prevent that by maintaining sodium within tubule which water follows leading to decreased tension/volume overload
Aldosterone has what physiological effects?
- Increases Na retention -> Water retention
- Increased vascular hypertrophy
- Ability to mediate cardiac injury
- Decreases release of NE
- Monitor serum K for patients on aldosterone antagonist therapy*****
Class 3: Amiodarone Toxicity effects
Pulmonary fibrosis
Photodermatitis:
Corneal microdeposits:
Hepatic: necrosis and failure (IV and oral)
Thyroid dysfunction (hyperthyroidism/ hypothyroidism )
Esmolol vs Labetalol Duration of Effect HR
Esmolol: Rapid
Labetalol: Slower
Anti-Arrythmia objectives
▪ Overview of the classifications for antiarrhythmic agents
Describe the mechanism of action of each drug class for the management of arrhythmias
Describe the unique side effects from Amiodarone therapy
Describe the goals of therapy for antiarrhythmics
Therapeutic targets for HTN
- Aldo blockers
- Diuretics
- Catecholamine inhibitors
- vasodilators
- ARBs
- ACE-i
What are the two classes for rate control? Rhythm control?
Rate: Classes 2 and 4 (BBs and CCBs)
Rhythm: Classes 1 and 3 (Na channel blockers and Potassium channel blockers)
Low BP → ↓ PANS → ↑ HR ↑ SANS → ↑ CO ↑ SVR goal or end result?
increase BP
which non-DHP is more cardioselective for AA:
diltiazem Not as cardioselective as verapamil
MOAs of Beta Blocker AAs
Prevents activation of ß receptors
Decrease the phase 4 slope of pacemaker
↓SA node activation and AV node conduction
By blocking beta receptors, it can decrease the slope of the face takes more time to reach to potential
Perioperative HTN: Systolic BP (SBP) is what?
SBP 20% >perioperative reading >15min, or increase of >50% original value
Incidence is almost 50% depending on the surgery
abnormal systole and diastole
blood pools and goes to brain and clots
AA Suppression of IKr drugs? what class? These drugs can be ____-arrythmia
class 3
can be pro-arrythmia
Ibutilide -However a higher rate of conversion for atrial fibrillation or flutter
Sotalol -QT interval increases of 25-80 msec, dosage dependent
Dofetilide -Initiation of therapy via pharmaceutical monitored program
Acute AP drop: send message to ANS and causes
endogenous catecholamine production and release (EPI and NE) and in the kidneys
Clinical benefits of HTN management
- Decreased pressure on the aortic arch
- Improvements in patients with Sleep Apnea
- Reduced incidence of Stroke
-Improved kidney function
Longevity (High blood pressure is detrimental to kidney function)
What are the 2 most common segments of the EKG?
ST segment
QT interval
Rapid changes in peripheral circulation (ie high or low) are addressed via
signal transmission to CNS
Esmolol vs Labetalol Effect on SVR
Esmolol: None
Labetalol: decreased SVR
Toxicities of lidocaine?
Hypotension when given in large doses (reduced contractility)
Neurologic (tremor, Nausea, slurred speech, and seizures)
Higher incidence in patients with plasma concentrations greater than 9 mcg/ml
Labetalol MOA & Dosing
MOA: Agent is a selective alpha and non-selective B-adrenergic receptor blocker with a to B ratio of 1:7
Dose: 20mg bolus then 1-2mg/min with max 5mg/min
a-Receptor blocking is responsible for vasodilation of arterial smooth muscle and B-blocking effects the smooth muscle as well as sympathetic stimulation
Amiodarone Complex t1/2?
short term 3-10 days and chronic of several weeks to months
Esmolol MOA and Dosing
MOA: Agent is cardioselective B-adrenergic blocker
Dose: 500mcg/kg over 1min then 50mcg/kg/min with max 300mcg/kg/min (titrate every 5 min)
Esmolol has very short duration of action which is commonly desired in ICU
Lack of intrinsic sympathomimetic and membrane-stabilizing activity
KEY: If desired effect not observed bolus administration repeated before infusion rate is increased
Rate control AA Classes?
2 and 4 (BBs and CCBs)
Vaughan Williams Classification of AAs
Class I: Na channel blockers
Class 2: Beta blockers - excluding sotalol that also has class III effects
Class 3: blockade of IKr (Potassium Channel Blocking)
Class 4: CCB
what kind of treatment do HF patients get for Anti-Arrythmia?
ICD, can shut off
Adenosine Therapeutic use and dosing
Conversion of PSVT or diagnostic for EKG
Dose: 6 mg IVP followed by rapid saline flush - T1/2 in bloodstream is approx 10 sec
Can administer a second dose of 12 mg if needed
provides the driving force for organ perfusion & depends on ____ and ____
Art Pressure (AP)
CO and SVR
Lidocaine is what class AA? When do you use it?
Treatment of ventricular tachycardia & fibrillation when amiodarone is unavailable
Prevention of VF after cardioversion in Acute M
I
Prophylactic use for the prevention of VF after acute MI is NOT recommended → increased mortality
Class 3: Amiodarone is given for how long to a patient?
For life
Esmolol vs Labetalol onset of drugs?
Rapid
Class 4 CCB Therapeutic use:
Acute and chronic Paroxysmal Supraventricular Tachycardia (PSVT)
Rate control for atrial fibrillation
Esmolol vs Labetalol Effect on Myocardial oxygen
Increased
Adenosine is ___ effective in presence of theophylline and caffeine
less effective
Perioperative HTN: Systolic BP (SBP) is what?
SBP 20% >perioperative reading >15min, or increase of >50% original value
Incidence is almost 50% depending on the surgery
Class 4: Ca2+ Channel Blockers MOA
Block slow cardiac Ca-channels
↓ phase 0, ↓ phase IV of (automaticity phase) nodal tissues and enhances ERP
Suppress Ca dependent tissues activation or depolarization - ↓ SA activity & ↓ AV conduction (enhance ERP, more effect)