Exam 3 (cardio and resp) Flashcards
3 naturally occurring catecholamines?
Epinephrine, norepinephrine, and dopamine
2 synthetic sympathomimetic agents?
Phenylephrine and dobutamine
Epinephrine strongly stimulates what two receptors?
B1 and B2
it also does alpha
Epinephrine is used to treat what three events?
Anaphylaxis
Cardiopulmonary resuscitation
Treatment of shock with poor tissue O2 delivery and hypotension are combined (this is b/c of its alpha and beta effects)
in patients unresponsive to indirect-acting agents and in those in whom simultaneous Beta 1 (cardiac stimulation) and Beta 2 receptor stimulation (vasodilation) is desired what sympathomimetic would you want to use?
epinephrine may be useful
As HR, LV stoke work, Stroke Volume and CO increases with Epi use what also increases ?
Myocardial 02 consumption
Epi causes an increase in automaticity of all foci, including those that are ectopic what does this end up meaning?
there is a possibility of arrhythmias
What effects does Epi have by stimulating Beta 2 receptors?
Bronchodilation
Vasodilation
Stabilization of mast cells (resulting in decreasing histamine release)
Concurrent alpha stimulation with Epi use promotes a decrease in what?
bronchial secretions
What occurs at low doses of epi (say 10mcg/min)?
What occurs at increased doses of epi?
At low doses more beta = The peripheral vasculature promotes the redistribution of blood flow to skeletal muscle, thus producing a decrease in SVR
At higher doses more alpha effects= vasoconstriction and increase in SVR
SBP increases, DBP remains relatively unchanged, Pulse Pressure increases
When using Epinephrine what changes when coronary arteries are and are NOT obstructed?
If coronary arteries are not obstructed, autoregulation increases O2 delivery to meet the increase in demand.
If coronary arteries are obstructed O2 delivery may be insufficient to meet demand resulting in myocardial ischemia
Increased alpha effects of epinephrine causes what types of vasoconstriction to occur?
splanchnic
Renal
Dose of Sodium Nitroprusside must exceed what amount to cause cyanide toxicity?
500mcg/kg at infusion rates greater than 2mcg/kg/min
What are the first few things you do when someone on Sodium nitroprusside is suspected to have cyanide toxicity?
Treatment of cyanide toxicity consists of discontinuing the sodium nitroprusside infusion, administering oxygen, and treating metabolic acidosis.
If someone is on an epinephrine drip at a rate of 10mcg/min or less what changes would you expect to see?
increased BG PVC's decreased SVR increasing lactate (transient hyperkalemia at first, followed by decreasing potassium)
EKG reveals irregular rate, atrial tachycardia at 183 on an 18 year old, what medication would you administer to control said patients rate?
A. Verapamil
B. Carvedilol
C. Diltiazem
D. Esmolol
Diltiazem is one of the most common calcium channel blockers used for an antiarrhythmic.
AF associated with WPW syndrome.
In what type of infarction is nitroglycerine contraindicated? How do you know they are having the above infarction?
right ventricular infarction which is indicated by ST elevation in leads II, III, and aVF
name the criteria to exclude nitrates for patient treatment?
Nitrates should be avoided in patients with a blood pressure less than 90 mmHg, a heart rate less than 50 bpm or above 100 bpm, and in patients with right ventricular infarction.
L- type CCB indicated as an IV antihypertensive, highly selective for vascular muscle, rapidly metabolized by nonspecific esterases in the blood, half life is 15 min. Starting dose 1-2 mg/ hr titrated up to 16mg/hr, what drug am I?
Clevidipine
Laboring mother with an epidural just placed is lightheaded and then proceeds to complain of nausea and vomits, what two interventions should you do for this?
Administer rapid fluid bolus
Administer phenylephrine
Why is phenylephrine preferred over ephedrine for a laboring mother with low blood pressure (could be due to epidural) ?
phenylephrine is the recommended treatment for maternal hypotension over ephedrine because “ephedrine produces increases in fetal metabolic rate leading to fetal acidosis due to beta stimulation and phenylephrine does not.
cyanide toxicity from Sodium Nitroprusside can be treated with what prodrug?
Sulfanegen sodium
Patient in severe heart block unresponsive to atropine. Hx of CAD with fatigue and SOB. If isoproterenol is ordered for this patient for refractory heart block what could happen?
Isoproterenolis a high risk medication in pts with history of CAD due to the excessive tachycardia, which can produce myocardial ischemia, and arrhythmia. Giving this medication to a patient with a compromised heart would put the patient at risk for MI .
Should clonidine be continued in the perioperative period, why or why not?
abrupt discontinuation of clonidine can result in rebound hypertension, then resulting in increase catecholamine levels = tachycardia and HTN, thus it should be continued throughout the perioperative period.
If a patient is on Tolcapone and Levodopa what drugs should be decreased (until dose assessment) due to a decrease in metabolism of the drugs by the parkinson’s drugs?
Epinephrine norepinephrine dopamine dobutamine isoproterenol
If a septic patient has already received fluid bolus therapy, what is the next step in order to increase blood pressure?
Norepinephrine infusion
What pressor is known to have poor response at increasing blood pressure if patient has gram negative sepsis?
dopamine
What is vasoplegic syndrome?
What is the solution?
When someone is on an ACE inhibitor and after intubation and or maintance of anesthesia have refractory hypotension.
0.5-1.0 unit bolus of vasopressin followed by an infusion dose of 0.03units / min.
What is Prinzmetal’s angina?
Angina occurring at rest
What class of drugs will you want to administer to someone experiencing coronary artery vasospasm and why?
CCB
CCBs also exert a negative inotropic effect on the heart, which can be beneficial in patients with angina…Cardiac contractility is dependent on the influx of calcium into cardiac cells, and this is slowed by calcium channel blockers”.
“Calcium channel antagonists produce relaxation of vascular smooth muscle, resulting in vasodilation. Systemic vasodilation of both arteries and veins results in decreased preload and afterload…Coronary arteries also are affected, with an increase in coronary blood flow. The CCBs are especially beneficial in the prevention of angina resulting from spasm of the coronary arteries, such as with Prinzmetal’s angina.”
Sodium nitrite 3% at 4mg/kg to 6 mg/kg can be administered over 3 to 5 minutes to promote the production of WHAT so that excess cyanide ions can be bound.
Methemoglobin
Which CCB is a long-standing treatment for treatment of cerebral vasospasm associated with neurologic emergencies such as ruptured aneurisms and neurosurgery?
Nimodipine
What is the number one reason people are taken off of ACEI?
What medication class would a patient be switched to if they had the above reaction?
dry persistent cough (can also cause angioedema but the cough is more common)
switch to an ARB
Name three ARB’s ?
Losartan
olmesartan
valsartan
Why do ACEI cause cough?
build up of bradykinin contributes to the cough
Which blood pressure medication is best to treat a pregnant lady with?
hydralazine IV 2.5-20mg is used for hypertensive episodes in pregnancy
Which medication below causes venodilation with a resultant decrease in preload and lower cardiac filling pressures?
Hydralazine
Phenylephrine
Atropine
Nitroglycerin
Nitroglycerin
What must be present (vital signs wise) before labetalol can be used in the acute management of hypertension?
an adequate HR must be present
A laboring women is induced for C section and her blood pressure is 210/110, you decide to give her labetalol. What other vital sign must be in order for you to give labetalol, and if it is low what must you give also?
HR must be adequate and if it is low then also give with glycopyrrolate 0.2mg
(5mg of labetalol is adequate)
What are the parameters on a sodium nitroprusside drip to stay below the cyanide toxicity threshold?
In general, when more than 500 mcg/kg given faster than 2 mcg/kg/min, cyanide is generated faster than the patient can eliminate it.
If a patient is suspected of having cyanide toxicity due to a sodium nitroprusside drip what is your next step?
stop the drip, and administer Oxygen
What medication that is used to lower blood pressure takes 10-20 min to work, thus be patient because if you re-dose too soon you may get burned?
hydralazine
Common dose is 10mg but exact dose is 0.1-0,2mg/kg
reflex tachycardia is an adverse reaction
COMT inhibitors such as Tolcapone and entacapone used with levadopa or carbidopa therapy can reduce the metabolism of a few drugs and thus will require said drugs dose to be lowered with used with these patients… name the drugs that will need to be lowered in dose?
isoproterenol dobutamine dopamine norepinephrine epinephrine
reduced doses should be started initially until the response can be assessed.
If a patient is on digoxin what medication is contraindicated to be administered and why?
calcium because it may lead to cardiac arrest.
When intracellular calcium levels are already high, the extra dose of digoxin created digoxin toxicity which creates an even more increase in calcium influx further enhances the digoxin toxicity effects. Treating this patient with calcium chloride will increase the risk of other serious arrhythmias and possible cardiac arrest.
The metabolism of which of the following hypotensive agents is most likely to be affected in patients with severe renal disease?
Esmolol
Hydralazine
Nitroglycerin
Nitroprusside
Nitroprusside
Hydralazine is metabolized in the liver and Nitroglycerin is extensively metabolized in the liver. Esmolol is cleared in the plasma and tissues via ester hydrolysis.
Quaternary ammonium structure describes what medication that you use to increase someone’s HR?
glycopyrrolate
which drug produces arterial and venous relaxation?
Sodium Nitroprusside
Nitroglycerin
Hydralazine
Sodium Nitroprusside
Which drug has a greater effect on venous than arterial relaxation?
Sodium Nitroprusside
Nitroglycerin
Hydralazine
Nitroglycerin
Which drug primarily has arterial relaxation?
Sodium Nitroprusside
Nitroglycerin
Hydralazine
Hydralazine
MOA of Sodium Nitroprusside, hydralazine and Nitroglycerine?
all 3 agents is believed to be primarily an induced increase in the concentration of vascular nitric oxide (not confirmed with hydralazine)
What is the onset and duration of sodium nitroprusside?
Onset within seconds
Duration 1-3 minutes (3-5 minutes and 1-10 minutes)
How does Sodium Nitroprusside effect: Preload Afterload Cardiac filling pressures Stroke volume Cardiac output
How does Sodium Nitroprusside effect: Preload: Reduces Afterload: Reduces Cardiac filling pressures: Decreases Stroke volume: Increase Cardiac output: Increase
Using Nitroprusside contributes to a decreased in myocardial O2 consumption by?
decreased Left ventricular volumes and diminished myocardial wall tension.
both contribute to a decrease in myocardial oxygen consumption
What is the starting dose of Sodium Nitroprusside?
0.3 mcg/kg/min titrated up until a response occurs
Infusion rates of WHAT are rarely exceeded when using Sodium Nitroprusside?
3mcg/kg/min
A top infusion rater of 3 mcg/kg/min is rarely exceeded when using Sodium Nitroprusside. However young, normotensive patients may require up to?
5mcg/kg/min
MAXIMUM recommended infusion rate of Sodium Nitroprusside is?
10mcg/kg/min
How is Sodium Nitroprusside Reconstituted (mg mixed with how many ml of D5W first)?
(if you were going to dilute in 250/500/1000 ml of D5W it would provide concentrations of what?)
When should it be discarded?
Reconstitute 50 mg by adding 2—3 ml of D5W injection. Further dilute in 250, 500, or 1000 ml of D5W injection to provide concentrations of 200, 100, or 50 mcg/ml, respectively.
The solution should be discarded after 24 hours.
The chemical structure of sodium nitroprusside contains how many cyanide ions? When are they released?
The chemical structure of sodium nitroprusside contains five cyanide ions, which are released upon metabolism by plasma hemoglobin.
When talking about a sodium nitroprusside infusion: One cyanide ion binds with _________ to form cyanmethemoglobine?
methemoglobin
One cyanide ion binds with methemoglobin to form cyanmethemoglobin, whereas the other 4 cyanide ions undergo rhodanese-catalyzed conversion to __________ in the __________.
thiocyanate in the liver
One cyanide ion binds with methemoglobin to form cyanmethemoglobin, whereas the other 4 cyanide ions undergo rhodanese-catalyzed conversion to thiocyanate in the liver, with the thiocyanate undergoing ___________elimination?
Renal
conversion to thiocyanate requires the cofactor ____? (nitroprusside infusion/cyanide toxicity stuff)
thiosulfate B12
Finally, cyanide toxicity results when ______?
the metabolic pathway is quantitatively overwhelmed.
In general, when more than ____ of sodium nitroprusside is administered faster than __, cyanide is generated faster than the patient can eliminate it.
500mcg/kg
2mcg/kg/min
What are the signs/symptoms of cyanide toxicity with sodium nitroprusside?
metabolic acidosis
increased mixed venous oxygen content
tachycardia
tachyphylaxis
What are the treatments of cyanide toxicity?
Stop the sodium nitroprusside
Administer oxygen
Treat metabolic acidosis
Sodium nitrite 3% at 4-6 mg/kg over 3-5 minutes to promote production of methemoglobin to bind excess cyanide ions.
Sodium thiosulfate at 150-200 mg/kg over 14 min can be administered over 15 minutes and administered every 1 hours as needed
Vitamin B12
Hydroxycobalamin can be effective (man made B12)
Methylene blue at 1-2 mg/kg may be useful
A new prodrug sulfanegen sodium is being tested.
Nitroglycerin has a rapid onset and short duration so it is easily titratable. Nitroglycerin causes a ______ dilation, with an increase in venous capacitance and a resultant _______in preload?
venous dilation
decrease in preload
Nitroglycerin has a rapid onset and short duration so it is easily titratable. Nitroglycerin causes a venous dilation, with an increase in venous capacitance and a resultant decrease in preload. This results in ________ cardiac filling pressures, a _______ of myocardial wall tension and ultimately a _______ in myocardial oxygen requirements?
lowering
lessening
decrease
Nitroglycerin’s primary mechanism of action in the relief of angina is a ______ in preload and cardiac work.
decrease
Using nitroglycerin can cause some of the larger coronary vessels to become dilated with a resultant ________ and _______ in blood flow to ischemic myocardium?
reduction and increase
it also relieves coronary spasms
At higher concentrations of nitroglycerin, ________ dilation also can occur?
arterial vasodilation
IV nitroglycerin has an onset and duration of action of?
Onset 1-2 minutes
Duration 10 minutes
Nitroglycerin is extensively metabolized in the _______ and has a half life of _______
liver
3 minutes
IV nitroglycerin is used for “unloading” of the heart in CHF and MI. Guidelines suggest that IV infusions should be instituted following 3 sublingual doses of 0.4 mg every 5 minutes in patients having an ________ (MI)
ST-segment elevation MI (STEMI)
Nitroglycerin infusions are usually started at _____ and titrated to effectiveness.
10-20 mcg/min
Nitroglycerin can also be used for controlled hypotension but is not as effective as an infusion of ________?
WHY?
sodium nitroprusside
Because nitroglycerin exerts its main effect on venous capacitance, any decrease in blood pressure is more volume dependent when compared with sodium nitroprusside-induced hypotension.
Nitrates should be avoided in patient with:
BP of
HR of
Type of infarction
BP below 90 systolic
HR below 50 or above 100
and right ventricle infarction
Nitroglycerin has the ability to relax the smooth muscle of the biliary tract and provide relief from _______ induced biliary spasm
narcotic (opioid)
Generally nitroglycerin is mixed how?
Generally , 50 mg of nitroglycerin is mixed with 250 ml of D5W
How does acetylcholine produce bronchoconstriction?
Acetylcholine activates the muscarinic (M3) receptor of postganglionic fibers of the PNS to produce bronchoconstriction
What are parenchymal cells (specifically in relation to the lungs)?
It refers to the cells that perform the biological function of the organ – such as lung cells that perform gas exchange = alveoli
The PNS influences the airway in what 3 ways?
Airway caliber (diameter)
Glandular activity
Airway microvascular
Explain the pathophysiology of bronchoconstriction?
Vagus Nerve provides the preganglionic fibers
These preganglionic fibers synapse with postganglionic fibers in the airway parasympathetic ganglia.
Acetylcholine activates the muscarinic (M3) receptor of postganglionic fibers of the PNS to produce bronchoconstriction.
Can anticholinergics provide bronchodilation even in the resting state? If so, why and if not why?
Anticholinergics can provide bronchodilations even in the resting state because the PNS produces a basal level of resting bronchomotor tone.
The SNS plays no direct role in control of the airway tone, however, ___________ receptors (a lot of them) are present on airway smooth muscle cells and cause bronchodilation via _________________
B- adrenergic 2
G mechanism
The ANS influences bronchomotor tone through what system?
Nonadrenergic Noncholinergic System (NANC System)
What are the 2 main inhibitory transmitters thought to be responsible for airway smooth muscle relaxation?
Vasoactive Intestinal peptide (VIP)
Nitric Oxide (NO)
What are the 2 main excitatory transmitters that are shown to cause neurogenic inflammation, including bronchoconstriction?
Substance P (SP)
Neurokinin A (NKA)
What is the mainstay therapy for bronchospasm, wheezing, and airflow obstruction?
Beta adrenergic agonist
Short acting Beta-2 Agonist Therapy is effective for rapid relief of?
wheezing, bronchospasm, and airflow obstruction
Long acting Beta-2 Agonists Therapy are used as maintenance therapy providing what improvements and what does it reduce?
improved lung function
reduction in symptoms and exacerbations
What is the mechanism of action of a short acting Beta-2 agonist?
Bind to the Beta-2 adrenergic receptor located on the plasma membrane of smooth muscle cells, epithelial, endothelial, and many other types of airway cells.
This causes a stimulatory G protein to activate adenylate cyclase which converts adenosine triphosphate (ATP) into cyclic adenosine monophosphate (cAMP) causing smooth muscle relaxation
How does cAMP cause smooth muscle relaxation?
Don’t know?
There are however, decreases in calcium release and alterations in membrane potential … which are the mostly likely mechanisms for smooth muscle relaxation…
What is the MOA of long acting beta 2 agonists?
same as short acting beta 2 agonists
but have unique properties allowing for longer duration of action
what explains the longer duration of salmeterol and formoterol?
Salmeterol has a longer duration because of a side that chain binds to the Beta-2 receptor and prolongs the activation of the receptor.
Formoterol has a lipophilic side chain allowing for interaction with the lipid bilayer of the plasma membrane. This allows a slow and steady release prolonging its duration of action.
what beta 2 agonist has a lipophilic side chain allowing for interaction with the lipid bilayer of the plasma membrane. This allows a slow and steady release prolonging its duration of action?
Formoterol
What beta 2 agonist has a longer duration because of a side that chain binds to the Beta-2 receptor and prolongs the activation of the receptor?
Salmeterol
long acting beta 2 agonist effects are seen in what amount of time?
clinical effects are seen in a matter of minutes (just like short acting)
activation of beta 2 adrenergic receptors in skeletal muscle can produce what side effects?
Tremors
activation of beta 2 adrenergic receptors in vasculature can produce what side effects?
tachycardia
what three metabolic /electrolyte changes can occur with B2 agonist therapy (long or short) but tends to decrease with regular use?
hyperglycemia
hypokalemia
hypomagnesaemia
Tolerance of a beta-2 adrenergic is likely due to?
Beta 2 receptor down regulation
A decrease in duration of bronchodilation and magnitude of side effects would tell you what about a beta 2 agonist.
tolerance has occurred
Withdrawal of a beta-2 agonist after regular use can produce?
transient bronchial hyperresponsiveness (exaggerated bronchial restriction).
Evidence shows an association between using _______Beta-2 agonist therapy without concomitant use of a ___________ with fatal and near-fatal asthma attacks
long acting
steroid inhaler
It is prudent to reserve long acting Beta-2 agonists for those pts who?
are poorly controlled on inhaled steroids alone
or have symptoms perilous enough to warrant the potential added risk.
Which of the following adrenergic agonists can be given IV. Choose ALL that apply: A.) epinephrine B.) albuterol C.) Terbutaline D. ) Salbubtamol
A.) epinephrine B.) albuterol C.) Terbutaline D. ) Salbubtamol ALL
What routes can Terbutaline be given as?
inhaled or nebulized
subq
IV
oral
What routes can albuterol be given as?
inhaled or nebulized
IV
What routes can Epinephrine be given as?
nebulized or inhaled
subq
IV
Inhaled adrenergic agonists act on what receptors to produce bronchodilation?
beta 2
Inhaled anticholinergics act on what receptors to reduce airway tone?
Muscarinic (specifically M1 and M3)
Use of inhaled anticholinergics in _________ as maintenance and rescue therapy is standard treatment.
COPD
Where are the muscarinic 2 (M2) receptors located and what is it responsible for?
Postganglionic cells
limiting production of Ach and protect against bronchoconstriction
Acetylcholine binds to the M3 and M1 receptors and causes smooth muscle contraction. This smooth muscle contraction is produced from increases in cyclic guanosine monophosphate (cGMP) or by activation of a G protein (Gq). Then Gq activates ______________ to produce _________.
Then Gq activates phospholipase C to produce inositol triphosphate (IP3)
Mydriasis is
pupillary dilation
Volatile anesthetics lower the arrhythmogenic threshold for epinephrine
The order of sensitization is ?
halothane enflurane sevo iso des
The hemodynamic changes produced by thiopental are principally caused by ?
decrease in contractility, which results from reduced availability of calcium to the myofibrils and decreased venous return.
Thiopental should be used with caution in patients with?
left or right ventricular failure, cardiac tamponade, or hypovolemia
Dose of thiopental?
2-5mg/kg
Patients who have hypovolemia, cardiac tamponade, or low CO probably represent the population for whom you would want to use which induction medication?
etomidate
One of the most common and successful approaches to blocking ketamine-induced hypertension and tachycardia is ?
prior administration of benzodiazepines
what is probably the safest and most efficacious drug for patients who have decreased blood volumes and cardiac tamponade?
ketamine
All opioids, with the exception of _____, produce bradycardia
meperidine
A major advantage of fentanyl and its analogs for patients undergoing cardiac surgery is their ?
lack of cardiovascular depression (smooth CV induction)
