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)