Module 7 - Cardiac Pharmacology

Question 0

Medication Access

Answer 0

Drugs typically require 1 to 2 minutes to reach the central circulation when given to peripheral access.

Resuscitation drugs are usually administered by bolus injection, followed by a 20 mL bolus of IV fluid.

The intraosseous (IO) route maybe used if IV access isn’t available, with endotracheal administration being another alternative.

Endotracheal administration results in lower blood concentrations of the same dose given intravascularly

Question 1

Resuscitation

Answer 1

Resuscitation guidelines are evidence – based recommendations. This means that international resuscitation experts meet to evaluate published research and new conclusions in the form of recommendations.

Drugs should be given during CPR as soon as possible after the rhythm is checked. Drug delivery should not interrupt CPR.

Question 2

What are the two categories of ACLS drugs?

Answer 2

Medications for cardiovascular support:
These are sometimes called pharmacology I category drugs; they alter cardiac output, rate, and peripheral vascular resistance.
Medications for arrest rhythms:
These medications control rate and rhythms.

Question 3

Name 10 medications for cardiovascular support (pharmacology I category drugs)

Answer 3

Epinephrine
Vasopressin
Norepinephrine
Dobutamine
Dopamine
Digoxin
Inamrinome
Milrinone
Nitroglycerin
Sodium nitroprusside

Question 4

What are the effects of Epinephrine (pharmacology I category drug) when used for cardiovascular support?

Answer 4

Inotropic/vasopressor

Question 5

What are the effects of Vasopressin (pharmacology I category drug) when used for cardiovascular support?

Answer 5

Non-adrenergic peripheral, coronary, and renal vasoconstrictor

Question 6

What are the effects of Norepinephrine (pharmacology I category drug) when used for cardiovascular support?

Answer 6

Inotrope/vasoconstrictor

Question 7

What are the effects of Dopamine (pharmacology I category drug) when used for cardiovascular support?

Answer 7

Adrenergic agonist/dopamine agonist

Question 8

What are the effects of Dobutamine (pharmacology I category drug) when used for cardiovascular support?

Answer 8

Inotrope

Question 9

What are the effects of Nitroglycerin (pharmacology I category drug) when used for cardiovascular support?

Answer 9

Vasodilator

Question 10

What are the effects of Digoxin (pharmacology I category drug) when used for cardiovascular support?

Answer 10

Inotrope/ventricular rate control
Indications:
digoxin is used in advanced cardiac life support (ACLS) to slow ventricular response in atrial fibrillation or atrial flutter.
Precautions:
Digoxin toxicity is frequently associated with serious arrhythmias.

Question 11

What are the 3 Specific Pharmacology Agents?

Answer 11

Oxygen: provide 100% O2
Key component in resuscitating and emergency cardiac care.
Used for all patients with acute chest pain due to cardiac ischemia, hypoxemia, and cardiac arrest.

Dosage:
You can provide 22% to 100% FIO2 through positive – pressure ventilation or with a manual resuscitator bag.

Precautions:
Problems with oxygen depend on the concentration and the duration of exposure.

Question 12

Describe what epinephrine is and does

Answer 12

Natural Catecholamine (naturally occurs the human body) with both alpha and beta effects.
Causes peripheral vasoconstriction, leading to improved myocardial and cerebral perfusion to vital organs.
Increases BP and the rate and force of contraction.

Question 13

What dosage of epinephrine should be used during a code?

Answer 13

Dosage:
Standard dose is 1 mg given intravenously every 3 to 5 minutes
Precautions:
Should not be mixed with alkaline solutions such as bicarb (HCO3).
If given in patients who are not in cardiac arrest, could result in hypertension.

Question 14

What is Vasopressin?

Answer 14

Vasopressin is a naturally occurring antidiuretic hormone (ADH)
In high doses, it acts as a noradrenergic peripheral, coronary, and renal vasoconstrictor.
Indications:
Vasopressin could be considered as an alternative to either the first or second dose of epinephrine and treatment of pulseless arrest. It may be effective in patients with asystole or pulseless electrical activity and in patients who remain in cardiac arrest after treatment with epinephrine.
Dosage:
Single – dose vasopressin is given one time only has 40 units IV/IO.
Precautions: the current evidence for the use of the suppressant in cardiac arrest is promising, but it’s use hasn’t improved the rate of intact survival to hospital discharge.

Question 15

What is norepinephrine?

Answer 15

Norepinephrine is a potent alpha vasoconstrictor and beta-1 inotrope. Low doses primarily result in inotropic effects, with higher doses producing mixed effects.
Indications:
Norepinephrine is primarily used for severe hemodynamically significant hypotension and low total peripheral vascular resistance refractory to other sympathomimetics.
Dosage: norepinephrine is mixed and infused through a central venous catheter to minimize the risk of extravasation. (If given via IV and it accidentally pops out and drips on skin it will shut down circulation to the entire area)

FYI:
Dosage is 0.5 to 1 µg/minute and titrated to achieve a systolic blood pressure of at least 90 mmHg. The average adult dose is 2 to 12 µg/minute.

Question 16

What is sodium bicarbonate?

Answer 16

Sodium bicarbonate is a buffer (base) that combines with acid (in effect neutralizing the acid).
Sodium bicarbonate is indicated in situations where there has been a bicarbonate – responsive metabolic acidosis prior to arrest, hyperkalemia, or some drug overdoses.
H2O + CO2 ↔️H2CO3 ↔️H + HCO3

Question 17

Why must sodium bicarbonate be used with caution during cardiac arrest?

Answer 17

During cardiac arrest, if CO2 removal is compromised, administration of sodium bicarbonate increases the amount of CO2 in the blood. Increased amounts of carbon dioxide in the blood also lowers pH of the blood, and this leads to respiratory acidosis.

Question 18

What are the indications for administering sodium bicarbonate?

Answer 18

Indications:
Sodium bicarbonate is primarily indicated when the patient was known to have metabolic acidosis prior to the cardiac arrest or when the patient has been in cardiac arrest for a prolonged period of time.

Question 19

What is a safe dosage of sodium bicarbonate?

Answer 19

Dosage:
1 mEq/kg can be given via IV bolus as an initial dose, followed by half of this does every 10 minutes. Administration of bicarbonate should be guided by arterial blood gas analysis to monitor the patient’s acid/base status. Inducing alkalosis should always be avoided.

Question 20

What is the main precaution when using sodium bicarbonate?

Answer 20

Sodium bicarbonate rapidly combines with acid to produce carbon dioxide, so good ventilation is essential to eliminate the carbon dioxide.

Question 21

Name for Positive Inotropic Drugs?

Answer 21

Positive inotropic drugs make your heart beat more strongly end efficiently.
Digoxin
Inamrinone
Dopamine
Dobutamine (Dobutrex)

Question 22

What is Inamrinone and what is it used for?

Answer 22

Inamrinone is a phosphodiesterase inhibitor or with positive inotropic effects and vasodilating effect, which decreases afternoon.together, these effects result in increased cardiac output it.
Indications:
It is used in the treatment of heart failure refractory and diuretics, vasodilators, and conventional inotropic agents.
Precautions:
Inamrinone may cause tachyarrhythmia, hypotension or thrombocytopenia.

Question 23

What are the indications and dosages of Dopamine?

Answer 23

Indications:
Dopamine is a second – line drug after atropine for symptomatic bradycardia. It is used for hypertension (systolic blood pressure equals 70 to 100 mmHg) with signs and symptoms of shock.
Dosage:
Effects are dose-dependent. Low doses (1 to 2 µg/kg per minute) stimulate the dopaminergic receptors to produce cerebral, renal, and mesenteric vasodilation.
Note: Mesenteric attaches to the intestinal track.
When administered at 2 to 10 µg/kg per minute dopamine stimulates the beta-1 and alpha receptors. The main effect is to increase cardiac output.
At doses greater than 10 µg-kg per minute, dopamine’s alpha – adrenergic effect predominates.

Question 24

What are the indications and dosages of the positive inotropic drug named dobutamine?

Answer 24

Synthetic catecholamine that stimulates beta-1 receptors. It has a strong positive inotropic effect, with less chronotropic effect then dopamine.
Indications:
Dobutamine is used for congestive heart failure or pulmonary congestion with systolic blood pressure of 70 – 100 mmHg and no signs of shock.
Dosage:
The usual infusion rate for dobutamine is 2–20 µg/kg per minute. It should be titrated so that rate does not increase greater than 10% of baseline.

Question 25

Explain what the anti-arrhythmia drug atropine is used for.

Answer 25

Parasympatholytic drug used with advanced heart disease due to increased parasympathetic tone.
Atropine increases heart rate.
Used to treat bradycardia.
Administered via IV in 0.5 to 1.0 mg, can be repeated at five minute intervals until patient’s heart rate reaches 60 bpm.
Very few side effects, but tachycardia is possible.

Question 26

Describe what the antiarrhythmic drug lidocaine is used for?

Answer 26

Lidocaine (Xylocaine) makes the heart more resistant to fibrillation and more responsive to defibrillation.
It is a long – standing antiarrhythmic, but recently lidocaine is not the first line of defense.
Used when a patient has not responded to epinephrine or defibrillation, lidocaine is useful in doses of 1.0 to 1.5 mg/kg, given every 3 to 5 minutes until a loading dose of 3 mg/kg is reached.
Prolonged administration can result in toxicity.

Question 27

What is the antiarrhythmic drug Amiodarone (Cordarone) used for?

Answer 27

Amiodarone is an antiarrhythmic that is useful in treating both atrial and ventricle tachycardia’s and for ventricle fibrillation.
Indications:
Amiodarone is indicated for supraventricular tachycardia, ventricular tachycardia, ventricular tachycardia without a pulse, and ventricular fibrillation.
Dosage:
Hundred and 50 mg of amiodarone is given over 10 minutes, followed by a 1 mg/minute infusion for 6 hours and then 0.5 mg/minute.
Dosage during cardiac arrest:
300 mg bolus, followed by 150 mg bolus 3–5 minutes later.
precautions:
Major adverse effects are hypotension and bradycardia, which can be prevented by slowing the rate of drug infusion and giving fluid, vasopressive, or chronotropic agents.

Question 28

What is the antiarrhythmic drug Procainamide (Pronestyl) used for?

Answer 28

It’s suppresses a variety of the ectopic arrhythmias.
It decreases automaticity in the ventricular muscle and Purkinje fibers.
Takes a long time to administer.
Maintenance dose is an IV infusion of 1–4 mg/minute.
If procainamide is given to rapidly or blood levels get too high, hypotension can occur.
Need to carefully monitored the patient and drug levels.

Question 29

Why is magnesium sulfate considered an antiarrhythmic drug?

Answer 29

Plays a major role in the sodium/potassium pump, and it is a physiologic calcium – channel blocker.