CPR - Certified Paramedic Response Cardiac Arrest Pharmacology Questions and Answers 1 — Questions and Answers
Question 1: A 68-year-old male is in cardiac arrest with a persistent rhythm of Ventricular Fibrillation after three defibrillation attempts and a dose of epinephrine. According to the latest ACLS guidelines, which of the following is the most appropriate next pharmacological intervention?
- Administer Amiodarone 300 mg IV/IO push. (Correct answer)
- Administer an additional dose of Epinephrine 1 mg.
- Administer Lidocaine 1.5 mg/kg IV/IO.
- Administer Sodium Bicarbonate 1 mEq/kg.
Correct answer: Administer Amiodarone 300 mg IV/IO push.
For refractory Ventricular Fibrillation or pulseless Ventricular Tachycardia (VF/pVT) that is unresponsive to defibrillation and a vasopressor, the next line of treatment is an antiarrhythmic. Amiodarone, in an initial dose of 300 mg IV/IO, is the primary antiarrhythmic recommended in ACLS guidelines. While Lidocaine is an alternative, Amiodarone is generally preferred. Another dose of epinephrine would be administered later, and Sodium Bicarbonate is not routinely recommended.
Question 2: During the management of a patient in asystole, what is the recommended dose and frequency of epinephrine administration?
- 0.5 mg every 5-10 minutes
- 1 mg every 1-2 minutes
- 1 mg every 3-5 minutes (Correct answer)
- 2 mg every 3-5 minutes
Correct answer: 1 mg every 3-5 minutes
Current ACLS guidelines recommend administering 1 mg of epinephrine every 3 to 5 minutes during cardiac arrest for both shockable and non-shockable rhythms like asystole. The goal of epinephrine is to increase myocardial and cerebral blood flow through its vasoconstrictive (alpha-adrenergic) effects.
Question 3: Which of the following is the primary reason for administering epinephrine during cardiac arrest?
- To increase the heart's contractility and rate.
- To directly convert Ventricular Fibrillation to a sinus rhythm.
- To cause peripheral vasoconstriction and improve coronary perfusion. (Correct answer)
- To correct metabolic acidosis.
Correct answer: To cause peripheral vasoconstriction and improve coronary perfusion.
The primary benefit of epinephrine in cardiac arrest is its alpha-adrenergic effect, which causes systemic vasoconstriction. This action increases aortic diastolic pressure, leading to improved coronary and cerebral perfusion pressures, which is critical for achieving Return of Spontaneous Circulation (ROSC). While it has beta-adrenergic effects that increase contractility and rate, the alpha-mediated vasoconstriction is the key mechanism of action in this setting.
Question 4: A paramedic is treating a patient in cardiac arrest with shock-refractory Ventricular Fibrillation. Amiodarone is unavailable. Which medication is the most appropriate alternative?
- Magnesium Sulfate
- Lidocaine (Correct answer)
- Procainamide
- Atropine
Correct answer: Lidocaine
Lidocaine is recognized as the primary alternative antiarrhythmic agent to amiodarone for the treatment of shock-refractory VF/pVT. The standard initial dose is 1 to 1.5 mg/kg. Magnesium Sulfate is indicated for Torsades de Pointes, and Atropine is used for symptomatic bradycardia, not VF.
Question 5: In which of the following cardiac arrest situations is the administration of epinephrine recommended as early as feasible once IV/IO access is established?
- Ventricular Fibrillation
- Pulseless Ventricular Tachycardia
- Pulseless Electrical Activity (PEA) (Correct answer)
- Only after the third defibrillation attempt, regardless of rhythm.
Correct answer: Pulseless Electrical Activity (PEA)
For non-shockable rhythms, such as Pulseless Electrical Activity (PEA) and asystole, high-quality CPR and early administration of epinephrine are the cornerstones of treatment. Unlike shockable rhythms where defibrillation is the priority, in PEA, epinephrine should be given as soon as possible after access is obtained to improve perfusion.
Question 6: What is the correct initial IV/IO dose of amiodarone for a patient with VF/pVT that is unresponsive to CPR, defibrillation, and vasopressor therapy?
- 150 mg over 10 minutes
- 1 mg/min infusion
- 300 mg push (Correct answer)
- 5 mg/kg push
Correct answer: 300 mg push
The initial dose of amiodarone for refractory VF/pVT in an adult cardiac arrest is a 300 mg IV or IO bolus (push). A second dose of 150 mg can be considered if VF/pVT persists. The 5 mg/kg dose was used in some trials but 300 mg is the standard recommended dose.
CPR - Certified Paramedic Response Cardiac Arrest Pharmacology Questions and Answers 1
A 68-year-old male is in cardiac arrest with a persistent rhythm of Ventricular Fibrillation after three defibrillation attempts and a dose of epinephrine.
According to the latest ACLS guidelines, which of the following is the most appropriate next pharmacological intervention?