Question 1: Defibrillation
Q: A 62-year-old male collapses in the emergency department waiting room. The cardiac monitor
reveals coarse ventricular fibrillation. Which of the following is the most critical immediate
intervention?
A: Initiate cardiopulmonary resuscitation at a ratio of 30:2
B: Establish intravenous access for antiarrhythmic administration
C: Deliver an unsynchronized shock of 120 to 200 joules (biphasic)
D: Perform endotracheal intubation to secure the airway
Correct Answer: C
Rationale Focus: Priority intervention for shockable rhythms
Rationale: In adult cardiac arrest with a shockable rhythm (ventricular fibrillation or pulseless
ventricular tachycardia), early defibrillation is the most critical intervention and takes precedence
over all other advanced life support measures. The likelihood of successful defibrillation decreases
rapidly over time. The recommended initial biphasic energy dose is 120 to 200 joules, and the shock
must be delivered in unsynchronized mode to allow the defibrillator to discharge instantly without
sensing the QRS complex, which is absent in ventricular fibrillation.
Question 2: Reversible Causes
Q: A 54-year-old female with end-stage renal disease is in cardiac arrest. The primary rhythm on the
monitor is pulseless electrical activity (PEA). The team has been performing high-quality CPR and
administering epinephrine, but return of spontaneous circulation has not been achieved. Which of the
following reversible causes is most likely contributing to this patient's PEA arrest?
A: Tension pneumothorax
B: Hyperkalemia
C: Hypothermia
D: Cardiac tamponade
Correct Answer: B
Rationale Focus: Identifying reversible causes (H's and T's) in specific clinical contexts
Rationale: In patients with end-stage renal disease, the accumulation of potassium due to impaired
renal excretion places them at extremely high risk for life-threatening hyperkalemia. Hyperkalemia
alters the resting membrane potential of cardiac myocytes, leading to conduction abnormalities,
arrhythmias, and ultimately PEA or asystole. While all the listed options are reversible causes of PEA,
hyperkalemia is the most statistically probable in a patient with renal failure and should prompt
immediate administration of calcium chloride, insulin, and glucose.
,Question 3: Pharmacology
Q: During a ventricular fibrillation arrest, a patient has received two defibrillation shocks and high-
quality CPR is in progress. Intravenous access has just been established. Which of the following is the
correct initial dose and timing of epinephrine for this patient?
A: 1 mg IV push, administered after the second shock and every 3 to 5 minutes thereafter
B: 0.5 mg IV push, administered after the third shock and every 5 to 10 minutes thereafter
C: 2 mg IV push, administered immediately upon IV access and every 3 to 5 minutes thereafter
D: 1 mg IV push, administered prior to the first defibrillation attempt
Correct Answer: A
Rationale Focus: Epinephrine dosing and timing in shockable cardiac arrest
Rationale: According to ACLS guidelines, for shockable rhythms (VF/pVT), epinephrine 1 mg should be
administered intravenously or intraosseously after the second defibrillation attempt, while high-
quality CPR is in progress. It should subsequently be repeated every 3 to 5 minutes. Epinephrine acts
primarily as an alpha-adrenergic agonist, causing peripheral vasoconstriction, which increases
coronary and cerebral perfusion pressures during CPR.
Question 4: Post-Cardiac Arrest Care
Q: Following return of spontaneous circulation (ROSC) after a prolonged out-of-hospital cardiac arrest,
a 68-year-old male is unresponsive and intubated. His oxygen saturation is 100%, and his blood
pressure is 88/50 mmHg. Which of the following is the most appropriate immediate target for
oxygenation and ventilation?
A: Administer 100% oxygen to prevent hypoxia and hyperventilate to reduce intracranial pressure
B: Titrate FiO2 to maintain SpO2 at 92% to 98% and target a PaCO2 of 35 to 45 mmHg
C: Titrate FiO2 to maintain SpO2 at 85% to 90% and target a PaCO2 of 30 to 35 mmHg
D: Administer 100% oxygen and target a PaCO2 of 45 to 50 mmHg to ensure adequate cerebral blood
flow
Correct Answer: B
Rationale Focus: Post-ROSC oxygenation and ventilation targets
Rationale: After ROSC, avoiding hyperoxia is critical because excessive arterial oxygen can generate
free radicals and worsen reperfusion injury. Therefore, the fraction of inspired oxygen (FiO2) should
be titrated to maintain a peripheral oxygen saturation (SpO2) of 92% to 98%. Additionally, ventilation
should be targeted to achieve normocapnia (PaCO2 of 35 to 45 mmHg). Hyperventilation and
resultant hypocapnia cause cerebral vasoconstriction, reducing cerebral blood flow and worsening
, ischemia, while hypercapnia can cause excessive cerebral vasodilation and increase intracranial
pressure.
Question 5: Bradycardia Algorithm
Q: A 74-year-old female presents to the emergency department complaining of severe dizziness and
generalized weakness. The cardiac monitor shows a sinus bradycardia at a rate of 38 beats per
minute. Her blood pressure is 74/40 mmHg, and she is diaphoretic and confused. Which of the
following is the most appropriate initial intervention?
A: Administer adenosine 6 mg rapid IV push
B: Prepare for immediate transcutaneous pacing
C: Administer dopamine infusion at 2 to 20 mcg/kg/min
D: Observe and monitor for spontaneous resolution
Correct Answer: B
Rationale Focus: Management of unstable bradycardia
Rationale: This patient is presenting with symptomatic bradycardia with signs of hemodynamic
instability (hypotension, altered mental status, diaphoresis). When bradycardia causes severe
hemodynamic compromise, immediate transcutaneous pacing is the intervention of choice. While
intravenous chronotropic agents like atropine or dopamine may be used, they are typically adjuncts or
temporizing measures, and pacing should not be delayed in an unstable patient. Adenosine is
contraindicated as it will further suppress the sinoatrial and atrioventricular nodes.
Question 6: Tachycardia Algorithm
Q: A 45-year-old male presents with a sudden onset of palpitations and light-headedness. His heart
rate is 180 beats per minute, and the cardiac monitor reveals a regular, narrow-complex tachycardia.
Vagal maneuvers have failed to convert the rhythm. His blood pressure is 110/70 mmHg, and he is
alert and oriented. What is the next most appropriate pharmacological intervention?
A: Synchronized cardioversion at 50 to 100 joules
B: Adenosine 6 mg rapid IV push followed by a normal saline flush
C: Amiodarone 150 mg IV over 10 minutes
D: Verapamil 2.5 mg slow IV push
Correct Answer: B
Rationale Focus: Pharmacological management of stable narrow-complex tachycardia
Rationale: For a patient with a stable, regular narrow-complex tachycardia (suspected
supraventricular tachycardia) that does not respond to vagal maneuvers, adenosine is the first-line
Q: A 62-year-old male collapses in the emergency department waiting room. The cardiac monitor
reveals coarse ventricular fibrillation. Which of the following is the most critical immediate
intervention?
A: Initiate cardiopulmonary resuscitation at a ratio of 30:2
B: Establish intravenous access for antiarrhythmic administration
C: Deliver an unsynchronized shock of 120 to 200 joules (biphasic)
D: Perform endotracheal intubation to secure the airway
Correct Answer: C
Rationale Focus: Priority intervention for shockable rhythms
Rationale: In adult cardiac arrest with a shockable rhythm (ventricular fibrillation or pulseless
ventricular tachycardia), early defibrillation is the most critical intervention and takes precedence
over all other advanced life support measures. The likelihood of successful defibrillation decreases
rapidly over time. The recommended initial biphasic energy dose is 120 to 200 joules, and the shock
must be delivered in unsynchronized mode to allow the defibrillator to discharge instantly without
sensing the QRS complex, which is absent in ventricular fibrillation.
Question 2: Reversible Causes
Q: A 54-year-old female with end-stage renal disease is in cardiac arrest. The primary rhythm on the
monitor is pulseless electrical activity (PEA). The team has been performing high-quality CPR and
administering epinephrine, but return of spontaneous circulation has not been achieved. Which of the
following reversible causes is most likely contributing to this patient's PEA arrest?
A: Tension pneumothorax
B: Hyperkalemia
C: Hypothermia
D: Cardiac tamponade
Correct Answer: B
Rationale Focus: Identifying reversible causes (H's and T's) in specific clinical contexts
Rationale: In patients with end-stage renal disease, the accumulation of potassium due to impaired
renal excretion places them at extremely high risk for life-threatening hyperkalemia. Hyperkalemia
alters the resting membrane potential of cardiac myocytes, leading to conduction abnormalities,
arrhythmias, and ultimately PEA or asystole. While all the listed options are reversible causes of PEA,
hyperkalemia is the most statistically probable in a patient with renal failure and should prompt
immediate administration of calcium chloride, insulin, and glucose.
,Question 3: Pharmacology
Q: During a ventricular fibrillation arrest, a patient has received two defibrillation shocks and high-
quality CPR is in progress. Intravenous access has just been established. Which of the following is the
correct initial dose and timing of epinephrine for this patient?
A: 1 mg IV push, administered after the second shock and every 3 to 5 minutes thereafter
B: 0.5 mg IV push, administered after the third shock and every 5 to 10 minutes thereafter
C: 2 mg IV push, administered immediately upon IV access and every 3 to 5 minutes thereafter
D: 1 mg IV push, administered prior to the first defibrillation attempt
Correct Answer: A
Rationale Focus: Epinephrine dosing and timing in shockable cardiac arrest
Rationale: According to ACLS guidelines, for shockable rhythms (VF/pVT), epinephrine 1 mg should be
administered intravenously or intraosseously after the second defibrillation attempt, while high-
quality CPR is in progress. It should subsequently be repeated every 3 to 5 minutes. Epinephrine acts
primarily as an alpha-adrenergic agonist, causing peripheral vasoconstriction, which increases
coronary and cerebral perfusion pressures during CPR.
Question 4: Post-Cardiac Arrest Care
Q: Following return of spontaneous circulation (ROSC) after a prolonged out-of-hospital cardiac arrest,
a 68-year-old male is unresponsive and intubated. His oxygen saturation is 100%, and his blood
pressure is 88/50 mmHg. Which of the following is the most appropriate immediate target for
oxygenation and ventilation?
A: Administer 100% oxygen to prevent hypoxia and hyperventilate to reduce intracranial pressure
B: Titrate FiO2 to maintain SpO2 at 92% to 98% and target a PaCO2 of 35 to 45 mmHg
C: Titrate FiO2 to maintain SpO2 at 85% to 90% and target a PaCO2 of 30 to 35 mmHg
D: Administer 100% oxygen and target a PaCO2 of 45 to 50 mmHg to ensure adequate cerebral blood
flow
Correct Answer: B
Rationale Focus: Post-ROSC oxygenation and ventilation targets
Rationale: After ROSC, avoiding hyperoxia is critical because excessive arterial oxygen can generate
free radicals and worsen reperfusion injury. Therefore, the fraction of inspired oxygen (FiO2) should
be titrated to maintain a peripheral oxygen saturation (SpO2) of 92% to 98%. Additionally, ventilation
should be targeted to achieve normocapnia (PaCO2 of 35 to 45 mmHg). Hyperventilation and
resultant hypocapnia cause cerebral vasoconstriction, reducing cerebral blood flow and worsening
, ischemia, while hypercapnia can cause excessive cerebral vasodilation and increase intracranial
pressure.
Question 5: Bradycardia Algorithm
Q: A 74-year-old female presents to the emergency department complaining of severe dizziness and
generalized weakness. The cardiac monitor shows a sinus bradycardia at a rate of 38 beats per
minute. Her blood pressure is 74/40 mmHg, and she is diaphoretic and confused. Which of the
following is the most appropriate initial intervention?
A: Administer adenosine 6 mg rapid IV push
B: Prepare for immediate transcutaneous pacing
C: Administer dopamine infusion at 2 to 20 mcg/kg/min
D: Observe and monitor for spontaneous resolution
Correct Answer: B
Rationale Focus: Management of unstable bradycardia
Rationale: This patient is presenting with symptomatic bradycardia with signs of hemodynamic
instability (hypotension, altered mental status, diaphoresis). When bradycardia causes severe
hemodynamic compromise, immediate transcutaneous pacing is the intervention of choice. While
intravenous chronotropic agents like atropine or dopamine may be used, they are typically adjuncts or
temporizing measures, and pacing should not be delayed in an unstable patient. Adenosine is
contraindicated as it will further suppress the sinoatrial and atrioventricular nodes.
Question 6: Tachycardia Algorithm
Q: A 45-year-old male presents with a sudden onset of palpitations and light-headedness. His heart
rate is 180 beats per minute, and the cardiac monitor reveals a regular, narrow-complex tachycardia.
Vagal maneuvers have failed to convert the rhythm. His blood pressure is 110/70 mmHg, and he is
alert and oriented. What is the next most appropriate pharmacological intervention?
A: Synchronized cardioversion at 50 to 100 joules
B: Adenosine 6 mg rapid IV push followed by a normal saline flush
C: Amiodarone 150 mg IV over 10 minutes
D: Verapamil 2.5 mg slow IV push
Correct Answer: B
Rationale Focus: Pharmacological management of stable narrow-complex tachycardia
Rationale: For a patient with a stable, regular narrow-complex tachycardia (suspected
supraventricular tachycardia) that does not respond to vagal maneuvers, adenosine is the first-line
