34. ACLS

Question 1

What is the first step in the ACLS adult cardiac arrest algorithm when discovering an unresponsive, pulseless patient?

A) Give oxygen first
B) Attach the defibrillator first
C) Initiate high-quality CPR
D) Intubate immediately

Answer 1

Correct Answer: C) Initiate high-quality CPR
Explanation:
High-quality chest compressions should always begin immediately for patients with no pulse and unresponsiveness in the ACLS sequence. Advanced airways and other interventions come after CPR initiation

Question 2

In the initial steps of ACLS cardiac arrest management, what should be done after starting CPR?

A) Administer adrenaline
B) Start IV fluids
C) Provide supplementary oxygen and attach defibrillator
D) Push sodium bicarbonate

Answer 2

Correct Answer: C) Provide supplementary oxygen and attach defibrillator
Explanation:
Oxygen and connecting the defibrillator come directly after compressions, before drug administration or invasive interventions.

Question 3

Which is the recommended sequence of actions for an unresponsive patient with no pulse according to ACLS?

A) CPR → oxygen → attach defibrillator
B) Oxygen only → defibrillator → CPR
C) Intubation → CPR → defibrillator
D) Attach defibrillator → CPR → oxygen

Answer 3

Answer: A) CPR → oxygen → attach defibrillator

Question 4

EMS finds a patient in cardiac arrest; CPR has just been started by a bystander. What is the next most important step?

A) Prepare for immediate intubation
B) Attach a defibrillator and give oxygen
C) Give sodium bicarbonate
D) Start adrenaline immediately

Answer 4

Answer: B) Attach a defibrillator and give oxygen

Question 5

Agonal rhythm on ECG is characterized by which of the following?

A) Regular narrow-complex tachycardia
B) Irregular broad QRS complexes due to firing of Bundle of His
C) Sinus rhythm with normal QRS
D) Classic tall peaked T waves

Answer 5

Correct Answer: B) Irregular broad QRS complexes due to firing of Bundle of His
Explanation:
Agonal rhythm reflects dying heart electrical activity—irregular, wide QRS generated by escape mechanisms. It often occurs during terminal events before/after asystole

Question 6

Which treatable cause of cardiac arrest can be suspected if the ECG shows S1Q3T3 pattern and clinical RV failure?

A) Tension pneumothorax
B) Hyperkalemia
C) Pulmonary embolism
D) Tamponade

Answer 6

Correct Answer: C) Pulmonary embolism
Explanation:
S1Q3T3 (S wave in lead I, Q wave in III, T wave inversion in III), RV failure, and Kussmaul’s sign are classic for massive pulmonary embolism

Question 7

Electrical alternans on ECG is a hallmark of which treatable cause of cardiac arrest?

A) Hypokalemia
B) Tamponade
C) Hypercalcemia
D) Torsades de pointes

Answer 7

Correct Answer: B) Tamponade
Explanation:
Electrical alternans (beat-to-beat QRS axis shift) results from swinging heart in pericardial effusion/tamponade—hallmark for its diagnosis

Question 8

Which electrolyte abnormality causes torsades de pointes and can lead to diaphragmatic paralysis before cardiac arrest?

A) Hypercalcemia
B) Hypokalemia
C) Hypernatremia
D) Hypermagnesemia

Answer 8

Correct Answer: B) Hypokalemia
Explanation:
Hypokalemia predisposes to torsades de pointes, muscle weakness, and can cause death via diaphragmatic paralysis

Question 9

Absent breath sounds on one side and acute cardiac arrest in a trauma patient suggests which diagnosis?

A) Myocardial infarction
B) Tamponade
C) Tension pneumothorax
D) Hyperkalemia

Answer 9

Correct Answer: C) Tension pneumothorax
Explanation:
Classic for tension pneumothorax in trauma: absent breath sounds, sudden collapse, obstructive shock/arrest

Question 10

Hyperkalemia-induced cardiac arrest typically presents initially with which rhythm disturbance?

A) Sinus tachycardia
B) Bradycardia then asystole
C) AV block with narrow QRS
D) Torsades de pointes only

Answer 10

Correct Answer: B) Bradycardia then asystole
Explanation:
Hyperkalemia often proceeds from bradycardia to widening QRS/asystole

Question 11

Classic ECG finding in cardiac tamponade is:
A) Electrical alternans
B) ST elevation
C) S1Q3T3 pattern
D) QT prolongation

Answer 11

Answer: A) Electrical alternans

Question 12

Best clue for massive pulmonary embolism on ECG:
A) ST elevation in V4–V6
B) S1Q3T3 pattern with RV strain
C) Peaked T waves
D) Electrical alternans

Answer 12

Answer: B) S1Q3T3 pattern with RV strain

Question 13

Torsades de pointes and diaphragmatic paralysis are most commonly associated with:
A) Hypermagnesemia
B) Hypercalcemia
C) Hypokalemia
D) Hypernatremia

Answer 13

Answer: C) Hypokalemia

Question 14

The first medication to be administered during ongoing CPR for refractory VF/pulseless VT, immediately after the second shock, is:

A) Amiodarone
B) Atropine
C) Epinephrine
D) Magnesium sulfate

Answer 14

Correct Answer: C) Epinephrine
Explanation:
Epinephrine is given as early as possible after the second shock in ACLS for VF/pVT. Amiodarone/lidocaine are added if arrhythmia persists after the third shock.

Question 15

In the management of ventricular fibrillation, what is the correct sequence following initial defibrillation?

A) Pulse check → amiodarone → oxygen
B) 2 minutes of chest compressions → IV/IO access
C) Directly give atropine and check rhythm
D) Give magnesium in all cases

Answer 15

Correct Answer: B) 2 minutes of chest compressions → IV/IO access
Explanation:
After each defibrillation, resume immediately with 2 minutes of CPR while IV/IO access is established and until next rhythm check.

Question 16

Which antiarrhythmic drug is recommended after three shocks plus epinephrine in VF/pVT arrest?

A) Atropine
B) Amiodarone
C) Verapamil
D) Adenosine

Answer 16

Correct Answer: B) Amiodarone
Explanation:
Amiodarone (or lidocaine) is recommended after epinephrine if VF/pVT persists despite defibrillation, after the third shock

Question 17

How often should rhythm and pulse checks be performed during CPR for VF/pulseless VT?

A) Every 1 minute
B) Every 2 minutes
C) Every 5 minutes
D) Only after ROSC

Answer 17

Correct Answer: B) Every 2 minutes
Explanation:
Rhythm and pulse are checked every 2 minutes, minimizing CPR interruptions

Question 18

During ACLS, which statement is true regarding defibrillation for shockable rhythms?

A) Three shocks are never recommended
B) Up to three attempts can be given, pausing for compressions between shocks
C) Defibrillation is not used in VF
D) Synchronized cardioversion is always preferred

Answer 18

Correct Answer: B) Up to three attempts can be given, pausing for compressions between shocks
Explanation:
Three escalating defibrillation attempts are standard, with high-quality CPR between and after each.

Question 19

During the ACLS algorithm for VF/pulseless VT, the recommended antiarrhythmic after epinephrine and persistent arrhythmia is:

A) Amiodarone
B) Atropine
C) Adenosine
D) Metoprolol

Answer 19

Answer: A) Amiodarone

Question 20

In the ACLS algorithm for pulseless VF/pVT, how often is adrenaline administered?

A) Every 1 minute
B) Every 3–5 minutes
C) Every 10 minutes
D) Only once

Answer 20

Answer: B) Every 3–5 minutes

Question 21

Which of the following is the drug of choice for asystole and pulseless electrical activity (PEA) during ACLS?

A) Atropine
B) Amiodarone
C) Epinephrine
D) Lidocaine

Answer 21

Correct Answer: C) Epinephrine
Explanation:
For both asystole and PEA, IV epinephrine 1 mg is recommended as soon as possible, and may be repeated every 3–5 minutes during resuscitation. Amiodarone and lidocaine are for refractory VF/pVT, while atropine is for bradycardia, not asystole/PEA

Question 22

What is the immediate next step after confirming asystole or PEA in a patient with cardiac arrest?

A) Attempt DC shock
B) Begin high-quality CPR and give epinephrine
C) Start magnesium sulfate
D) Push adenosine rapidly

Answer 22

Correct Answer: B) Begin high-quality CPR and give epinephrine
Explanation:
Both asystole and PEA are non-shockable rhythms; the mainstay of management is uninterrupted high-quality CPR along with early epinephrine, not defibrillation

Question 23

While managing a patient with asystole, which ACLS measure should be performed every 2 minutes?

A) Epinephrine bolus
B) Synchronized cardioversion
C) Switching providers for chest compressions and checking the rhythm
D) Atropine IV

Answer 23

Correct Answer: C) Switching providers for chest compressions and checking the rhythm
Explanation:
After each 2-minute cycle of CPR, rhythm (and pulse if organized) should be checked and compressors changed to maintain efficacy and reduce fatigue.

Question 24

During persistent asystole/PEA despite optimal CPR and repeated epinephrine, what is the next key action?

A) Attempt defibrillation immediately
B) Administer amiodarone
C) Search for and treat reversible causes (Hs/Ts)
D) Prepare for synchronized cardioversion

Answer 24

Correct Answer: C) Search for and treat reversible causes (Hs/Ts)
Explanation:
Continuing high-quality CPR, epinephrine, and identifying/treating reversible etiologies is critical, as defibrillation and amiodarone are not beneficial in asystole/PEA.

Question 25

Which of the following is TRUE regarding the use of DC shock in asystole/PEA? A) DC shock is first-line B) DC shock is only for shockable rhythms C) Used immediately after CPR D) DC shock is always used in PEA

Answer 25

Correct Answer: B) DC shock is only for shockable rhythms Explanation: Neither asystole nor PEA are treated with defibrillation; prompt CPR and drugs are mainstays

Question 26

For a cardiac arrest patient in asystole, how often should epinephrine be repeated during resuscitation? A) Every 30 seconds B) Every 3–5 minutes C) Every 15 minutes D) Once only

Answer 26

Answer: B) Every 3–5 minutes

Question 27

After two cycles of CPR in asystole, what is the next action? A) Synchronized shock B) Rhythm check and treat Hs/Ts C) Only stop CPR D) Push amiodarone IV

Answer 27

Answer: B) Rhythm check and treat Hs/Ts

Question 28

Which is the correct drug and dose for the first antiarrhythmic administered in shock-refractory VF/pulseless VT? A) Amiodarone 300 mg IV bolus B) Lidocaine 0.1 mg/kg IV C) Atropine 1 mg IV D) Amiodarone 25 mg IV bolus

Answer 28

Correct Answer: A) Amiodarone 300 mg IV bolus Explanation: For VF/pVT unresponsive to shock and epinephrine, amiodarone 300 mg IV/IO is indicated. If needed, a second dose of 150 mg IV/IO is given.

Question 29

How should breaths be managed once an advanced airway is placed during CPR? A) 1 breath every 12 seconds, pause compressions B) 1 breath every 6 seconds with continuous chest compressions C) 2 breaths after every 30 compressions D) 12 breaths per minute, with long pauses

Answer 29

Correct Answer: B) 1 breath every 6 seconds with continuous chest compressions Explanation: Once advanced airway (ETT or supraglottic) is in place, continuous chest compressions should be coordinated with 1 breath every 6 seconds (10 breaths/min), without interruptions

Question 30

For lidocaine as a substitute antiarrhythmic in refractory VF/pVT, which is the recommended initial and repeat dose? A) 0.1 mg/kg and 0.25 mg/kg B) 1–1.5 mg/kg, repeat 0.5–0.75 mg/kg C) 5 mg/kg, repeat after 2 min D) 2–4 mg/kg, single dose only

Answer 30

Correct Answer: B) 1–1.5 mg/kg, repeat 0.5–0.75 mg/kg Explanation: Lidocaine dosing for refractory VF/pVT is 1–1.5 mg/kg IV/IO initially, followed by 0.5–0.75 mg/kg in subsequent doses

Question 31

Which of the following is first-line for ventricular fibrillation/pulseless VT, asystole, AND post-MI ventricular tachycardia? A) Epinephrine for all B) Epinephrine for arrest, amiodarone post-MI VT C) Atropine for asystole D) Lidocaine for asystole only

Answer 31

Correct Answer: B) Epinephrine for arrest, amiodarone post-MI VT Explanation: Epinephrine is first-line for VF/pulseless VT and asystole. Amiodarone is first-line for post-MI VT, especially if sustained or recurrent.

Question 32

What is the recommended oxygen saturation (SpO₂) target for adult patients in the immediate post-cardiac arrest period (ROSC)? A) 75–80% B) 100% at all times C) 92–98% D) Less than 90%

Answer 32

Correct Answer: C) 92–98% Explanation: After ROSC, hyperoxia increases risk of worsened neurological outcome; hence, SpO₂ should be maintained between 92–98%

Question 33

Which of the following PaCO₂ (arterial CO₂ tension) targets is recommended in post-cardiac arrest care? A) <25 mmHg B) 35–45 mmHg C) 55–65 mmHg D) >70 mmHg

Answer 33

Correct Answer: B) 35–45 mmHg Explanation: Normocapnia (PaCO₂ 35–45 mmHg) is the ventilation goal post-ROSC, as both hypo- and hypercapnia worsen neurologic outcomes

Question 34

In the initial stabilization phase after ROSC, what is the recommended respiratory rate for mechanically ventilated adults? A) 30 breaths/min B) 10 breaths/min C) 5 breaths/min D) 25 breaths/min

Answer 34

Correct Answer: B) 10 breaths/min Explanation: The American Heart Association suggests starting at 10 breaths/min while fine-tuning parameters according to blood gases

Question 35

In post–cardiac arrest care, what is the minimum target for mean arterial pressure (MAP) in most adults? A) 40 mmHg B) 55 mmHg C) 65 mmHg D) 100 mmHg

Answer 35

Correct Answer: C) 65 mmHg Explanation: MAP should be >65 mm Hg (and systolic BP >90 mm Hg) to optimize cerebral perfusion and reduce risk of secondary brain injury after ROSC

Question 36

What investigation is routinely recommended after initial stabilization of a post–cardiac arrest patient who has achieved ROSC? A) 12-lead ECG B) Troponin T only C) Portable X-ray D) Renal ultrasound

Answer 36

Correct Answer: A) 12-lead ECG Explanation: A 12-lead ECG is required to identify acute coronary syndromes or other lethal arrhythmias and guide further management

Question 37

What is the next best airway measure after ROSC in an unresponsive patient? A) Nasal cannula B) Early endotracheal intubation C) Mouth-to-mouth ventilation D) Non-rebreather mask only

Answer 37

Answer: B) Early endotracheal intubation

Question 38

A patient post-cardiac arrest has PaCO₂ of 55 mm Hg and SpO₂ of 91%. Which adjustment is correct? A) Accept both values as they are B) Increase rate or tidal volume to lower PaCO₂ and increase inspired O₂ C) Decrease ventilation D) Lower the oxygen further

Answer 38

Answer: B) Increase rate or tidal volume to lower PaCO₂ and increase inspired O₂

Question 39

In post–cardiac arrest care, which patients are candidates for targeted temperature management (TTM)? A) All patients after any cardiac arrest B) Only patients with large anterior STEMI C) Patients who remain comatose after ROSC and do not follow commands D) Only patients with pre-hospital cardiac arrest

Answer 39

Correct Answer: C) Patients who remain comatose after ROSC and do not follow commands Explanation: TTM (32–36°C for 24 hours) should be started ASAP for patients who are comatose post-arrest (do not follow commands), as recommended by AHA and international guidelines.

Question 40

What is the target temperature range for TTM after cardiac arrest, and how long is it maintained? A) 28–30°C for 12 hours B) 34–37°C for 2 days C) 32–36°C for 24 hours D) <30°C for 48 hours

Answer 40

Correct Answer: C) 32–36°C for 24 hours Explanation: Current consensus supports cooling to 32–36°C for 24 hours for comatose patients, with no strong evidence favoring a specific temperature within this range, as long as fever (>37.5°C) is avoided

Question 41

A patient with post-arrest cardiogenic shock unresponsive to vasopressors should be considered for which next intervention? A) Calcium gluconate infusion B) Inhaled nitric oxide C) Mechanical circulatory support (Impella, intra-aortic balloon pump) D) High-dose corticosteroids

Answer 41

Correct Answer: C) Mechanical circulatory support (Impella, intra-aortic balloon pump) Explanation: Refractory cardiogenic shock after cardiac arrest may require short-term mechanical support—devices like Impella or IABP provide hemodynamic stabilization when vasopressors fail.

Question 42

If a comatose post-arrest patient is being managed with TTM, what additional monitoring/interventions are recommended? A) Continuous EEG, brain CT, and routine critical care measures B) Only daily troponins C) No neuro-monitoring if CT is normal D) Stop supportive care after 6 hours

Answer 42

Correct Answer: A) Continuous EEG, brain CT, and routine critical care measures Explanation: Comatose patients under TTM require ongoing neuro-monitoring for seizures (EEG), brain imaging (often CT), and continued multisystem support

Question 43

Therapeutic hypothermia/TTM after cardiac arrest provides protection primarily against: A) Sepsis and dehydration B) Cerebral and cardiac ischemic reperfusion injury C) Coronary plaque rupture D) Acute renal failure

Answer 43

Correct Answer: B) Cerebral and cardiac ischemic reperfusion injury Explanation: TTM is neuro- and cardioprotective, reducing damage from post-ischemic reperfusion at the cellular and organ levels

Question 44

Which of the following is a standard indication for TTM/hypothermia post–cardiac arrest? A) Awake patient following commands B) Comatose patient not following commands C) STEMI on ECG only D) Hypotension refractory to fluids

Answer 44

Answer: B) Comatose patient not following commands

Question 45

Preferred target temperature range for TTM in comatose survivors of cardiac arrest is: A) 24–28°C B) 32–36°C C) 38–40°C D) <28°C

Answer 45

Answer: B) 32–36°C

Question 46

Impella and intra-aortic balloon pump are considered in post-arrest for: A) Acute pulmonary embolism B) Refractory cardiogenic shock C) Electrolyte imbalance D) Bradyarrhythmias

Answer 46

Answer: B) Refractory cardiogenic shock

Question 47

Most evidence-based protective effect of therapeutic hypothermia after cardiac arrest is: A) Hepatic salvage B) Neuroprotection C) Nephroprotection D) Prevention of arrhythmia

Answer 47

Answer: B) Neuroprotection