ICU Basics

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15 free ACLS practice questions from the ICU Basics bank of 297, each with the answer and a rationale for every choice. Try them here, then practice the rest free in your browser. No account, no ads.

The AHA ACLS provider written exam has 50 questions. AHA does not publish a topic breakdown, so each mock draws questions at random from all adult ACLS topics.

From the live ICU Basics bank. How questions are written and reviewed · ACLS Course Exam Guide

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Question 1 · Basic Life Support (BLS)

During a staff update, a nurse educator explains that the 2025 AHA adult guideline now starts each cycle of severe choking care with back blows before abdominal thrusts. Which finding BEST explains how this change benefits patients?

  1. The adult sequence now matches the infant and child sequences
  2. Back blows produce higher airway pressures than chest compressions
  3. Randomized trials showed abdominal thrusts to be ineffective in adults
  4. Back blows were linked to higher relief rates and fewer injuries
Show the answer and rationale

Answer: D

  • A. Consistency with pediatric guidelines is why the adult cycle alternates 5 and 5, but it is a teaching benefit, not the finding about patient outcomes.
  • B. No such comparison underlies the change; chest compressions are themselves described as producing enough airway pressure to expel a foreign body.
  • C. There are no randomized trials comparing choking interventions; abdominal thrusts remain part of every cycle.
  • D. Correct. In a cohort of 709 people with airway obstruction, back blows were associated with higher rates of relief and fewer injuries than abdominal thrusts.

The 2025 AHA adult BLS guideline found no randomized trials comparing choking interventions. A population-based cohort study of 709 people with foreign-body airway obstruction found back blows associated with better relief rates and fewer injuries than abdominal thrusts, and case reports describe fatal injuries such as aortic dissection and gastric rupture after abdominal thrusts. The writing group chose alternating sets of 5 back blows and 5 abdominal thrusts partly for consistency with infant and pediatric guidelines, which already used this approach, making the sequence easier to learn across ages.

Sources: AHA 2025 Part 7: Adult BLS

Question 2 · Rhythm Recognition

An ICU patient with a radial arterial line is in PEA arrest. During compressions, the arterial tracing shows only compression spikes. At the 2-minute rhythm check, the monitor shows sinus rhythm at 98/min, and the arterial line now shows a pulsatile waveform reading 94/56. Which action should come NEXT?

  1. Confirm a palpable pulse, then begin post-arrest care
  2. Give the scheduled epinephrine dose, then resume compressions
  3. Scan for cardiac motion with ultrasound before deciding
  4. Resume compressions until ETCO₂ rises above 40 mm Hg
Show the answer and rationale

Answer: A

  • A. Correct. A new arterial waveform during a check that shows an organized rhythm may indicate ROSC, and the guideline advises confirming that it matches a palpable pulse.
  • B. Arrest-dose epinephrine is for a patient without circulation. The arterial waveform suggests circulation has returned, which must be checked first.
  • C. Point-of-care ultrasound in arrest is not well established and tends to lengthen pauses; the arterial line already answers the question faster.
  • D. No absolute ETCO₂ cutoff for ROSC has been identified, and restarting compressions on a perfusing rhythm ignores the arterial data.

When an arterial line is in place, the 2025 guideline allows it to be used to detect ROSC, both during compressions and when a rhythm check shows an organized rhythm. The development of an arterial waveform or a sudden rise in diastolic pressure suggests ROSC, but the waveform should be correlated with a palpable pulse before stopping CPR. An abrupt rise in ETCO₂ is another clue, often more than 10 mm Hg, yet ROSC can occur with smaller rises. Once ROSC is confirmed, the team shifts to post-arrest care: oxygenation, ventilation, blood pressure targets and a 12-lead ECG.

Sources: AHA 2025 Part 9: Adult ALS

Question 3 · ACLS Pharmacology

A 68-kg patient with an inferior STEMI is at a hospital where primary PCI cannot be performed in time, and tenecteplase is ordered. Which dose and administration should the nurse verify?

  1. 35 mg given as a single IV bolus over 5 seconds
  2. 50 mg as a single IV bolus, the maximum dose
  3. 15 mg IV bolus, then 50 mg over 30 minutes
  4. 17.5 mg as a single IV bolus over 5 seconds
Show the answer and rationale

Answer: A

  • A. Correct. The STEMI label assigns 35 mg to patients from 60 to under 70 kg, given as one bolus over about 5 seconds.
  • B. 50 mg is reserved for patients weighing 90 kg or more; giving it at 68 kg raises bleeding risk without added benefit.
  • C. This is the start of the accelerated alteplase regimen for a patient over 67 kg, which continues with a further 35 mg over 60 minutes; tenecteplase is a single bolus.
  • D. This is the acute ischemic stroke dose for this weight band, half the STEMI dose, and it would undertreat the coronary occlusion.

Tenecteplase for STEMI is dosed by weight band in 5-mg steps, from 30 mg under 60 kg to a maximum of 50 mg at 90 kg or more, as one IV bolus over 5 seconds. The stroke indication uses half these doses, and alteplase for myocardial infarction needs a 90-minute accelerated infusion, so the drug, indication and weight are all checked before the bolus. Tenecteplase is incompatible with dextrose, which means a dextrose line is flushed with saline before and after it, and the STEMI trials gave aspirin and heparin with it.

Sources: FDA Prescribing Information (DailyMed)

Question 4 · ACLS Algorithms

A 48-year-old had 20 minutes of pressure-like chest discomfort 3 hours ago and is pain free on arrival. Data are: BP 132/80, HR 78, SpO₂ 98% on room air. The 12-lead ECG shows no ST-segment or T-wave changes, the first high-sensitivity troponin is below the reference limit, and the TIMI score is low. According to the ACS algorithm, which plan is MOST appropriate?

  1. Monitoring in an ED chest pain unit with serial ECGs and troponins
  2. Emergent coronary angiography within 2 hours
  3. Fibrinolytic therapy, since the pain began less than 12 hours ago
  4. A heparin infusion and transfer to a PCI-capable center
Show the answer and rationale

Answer: A

  • A. Correct. A normal or nondiagnostic ECG with a low-risk score places the patient in the low- to intermediate-risk branch, where the algorithm advises admission to a chest pain unit or appropriate bed for further monitoring.
  • B. Very early angiography is for NSTE-ACS with refractory ischemic pain or hemodynamic or electrical instability; this patient is pain free, stable and has no high-risk feature.
  • C. The 12-hour window applies to the STEMI branch of the algorithm; without ST elevation, fibrinolysis has no role, and the bleeding risk would be taken on without benefit.
  • D. Anticoagulation and transfer for angiography follow once troponin is elevated or a high-risk feature appears; ACS has not yet been established in this patient.

The 2025 AHA ACS algorithm sorts patients without ST elevation by risk, using a validated score such as TIMI or GRACE. A normal or nondiagnostic ECG with a low-risk score is low- to intermediate-risk NSTE-ACS, and the algorithm advises considering admission to an ED chest pain unit or an appropriate bed for further monitoring and possible intervention. Serial ECGs and troponins are repeated over the next hours because a single normal set does not exclude an evolving infarction; a rising troponin, recurrent ST deviation, ventricular tachycardia, hemodynamic instability or heart failure would move the patient to the early invasive pathway.

Sources: AHA 2025 Adult ACLS Algorithms; ACC/AHA ACS Guideline (2025)

Question 5 · Post-Cardiac Arrest Care

A comatose patient is ventilated after ROSC, and the rate has been set to keep the ETCO₂ near 38 mm Hg. Data are: ETCO₂ 37 mm Hg, pH 7.29, PaCO₂ 54 mm Hg, PaO₂ 88 mm Hg, MAP 70 mm Hg. Which action is MOST appropriate?

  1. Give sodium bicarbonate to correct the pH of 7.29
  2. Leave the settings unchanged because the ETCO₂ is in normal range
  3. Allow the PaCO₂ of 54 to stand to increase cerebral blood flow
  4. Increase minute ventilation to bring PaCO₂ to 35 to 45
Show the answer and rationale

Answer: D

  • A. Tempting because the pH is low, but the acidemia here is respiratory: a PaCO₂ of 54 alone accounts for a pH near 7.29, so the fix is more ventilation rather than buffer.
  • B. Tempting because the ETCO₂ looks normal, but after cardiac arrest end-tidal CO₂ can read falsely low and may not reflect the PaCO₂.
  • C. Tempting because CO₂ dilates cerebral vessels, but mild hypercapnia did not improve neurologic outcome in the TAME trial, and it can raise intracranial pressure.
  • D. Correct. The arterial value, not the end-tidal value, shows hypercapnia, and normocapnia is the class 1 target in comatose patients.

End-tidal CO₂ is easy to trend, but after cardiac arrest it can read falsely low and fail to reflect the arterial value, so the AHA suggests a blood gas to assess PaCO₂ in ventilated patients (class 2b). It recommends keeping PaCO₂ within a normal range of about 35 to 45 mm Hg in patients who remain comatose (class 1), because hypercapnia dilates cerebral vessels and can raise intracranial pressure. Here the arterial value reveals hypoventilation and a respiratory acidemia that the end-tidal number concealed, so minute ventilation is increased.

Sources: AHA 2025 Part 11: Post-Cardiac Arrest Care; AHA 2025 Adult ACLS Algorithms

Question 6 · Special Situations (LVAD/Peds)

Megacode: A 7-year-old in cardiac arrest has VF on the monitor, and CPR is in progress. What is the recommended FIRST defibrillation energy?

  1. 10 J/kg
  2. Adult dose of 120–200 J
  3. 4 J/kg
  4. 2 J/kg
Show the answer and rationale

Answer: D

  • A. 10 J/kg is the maximum limit, not the first dose.
  • B. Pediatric defibrillation is weight-based until adult energy levels are reached.
  • C. 4 J/kg is the second-shock dose.
  • D. Correct. The first shock is 2 J/kg, then 4 J/kg, then 4 J/kg or more (maximum 10 J/kg or the adult dose).

The Pediatric Cardiac Arrest Algorithm recommends a first shock of 2 J/kg, a second shock of 4 J/kg, and subsequent shocks of 4 J/kg or more, not to exceed 10 J/kg or the standard adult dose. Pediatric pads or attenuators are used for young children when available. For children about 25 kg or more (roughly 8 years and older), adult pads and doses are generally appropriate.

Sources: AHA/AAP 2025 Part 8: PALS; AHA PALS Provider Manual (2025)

Question 7 · Basic Life Support (BLS)

In a hospital cafeteria, a 58-year-old man suddenly stands and grabs his neck. He cannot answer when asked whether he is choking, his attempts to cough are silent, and his lips are turning dusky. After calling for help, which sequence should the nurse use?

  1. Cycles of 5 back blows followed by 5 abdominal thrusts
  2. Abdominal thrusts repeated until the object is expelled
  3. Cycles of 5 back blows followed by 5 chest thrusts
  4. Lowering him to the floor and starting chest compressions
Show the answer and rationale

Answer: A

  • A. Correct. The 2025 guideline recommends repeated cycles of 5 back blows and 5 abdominal thrusts for severe obstruction in a responsive adult.
  • B. Abdominal thrusts alone were the earlier adult approach; back blows were added in 2025 because they relieved obstruction with fewer injuries in a cohort study.
  • C. Chest thrusts replace abdominal thrusts in late pregnancy or when the rescuer cannot encircle the abdomen, which is not the case here.
  • D. Compressions begin once the patient becomes unresponsive; while he is conscious, back blows and thrusts are used.

Inability to speak, a silent or absent cough, and cyanosis signal a severe foreign-body airway obstruction, which can progress quickly to unconsciousness and cardiac arrest. Because a cohort of 709 patients linked back blows to better relief and fewer injuries than abdominal thrusts, and thrusts have caused injuries such as gastric rupture, the 2025 AHA guideline adopts alternating sets of 5 back blows and 5 abdominal thrusts, matching the pediatric approach. Cycles continue until the object is expelled or the patient becomes unresponsive.

Sources: AHA 2025 Part 7: Adult BLS

Question 8 · Rhythm Recognition

A 74-year-old with hypertension and diabetes has had atrial fibrillation since palpitations began 10 days ago. He takes no anticoagulant. After IV metoprolol, he is stable with a ventricular rate of 88/min. The team wants to restore sinus rhythm with elective cardioversion. Which plan is MOST appropriate?

  1. Give heparin at the time of the shock and stop it the next day
  2. Cardiovert today, since the ventricular rate is now controlled
  3. Anticoagulate for 3 weeks, or image to exclude thrombus, first
  4. Use IV amiodarone instead, as drug conversion avoids embolism
Show the answer and rationale

Answer: C

  • A. Anticoagulation must continue uninterrupted for at least 4 weeks after cardioversion, because atrial stunning and a transient prothrombotic state follow the return to sinus rhythm.
  • B. Rate control does not remove a thrombus that may have formed during 10 days of AF, so converting now risks a stroke.
  • C. Correct. For AF lasting 48 hours or longer, 3 weeks of uninterrupted anticoagulation or imaging to exclude intracardiac thrombus is recommended before elective cardioversion.
  • D. Thromboembolic risk and the anticoagulation rules apply to pharmacological cardioversion as well as electrical cardioversion.

Thrombus can form in the left atrial appendage within 48 hours of AF onset, and restoring sinus rhythm by any method can dislodge it. The 2023 ACC/AHA/ACCP/HRS guideline therefore recommends, for AF of 48 hours or longer, either 3 weeks of uninterrupted therapeutic anticoagulation or imaging such as TEE to exclude thrombus before elective cardioversion. Anticoagulation then continues for at least 4 weeks afterward, because atrial stunning delays the return of mechanical atrial contraction. Long-term anticoagulation is decided separately from the stroke risk score, which here includes age, hypertension and diabetes.

Sources: ACC/AHA/ACCP/HRS AF Guideline (2023); AHA 2025 Part 9: Adult ALS

Question 9 · ACLS Pharmacology

A patient found with pinpoint pupils, RR 4, cyanosis, and a weak pulse of 52 has a used syringe nearby. According to the opioid-associated emergency algorithm, what is the IMMEDIATE management?

  1. Intubate before any other intervention
  2. Start chest compressions at 100–120/min
  3. Give epinephrine 1 mg IV push
  4. Bag-mask ventilate and give naloxone
Show the answer and rationale

Answer: D

  • A. Bag-mask ventilation and naloxone come first, and intubation may become unnecessary.
  • B. The patient has a pulse. The priority is ventilation.
  • C. Arrest-dose epinephrine is not indicated in a patient with a pulse.
  • D. Correct. Supporting ventilation and giving naloxone (IV, IM, or IN) reverses the opioid effect.

For opioid-associated respiratory arrest with a pulse, the priorities are to open the airway, provide bag-mask ventilation, and give naloxone (for example, 0.04–0.4 mg IV titrated, or 2–4 mg IN, repeated as needed). If there is no pulse, standard CPR takes priority, and naloxone may be given without delaying compressions. Patients need observation for renarcotization, especially with long-acting opioids.

Sources: AHA ACLS Provider Manual (2025); AHA 2025 Part 10: Special Circumstances

Question 10 · ACLS Algorithms

An 84-year-old taking digoxin for atrial fibrillation has had 3 days of nausea and yellow-tinged vision. Data are: HR 34 with complete heart block, BP 78/44, potassium 5.9 mEq/L, creatinine 2.6 mg/dL, digoxin level 4.2 ng/mL. Atropine 1 mg IV given twice has not changed the rate. What is the MOST appropriate next therapy?

  1. Atropine 1 mg IV, repeated to a total of 3 mg
  2. Digoxin immune Fab, with close potassium checks afterward
  3. Transvenous pacing until the digoxin is cleared
  4. Insulin and dextrose to lower the potassium
Show the answer and rationale

Answer: B

  • A. The algorithm allows atropine up to 3 mg, and the toxicology guidance rates atropine for digoxin bradycardia as weak (Class 2b); two doses have failed, and more atropine delays the antidote.
  • B. Correct. The AHA toxicology guidance recommends digoxin-specific antibody fragments for digoxin poisoning (Class 1), and the label lists heart block not responsive to atropine and potassium above 5.5 mEq/L among its indications.
  • C. Pacing may be reasonable as a bridge (Class 2b), and the poor kidney function makes waiting for clearance tempting, but pacing does not reverse the toxicity, which Fab treats directly.
  • D. Hyperkalemia here reflects digoxin poisoning of the sodium-potassium pump and marks its severity. Shifting potassium does not reverse the heart block, while Fab treats both the block and the hyperkalemia.

The 2025 bradycardia algorithm lists drugs such as digoxin among the causes to identify and treat. The 2023 AHA focused update on poisoning recommends digoxin-specific antibody fragments (Fab) for digoxin poisoning, and rates atropine and pacing for digoxin-induced bradycardia only as may-be-reasonable bridges. The DigiFab label lists progressive bradycardia, second- or third-degree block not responsive to atropine, and potassium above 5.5 mEq/L in adults as signs of life-threatening toxicity. After Fab, potassium can fall quickly, and total digoxin levels become misleading because they include bound drug.

Sources: AHA Focused Update: Poisoning (2023); FDA Prescribing Information (DailyMed); AHA 2025 Adult ACLS Algorithms

Question 11 · Post-Cardiac Arrest Care

A patient remains comatose after ROSC from an in-hospital cardiac arrest. Which temperature management plan is MOST consistent with the current AHA recommendations?

  1. Rapid prehospital cooling with 2 L of cold IV saline
  2. Cool to 30–32°C for 48 hours for maximum neuroprotection
  3. A steady 32–37.5°C target, then prevent fever
  4. Treat fever only if it exceeds 39°C, with no set target
Show the answer and rationale

Answer: C

  • A. Routine prehospital cold IV fluids are not recommended. They increased pulmonary edema and re-arrest without benefit.
  • B. Temperatures below 32°C increase arrhythmias, coagulopathy, and infection without proven benefit.
  • C. Correct. The AHA (2025) recommends deliberate temperature control at a constant target between 32 and 37.5°C for at least 36 hours, then fever prevention.
  • D. Deliberate temperature control with active fever prevention is recommended, not reactive treatment.

After the TTM2 trial, the AHA (2025) recommends deliberate temperature control for comatose post-arrest patients, selecting and maintaining a constant temperature between 32 and 37.5°C for at least 36 hours, rewarming no faster than 0.5°C per hour, and then preventing fever. Nursing considerations include managing shivering, electrolyte shifts during cooling and rewarming, glucose changes, bradycardia, and skin and device-related injury.

Sources: AHA 2025 Part 11: Post-Cardiac Arrest Care; AHA ACLS Provider Manual (2025)

Question 12 · Special Situations (LVAD/Peds)

An LVAD patient is found unresponsive, and the pump hum is faint. Which assessment findings indicate that perfusion is inadequate and chest compressions should begin?

  1. An absent radial pulse and no SpO₂ reading
  2. A Doppler MAP below 50 and ETCO₂ below 20
  3. Asystole on the monitor with audible pump hum
  4. A flat arterial waveform with a MAP of 72
Show the answer and rationale

Answer: B

  • A. These are common in well-perfused continuous-flow LVAD patients and do not define arrest.
  • B. Correct. These thresholds, along with unresponsiveness, indicate inadequate perfusion that warrants compressions.
  • C. LVAD patients can remain perfused in asystole or VF while the pump runs.
  • D. A MAP of 72 indicates adequate perfusion despite the flat waveform.

The AHA algorithm for LVAD patients who are unresponsive focuses on perfusion rather than pulses or rhythm. The team supports ventilation and assesses perfusion. Perfusion is adequate if any one of these is present: normal skin color and temperature, normal capillary refill, a MAP above 50 mm Hg (by Doppler or arterial line if the cuff fails), or an ETCO₂ above 20 mm Hg. An unresponsive patient with none of these, such as a Doppler MAP of 50 or less, an ETCO₂ of 20 or less, and cool, mottled skin, has impaired perfusion and gets compressions at once, while a second rescuer listens for the hum and checks alarms, the driveline, power, and the controller (AHA 2025, Part 10).

Sources: AACN Procedure Manual, 8th ed.; AHA 2025 Part 10: Special Circumstances

Question 13 · Basic Life Support (BLS)

An adult who choked on meat is now unresponsive, and the nurse is performing CPR. After 30 compressions, the nurse opens the airway with a head tilt–chin lift and sees nothing in the mouth. What should the nurse do NEXT?

  1. Attempt 2 breaths without a finger sweep
  2. Sweep the back of the throat with a hooked finger to find the meat
  3. Give 5 abdominal thrusts before trying to ventilate
  4. Skip breaths and keep compressing until the meat comes into view
Show the answer and rationale

Answer: A

  • A. Correct. A visible object is removed when the airway is opened for breaths; when none is seen, breaths are attempted and blind sweeps are avoided.
  • B. Blind finger sweeps are classed as harmful in the 2025 guideline because they can push the object deeper and worsen the obstruction.
  • C. Abdominal thrusts are not used once the patient is unresponsive; compressions provide the pressure to move the object.
  • D. Compressions can dislodge the object, but breaths are still attempted; there is no evidence they worsen the obstruction.

During CPR for an unresponsive choking adult, the rescuer looks in the mouth each time the airway is opened for breaths and removes any object that can be seen, which helps prevent reobstruction. Observational data show the risk of a blind finger sweep outweighs any benefit, so the guideline lists it as a class 3 harm. Breaths are still attempted: there is no evidence they worsen the obstruction, and in theory they could move a complete obstruction into a mainstem bronchus and allow some ventilation, and compressions then continue.

Sources: AHA 2025 Part 7: Adult BLS

Question 14 · Rhythm Recognition

VF has been seen at three consecutive rhythm checks after shocks at the defibrillator's maximum energy, with high-quality CPR, epinephrine and amiodarone. A team member notices that the anterior pad was placed over dense chest hair, its lower edge has lifted, and the patient's skin is wet with sweat. Which step is MOST appropriate before the next shock?

  1. Clip the hair, dry the skin and apply a fresh set of pads
  2. Move a second set of pads to an anteroposterior position
  3. Add a second defibrillator for double sequential shocks
  4. Deliver three stacked shocks at the next rhythm check
Show the answer and rationale

Answer: A

  • A. Correct. High impedance at the skin-pad interface is a correctable cause of shock failure, and the 2025 guideline advises fixing technique before alternate shock strategies.
  • B. Vector change may be considered for persisting VF, but its usefulness is not established, and it leaves the poorly attached anterior pad still limiting the current.
  • C. Double sequential defibrillation is rated as not established, needs millisecond timing that manual activation rarely achieves, and should follow correction of basic technique.
  • D. Stacked shocks lengthen the pause in compressions, and each one still passes through the same high-resistance pad contact.

Shock success depends on more than the energy setting. The 2025 AHA guideline notes that tissue resistance, which is typically highest at the skin-pad interface, can dramatically reduce current delivery, and that true shock failure is often due to correctable deficiencies in technique that are best addressed before pad repositioning or double sequential defibrillation. Hair, sweat and a lifting pad edge all raise impedance. The guideline also proposes the term persisting VF after three or more shocks, because about 80% of VF seen at rhythm checks is recurrence after a successful shock rather than shock failure; an antiarrhythmic and short pauses matter for that group.

Sources: AHA 2025 Part 9: Adult ALS

Question 15 · ACLS Pharmacology

Megacode: During refractory VF, the team leader chooses lidocaine instead of amiodarone. Which dosing is correct?

  1. 1–1.5 mg/kg, then 0.5–0.75 mg/kg
  2. 300 mg IV bolus, then 150 mg IV
  3. 0.5 mg/kg IV, then 0.25 mg/kg IV
  4. 5 mg/kg IV, then 2.5 mg/kg IV
Show the answer and rationale

Answer: A

  • A. Correct. Lidocaine is 1–1.5 mg/kg IV or IO first, then 0.5–0.75 mg/kg.
  • B. These are amiodarone doses.
  • C. These doses are too low.
  • D. These doses are excessive and risk toxicity.

Lidocaine and amiodarone are both acceptable antiarrhythmics for shock-refractory VF/pVT, with similar survival to admission and no proven difference in survival to discharge. Lidocaine is a class IB sodium channel blocker. Toxicity (CNS effects, seizures) is a concern with repeated doses, in liver disease, and in low-output states. After ROSC, a maintenance infusion may be considered.

Sources: AHA 2025 Adult ACLS Algorithms; AHA 2025 Part 9: Adult ALS

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