ACLS — Advanced Cardiovascular Life Support — All Questions

What is the recommended chest compression rate for high-quality CPR in an adult?

• a.60 to 80 compressions per minute
• b.80 to 100 compressions per minute
• c.100 to 120 compressions per minute✓
• d.120 to 140 compressions per minute

Current AHA guidelines call for a compression rate of 100 to 120 per minute. Rates slower than 100 reduce coronary and cerebral perfusion, while rates faster than 120 shorten the recoil/filling phase and reduce the depth actually achieved, so the diastolic filling of the heart suffers. Staying inside the 100-120 window balances forward blood flow with adequate ventricular filling.

What is the correct chest compression depth for an average adult?

• a.At least 1 inch (2.5 cm)
• b.At least 1.5 inches (4 cm)
• c.At least 2 inches (5 cm) but not more than 2.4 inches (6 cm)✓
• d.At least 3 inches (7.5 cm)

For an adult, compress at least 2 inches (5 cm) but avoid exceeding 2.4 inches (6 cm). Compressions that are too shallow fail to generate adequate blood flow; excessive depth beyond 6 cm has been associated with injury. Equally important, allow full chest recoil between compressions so the heart can refill.

To maximize the chest compression fraction, interruptions in compressions should be limited to less than:

• a.5 seconds
• b.10 seconds✓
• c.20 seconds
• d.30 seconds

Pauses in compressions (for rhythm checks, ventilation, or defibrillation) should be kept under 10 seconds. The goal is a chest compression fraction of at least 60%. Every second without compressions drops coronary perfusion pressure, which then takes several compressions to rebuild, so minimizing hands-off time directly improves the odds of ROSC.

Once an advanced airway (e.g., endotracheal tube) is in place during cardiac arrest, how should ventilations be delivered?

• a.Pause compressions and give 30:2 cycles
• b.Give 1 breath every 6 seconds (10 breaths/min) with continuous compressions✓
• c.Give 1 breath every 3 seconds with continuous compressions
• d.Give 20 breaths per minute synchronized to compressions

With an advanced airway, rescuers no longer pause for ventilation. Compressions become continuous at 100-120/min while one breath is delivered every 6 seconds (10 breaths/min). This asynchronous approach maintains a high compression fraction and avoids the harmful hyperventilation that raises intrathoracic pressure and reduces venous return.

What is the most reliable method to confirm and continuously monitor correct endotracheal tube placement during CPR?

• a.Auscultation of breath sounds alone
• b.Continuous quantitative waveform capnography✓
• c.Chest x-ray obtained after the code
• d.Pulse oximetry readings

Continuous quantitative waveform capnography is the recommended standard for confirming and monitoring ET tube placement. It verifies the tube is in the trachea (a sustained CO2 waveform), detects dislodgement in real time, and gauges CPR quality — a sudden abrupt rise in ETCO2 often signals return of spontaneous circulation. Auscultation and oximetry are adjuncts, and a chest x-ray is too slow to guide the resuscitation.

During bag-mask ventilation, delivering breaths too rapidly and forcefully is harmful mainly because it:

• a.Cools the patient too quickly
• b.Increases intrathoracic pressure, which reduces venous return and cardiac output✓
• c.Improves oxygenation beyond what is needed
• d.Has no measurable effect on the resuscitation

Excessive ventilation raises intrathoracic pressure, which impedes venous return to the chest and lowers cardiac output and coronary perfusion during CPR. It can also cause gastric inflation and aspiration. Deliver each breath over about 1 second with just enough volume to produce visible chest rise, and avoid over-ventilating.

What is the correct dose and interval of epinephrine during adult cardiac arrest?

• a.0.5 mg IV/IO every 10 minutes
• b.1 mg IV/IO every 3 to 5 minutes✓
• c.3 mg IV/IO given once
• d.1 mg IV/IO every minute

Epinephrine in cardiac arrest is 1 mg IV/IO every 3 to 5 minutes. Its alpha-adrenergic vasoconstriction raises aortic diastolic pressure and thereby coronary perfusion pressure. In non-shockable rhythms (asystole/PEA), give epinephrine as soon as feasible; in shockable rhythms (VF/pVT), give it after the first shock or two fail to convert the rhythm.

For refractory ventricular fibrillation or pulseless VT, what is the first dose of amiodarone?

• a.150 mg IV/IO bolus
• b.300 mg IV/IO bolus✓
• c.1 mg IV/IO bolus
• d.6 mg IV/IO bolus

The first amiodarone dose for shock-refractory VF/pVT is 300 mg IV/IO push, followed by a second dose of 150 mg if needed. Amiodarone is an antiarrhythmic given after epinephrine and continued defibrillation attempts have not converted the rhythm. Lidocaine (1-1.5 mg/kg first dose) is an acceptable alternative.

A stable patient has a regular narrow-complex SVT and vagal maneuvers have failed. What is the first dose of adenosine?

• a.6 mg rapid IV push, followed by a 12 mg dose if needed✓
• b.1 mg slow IV push
• c.0.5 mg IV push
• d.300 mg IV bolus

Adenosine is given 6 mg by rapid IV push (followed immediately by a saline flush), and if the rhythm does not convert, a 12 mg dose may follow. Its very short half-life briefly blocks AV nodal conduction, which can terminate a re-entrant SVT. It is used only for stable, regular, narrow-complex tachycardia after vagal maneuvers fail.

What is the atropine regimen for symptomatic bradycardia in adults?

• a.0.5 mg IV once, maximum 1 mg
• b.1 mg IV every 3 to 5 minutes, maximum total 3 mg✓
• c.3 mg IV given once
• d.6 mg rapid IV push

For symptomatic bradycardia, atropine is 1 mg IV every 3 to 5 minutes up to a maximum total dose of 3 mg. Atropine blocks vagal tone to increase heart rate. If it is ineffective, move to transcutaneous pacing or a dopamine or epinephrine infusion. (Note the atropine dose was updated to 1 mg in current guidelines, replacing the older 0.5 mg.)

Which pair of rhythms is treated with defibrillation (i.e., is 'shockable')?

• a.Asystole and pulseless electrical activity (PEA)
• b.Ventricular fibrillation and pulseless ventricular tachycardia✓
• c.Sinus bradycardia and first-degree AV block
• d.Normal sinus rhythm and atrial flutter with a pulse

Only ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) are shockable — defibrillation can reset the chaotic ventricular activity so an organized rhythm can resume. Asystole and PEA are non-shockable; they are treated with CPR, epinephrine, and correction of reversible causes. Delivering a shock to asystole or PEA provides no benefit.

The monitor shows a flat line, confirmed in two leads, in a pulseless patient. The correct action is to:

• a.Defibrillate immediately
• b.Perform synchronized cardioversion
• c.Continue high-quality CPR, give epinephrine, and treat reversible causes — do not shock✓
• d.Give adenosine 6 mg rapid IV push

A confirmed flat line is asystole, a non-shockable rhythm. Management is high-quality CPR, epinephrine 1 mg every 3-5 minutes, and an active search for the H's and T's (reversible causes). Confirming asystole in more than one lead rules out 'fine VF' or a lead/equipment problem masquerading as a flat line. Defibrillation and cardioversion have no role in asystole.

A stable patient has a regular narrow-complex tachycardia at 180 bpm; vagal maneuvers have not worked. The next appropriate step is:

• a.Defibrillate the patient
• b.Give adenosine 6 mg by rapid IV push✓
• c.Give atropine 1 mg IV
• d.Give epinephrine 1 mg IV push

A regular narrow-complex tachycardia that persists after vagal maneuvers in a stable patient is treated with adenosine 6 mg rapid IV push (then 12 mg if needed). This most likely represents a re-entrant SVT, and adenosine's transient AV nodal block can break the circuit. Defibrillation, atropine, and arrest-dose epinephrine are all inappropriate for a stable, perfusing SVT.

A patient collapses in witnessed VF arrest and a defibrillator is immediately available. The highest priority is to:

• a.Establish IV access and give epinephrine first
• b.Intubate the patient before anything else
• c.Deliver a defibrillation shock as soon as possible and then resume compressions✓
• d.Give amiodarone 300 mg before defibrillating

For VF/pVT, the single most important intervention is early defibrillation combined with high-quality CPR. When a defibrillator is at hand for a witnessed arrest, shock as soon as it is ready, then immediately resume compressions. Drugs and advanced airway are secondary and should not delay the first shock, because the chance of successful defibrillation falls with each passing minute in VF.

The monitor shows an organized rhythm but the patient has no pulse (PEA). Management includes:

• a.Immediate defibrillation
• b.High-quality CPR, epinephrine, and a search for reversible causes (H's and T's)✓
• c.Synchronized cardioversion
• d.Adenosine 6 mg rapid IV push

Pulseless electrical activity is non-shockable. The key to survival is identifying and correcting the underlying cause while giving high-quality CPR and epinephrine 1 mg every 3-5 minutes. The reversible causes are the H's (hypovolemia, hypoxia, hydrogen ion/acidosis, hypo-/hyperkalemia, hypothermia) and T's (tension pneumothorax, tamponade, toxins, thrombosis-pulmonary, thrombosis-coronary).

Immediately after delivering a defibrillation shock, the team should:

• a.Check a pulse for 30 seconds
• b.Resume chest compressions immediately and continue CPR for about 2 minutes✓
• c.Reanalyze the rhythm right away before touching the patient
• d.Deliver two rescue breaths before compressions

After a shock, resume compressions immediately without a pulse or rhythm check, and continue CPR for about 2 minutes before the next rhythm analysis. Even when a shock is successful, an organized rhythm and a palpable pulse often take time to appear, and pausing to check wastes critical perfusion time. Minimizing the post-shock pause is a cornerstone of high-quality resuscitation.

A patient has a heart rate of 38 with hypotension and altered mental status. What is the first-line drug?

• a.Adenosine 6 mg rapid IV push
• b.Atropine 1 mg IV✓
• c.Amiodarone 300 mg IV
• d.Epinephrine 1 mg IV push

This is symptomatic bradycardia, and atropine 1 mg IV (repeatable every 3-5 minutes to a maximum of 3 mg) is the first-line drug. Atropine reduces vagal tone to raise the rate. If atropine is ineffective, the next steps are transcutaneous pacing or an epinephrine or dopamine infusion. A 1 mg epinephrine push is the arrest dose and is not used for a perfusing bradycardia.

A patient with wide-complex tachycardia has a pulse but is hypotensive and confused. The appropriate treatment is:

• a.Unsynchronized defibrillation
• b.Synchronized cardioversion✓
• c.Adenosine only, then observe
• d.No treatment; continue to observe

An unstable tachycardia WITH a pulse (hypotension, altered mental status, ischemic chest pain, or signs of shock) is treated with immediate synchronized cardioversion. Synchronization times the shock to the R wave to avoid delivering energy during the vulnerable T-wave period, which could induce VF. Unsynchronized defibrillation is reserved for pulseless VT/VF.

Atropine has failed to improve a patient's symptomatic bradycardia. Appropriate next steps include:

• a.Defibrillate the patient
• b.Transcutaneous pacing or a dopamine/epinephrine infusion✓
• c.Give adenosine 6 mg rapid IV push
• d.Perform synchronized cardioversion

When atropine does not resolve symptomatic bradycardia, escalate to transcutaneous pacing and/or a dopamine or epinephrine infusion to support the rate and blood pressure while addressing the underlying cause. Defibrillation and cardioversion treat tachyarrhythmias, and adenosine slows the AV node — none are appropriate for a slow, poorly perfusing rhythm.

For a patient with a STEMI, the goal for first-medical-contact-to-device time with primary PCI is within:

• a.30 minutes
• b.90 minutes✓
• c.4 hours
• d.12 hours

For STEMI, the reperfusion goal for primary percutaneous coronary intervention (PCI) is a first-medical-contact-to-device time of 90 minutes or less. 'Time is muscle' — the sooner the occluded coronary artery is reopened, the more myocardium is salvaged. When timely PCI is unavailable, fibrinolytic therapy is targeted within 30 minutes of arrival (door-to-needle).

For a suspected acute ischemic stroke, the first critical imaging step to determine fibrinolytic eligibility is:

• a.MRI of the brain with contrast
• b.A noncontrast CT of the head to exclude hemorrhage✓
• c.Carotid ultrasound
• d.A chest x-ray

An emergent noncontrast head CT is obtained to rule out intracranial hemorrhage before any fibrinolytic is considered, because giving a clot-dissolving drug to a bleeding stroke is catastrophic. Alongside imaging, establishing the last-known-well time defines the treatment window. Rapid door-to-CT and door-to-treatment times are central to the AHA stroke chain of survival.

In a comatose patient after return of spontaneous circulation (ROSC), targeted temperature management involves maintaining a constant temperature between:

• a.32°C and 36°C (89.6°F to 96.8°F)✓
• b.38°C and 40°C (100.4°F to 104°F)
• c.28°C and 30°C (82.4°F to 86°F)
• d.An uncontrolled room temperature

For adults who remain comatose after ROSC, targeted temperature management (TTM) selects and maintains a constant target between 32°C and 36°C for at least 24 hours. Controlling temperature and preventing fever helps protect the brain from secondary injury. Post-arrest care also includes optimizing oxygenation and blood pressure and treating the precipitating cause (e.g., emergent PCI for a coronary occlusion).