AHA ACLS POST-TEST ANSWER KEY 2026/2027
EDITION AMERICAN HEART ASSOCIATION GUIDELINES
UPDATE 250 QUESTIONS AND ANSWERS WITH DETAILED
RATIONALES | MOST RECENT!!
SECTION 1: BASIC LIFE SUPPORT (BLS) AND CPR (Questions 1–25)
1. During a witnessed cardiac arrest in a monitored unit, the rhythm is initially
ventricular tachycardia (pulseless). A defibrillator is immediately available.
According to the 2026/2027 AHA guidelines, what is the optimal sequence of
actions for a single rescuer until additional help arrives?
A) Immediately start chest compressions, then analyze rhythm, then defibrillate,
then resume compressions.
B) Check pulse for up to 10 seconds, then defibrillate immediately, then start
chest compressions.
C) Verify unresponsiveness, activate emergency response, get defibrillator, then
analyze rhythm and defibrillate if shockable.
D) Start chest compressions at a rate of 100-120/min, then after 2 minutes
analyze rhythm, then defibrillate.
Answer: C
Rationale: The correct sequence for a witnessed arrest with immediate
defibrillator access is: verify unresponsiveness, activate emergency response,
retrieve defibrillator, then analyze rhythm and deliver shock if indicated. Starting
compressions before rhythm analysis delays defibrillation, which is critical for
shockable rhythms. Evidence shows that for witnessed VF/pulseless VT,
immediate defibrillation within 3–5 minutes significantly improves survival.
Options A and D delay defibrillation; option B wastes time with a pulse check in a
witnessed arrest.
2. A team is performing CPR on a patient with suspected opioid overdose. The
patient has a pulse but is not breathing adequately. What is the most appropriate
BLS intervention according to the 2026/2027 guidelines?
1
,A) Immediately begin chest compressions at a rate of 100-120/min until naloxone
is administered.
B) Provide rescue breaths at a rate of 1 breath every 5-6 seconds, reassess pulse
frequently.
C) Administer naloxone intramuscularly and then reassess breathing before
starting CPR.
D) Deliver two initial rescue breaths, then begin chest compressions if breathing
does not improve.
Answer: B
Rationale: For a patient with a pulse but inadequate breathing (respiratory
arrest), the appropriate BLS intervention is rescue breathing. The recommended
rate is 1 breath every 5–6 seconds (10–12 breaths/min) with frequent pulse
checks every 2 minutes. Chest compressions are not indicated when a pulse is
present. Naloxone may be given but should not delay ventilation, as hypoxic brain
damage occurs within 4–6 minutes. Options A and D include unnecessary
compressions; option C delays ventilation while waiting for naloxone.
3. In a cardiac arrest situation with an advanced airway in place, you are providing
continuous chest compressions at a rate of 110/min. What ventilation rate should
be delivered to optimize coronary perfusion pressure while avoiding
hyperventilation?
A) 6 breaths per minute (1 breath every 10 seconds)
B) 8-10 breaths per minute (1 breath every 6-8 seconds)
C) 12-15 breaths per minute (1 breath every 4-5 seconds)
D) 20 breaths per minute (1 breath every 3 seconds)
Answer: B
Rationale: With an advanced airway, continuous compressions are performed at
100–120/min, and ventilations are delivered at 8–10 breaths/min (1 breath every
6–8 seconds). This rate prevents hyperventilation, which increases intrathoracic
pressure, decreases venous return, and reduces coronary perfusion pressure.
Hyperventilation also causes respiratory alkalosis, leading to cerebral
vasoconstriction and decreased cerebral blood flow. Option A is too low; options
C and D risk hyperventilation.
2
,4. A 55-year-old male collapses suddenly in the hospital cafeteria. You are first on
the scene. What is the correct initial action according to the 2026/2027 AHA BLS
algorithm?
A) Begin chest compressions immediately
B) Check for carotid pulse for 10 seconds
C) Verify scene safety and check for responsiveness
D) Deliver two rescue breaths and check for a pulse
Answer: C
Rationale: The BLS algorithm begins with ensuring scene safety, followed by
checking responsiveness. This protects the rescuer from potential hazards
(electrical, chemical, or physical dangers) and confirms the patient is truly
unresponsive. After confirming unresponsiveness, activate the emergency
response system and get the AED/defibrillator. Checking breathing and pulse
occurs simultaneously within 10 seconds, but only after scene safety and
responsiveness are assessed.
5. After confirming unresponsiveness in an adult patient, what is the maximum
time recommended for checking breathing and pulse simultaneously?
A) 5 seconds
B) 10 seconds
C) 15 seconds
D) 20 seconds
Answer: B
Rationale: The 2026/2027 guidelines recommend checking for breathing and
pulse simultaneously for no more than 10 seconds. If the patient is not breathing
normally or has no pulse, CPR should be initiated immediately. Prolonged pulse
checks delay chest compressions and reduce the chance of ROSC. Studies show
that pulses are often misidentified, so a 10-second limit prevents unnecessary
delays.
6. What is the recommended compression depth for an adult during CPR
according to the 2026/2027 AHA guidelines?
3
, A) At least 2 inches (5 cm) but not more than 2.4 inches (6 cm)
B) At least 2.4 inches (6 cm) but not more than 3 inches (7.5 cm)
C) Exactly 2 inches (5 cm)
D) 1.5 to 2 inches (4 to 5 cm)
Answer: A
Rationale: The guidelines recommend a compression depth of at least 2 inches (5
cm) and no more than 2.4 inches (6 cm). This range ensures adequate myocardial
perfusion while minimizing the risk of injury from excessive depth. Deeper than
2.4 inches increases complications; shallower than 2 inches reduces coronary
perfusion pressure and survival.
7. When performing two-rescuer adult CPR, what is the correct compression-to-
ventilation ratio without an advanced airway?
A) 30:2
B) 15:2
C) 20:2
D) 30:1
Answer: A
Rationale: For adult CPR without an advanced airway, the ratio is 30:2 for both
single and two-rescuer CPR. This ratio maximizes the number of compressions
while providing adequate ventilation. The previous 15:2 ratio for two-rescuer was
eliminated to simplify training and ensure more compressions per minute.
8. A child (age 6) is in cardiac arrest. Two rescuers are present, and there is no
advanced airway. What is the recommended compression-to-ventilation ratio?
A) 30:2
B) 15:2
C) 20:2
D) 30:1
Answer: B
Rationale: For pediatric CPR (infants and children up to puberty) with two
rescuers, the ratio is 15:2. For a single rescuer, it is 30:2. This difference allows for
more ventilations in children, where respiratory causes of arrest are more
4
EDITION AMERICAN HEART ASSOCIATION GUIDELINES
UPDATE 250 QUESTIONS AND ANSWERS WITH DETAILED
RATIONALES | MOST RECENT!!
SECTION 1: BASIC LIFE SUPPORT (BLS) AND CPR (Questions 1–25)
1. During a witnessed cardiac arrest in a monitored unit, the rhythm is initially
ventricular tachycardia (pulseless). A defibrillator is immediately available.
According to the 2026/2027 AHA guidelines, what is the optimal sequence of
actions for a single rescuer until additional help arrives?
A) Immediately start chest compressions, then analyze rhythm, then defibrillate,
then resume compressions.
B) Check pulse for up to 10 seconds, then defibrillate immediately, then start
chest compressions.
C) Verify unresponsiveness, activate emergency response, get defibrillator, then
analyze rhythm and defibrillate if shockable.
D) Start chest compressions at a rate of 100-120/min, then after 2 minutes
analyze rhythm, then defibrillate.
Answer: C
Rationale: The correct sequence for a witnessed arrest with immediate
defibrillator access is: verify unresponsiveness, activate emergency response,
retrieve defibrillator, then analyze rhythm and deliver shock if indicated. Starting
compressions before rhythm analysis delays defibrillation, which is critical for
shockable rhythms. Evidence shows that for witnessed VF/pulseless VT,
immediate defibrillation within 3–5 minutes significantly improves survival.
Options A and D delay defibrillation; option B wastes time with a pulse check in a
witnessed arrest.
2. A team is performing CPR on a patient with suspected opioid overdose. The
patient has a pulse but is not breathing adequately. What is the most appropriate
BLS intervention according to the 2026/2027 guidelines?
1
,A) Immediately begin chest compressions at a rate of 100-120/min until naloxone
is administered.
B) Provide rescue breaths at a rate of 1 breath every 5-6 seconds, reassess pulse
frequently.
C) Administer naloxone intramuscularly and then reassess breathing before
starting CPR.
D) Deliver two initial rescue breaths, then begin chest compressions if breathing
does not improve.
Answer: B
Rationale: For a patient with a pulse but inadequate breathing (respiratory
arrest), the appropriate BLS intervention is rescue breathing. The recommended
rate is 1 breath every 5–6 seconds (10–12 breaths/min) with frequent pulse
checks every 2 minutes. Chest compressions are not indicated when a pulse is
present. Naloxone may be given but should not delay ventilation, as hypoxic brain
damage occurs within 4–6 minutes. Options A and D include unnecessary
compressions; option C delays ventilation while waiting for naloxone.
3. In a cardiac arrest situation with an advanced airway in place, you are providing
continuous chest compressions at a rate of 110/min. What ventilation rate should
be delivered to optimize coronary perfusion pressure while avoiding
hyperventilation?
A) 6 breaths per minute (1 breath every 10 seconds)
B) 8-10 breaths per minute (1 breath every 6-8 seconds)
C) 12-15 breaths per minute (1 breath every 4-5 seconds)
D) 20 breaths per minute (1 breath every 3 seconds)
Answer: B
Rationale: With an advanced airway, continuous compressions are performed at
100–120/min, and ventilations are delivered at 8–10 breaths/min (1 breath every
6–8 seconds). This rate prevents hyperventilation, which increases intrathoracic
pressure, decreases venous return, and reduces coronary perfusion pressure.
Hyperventilation also causes respiratory alkalosis, leading to cerebral
vasoconstriction and decreased cerebral blood flow. Option A is too low; options
C and D risk hyperventilation.
2
,4. A 55-year-old male collapses suddenly in the hospital cafeteria. You are first on
the scene. What is the correct initial action according to the 2026/2027 AHA BLS
algorithm?
A) Begin chest compressions immediately
B) Check for carotid pulse for 10 seconds
C) Verify scene safety and check for responsiveness
D) Deliver two rescue breaths and check for a pulse
Answer: C
Rationale: The BLS algorithm begins with ensuring scene safety, followed by
checking responsiveness. This protects the rescuer from potential hazards
(electrical, chemical, or physical dangers) and confirms the patient is truly
unresponsive. After confirming unresponsiveness, activate the emergency
response system and get the AED/defibrillator. Checking breathing and pulse
occurs simultaneously within 10 seconds, but only after scene safety and
responsiveness are assessed.
5. After confirming unresponsiveness in an adult patient, what is the maximum
time recommended for checking breathing and pulse simultaneously?
A) 5 seconds
B) 10 seconds
C) 15 seconds
D) 20 seconds
Answer: B
Rationale: The 2026/2027 guidelines recommend checking for breathing and
pulse simultaneously for no more than 10 seconds. If the patient is not breathing
normally or has no pulse, CPR should be initiated immediately. Prolonged pulse
checks delay chest compressions and reduce the chance of ROSC. Studies show
that pulses are often misidentified, so a 10-second limit prevents unnecessary
delays.
6. What is the recommended compression depth for an adult during CPR
according to the 2026/2027 AHA guidelines?
3
, A) At least 2 inches (5 cm) but not more than 2.4 inches (6 cm)
B) At least 2.4 inches (6 cm) but not more than 3 inches (7.5 cm)
C) Exactly 2 inches (5 cm)
D) 1.5 to 2 inches (4 to 5 cm)
Answer: A
Rationale: The guidelines recommend a compression depth of at least 2 inches (5
cm) and no more than 2.4 inches (6 cm). This range ensures adequate myocardial
perfusion while minimizing the risk of injury from excessive depth. Deeper than
2.4 inches increases complications; shallower than 2 inches reduces coronary
perfusion pressure and survival.
7. When performing two-rescuer adult CPR, what is the correct compression-to-
ventilation ratio without an advanced airway?
A) 30:2
B) 15:2
C) 20:2
D) 30:1
Answer: A
Rationale: For adult CPR without an advanced airway, the ratio is 30:2 for both
single and two-rescuer CPR. This ratio maximizes the number of compressions
while providing adequate ventilation. The previous 15:2 ratio for two-rescuer was
eliminated to simplify training and ensure more compressions per minute.
8. A child (age 6) is in cardiac arrest. Two rescuers are present, and there is no
advanced airway. What is the recommended compression-to-ventilation ratio?
A) 30:2
B) 15:2
C) 20:2
D) 30:1
Answer: B
Rationale: For pediatric CPR (infants and children up to puberty) with two
rescuers, the ratio is 15:2. For a single rescuer, it is 30:2. This difference allows for
more ventilations in children, where respiratory causes of arrest are more
4
