BLS — Basic Life Support — All Questions

What is the first link in the 2025 Chain of Survival?

• a.Post-cardiac-arrest care
• b.Advanced resuscitation
• c.Recognition and activation✓
• d.Defibrillation

The 2025 single six-link Chain of Survival begins with recognition and emergency activation; prevention and preparedness sit outside the chain.

How many Chains of Survival do the 2025 AHA Guidelines use for adult and pediatric, in- and out-of-hospital arrest?

• a.Four separate chains
• b.One six-link chain✓
• c.Two chains, by setting
• d.Two chains, by age

The 2025 Guidelines consolidated the four chains introduced in 2020 into a single six-link Chain of Survival that applies to all cardiac arrests.

Why is early defibrillation such a critical link in the Chain of Survival for a shockable rhythm?

• a.It matters only in hospitals
• b.Each minute of delay lowers survival✓
• c.It replaces chest compressions
• d.It helps only after 20 minutes

Registry data cited in the 2025 Guidelines show first-shock success falling from 93% within 6 minutes to 75% after 16 minutes, with about a 6% decrease in the probability of survival for each minute of delay.

How many links are in the 2025 Chain of Survival?

• a.Six✓
• b.Five
• c.Four
• d.Seven

The 2025 Guidelines consolidated the four 2020 chains into a single six-link Chain of Survival for all cardiac arrests.

Which is the first link of the 2025 Chain of Survival?

• a.Recognition and emergency activation✓
• b.Prevention and preparedness
• c.Post–cardiac arrest care
• d.Recovery

The chain begins with recognition and emergency activation; prevention and preparedness is named as the missing link, outside the 2025 chain.

Which link was added to the Chain of Survival in 2020 and kept in 2025?

• a.Advanced resuscitation
• b.Defibrillation
• c.Recovery✓
• d.High-quality CPR

The Systems of Care chapter records that a link representing recovery was added in 2020; recovery remains the sixth link in 2025.

What change was made to the CPR link symbol in the 2025 Chain of Survival?

• a.It now shows a hospital bed
• b.It adds breaths (lungs)✓
• c.It now shows only an AED
• d.It was removed from the chain

The symbol for high-quality CPR now shows compressions and breaths, represented by lungs, recognizing breathing's importance in pediatric arrests and adult arrests from drowning or opioids.

Which in-hospital systems do the 2025 Guidelines recommend to prevent cardiac arrest?

• a.Removing monitors from wards
• b.Daily defibrillator shocks
• c.Early warning systems and rapid response teams✓
• d.Routine mechanical CPR devices

The Guidelines recommend both early warning systems and rapid response teams to prevent in-hospital arrest, and safety huddles for high-risk patients.

A lay rescuer finds an adult who does not respond and is breathing only in occasional gasps. What does this mean?

• a.Place the person on their side and wait
• b.Treat it as arrest; start CPR✓
• c.Check the pulse for a full minute
• d.The person is breathing adequately

Lay rescuers recognize arrest by unresponsiveness and absent or abnormal breathing; gasping is agonal breathing, which is ineffective for ventilation.

What did survival to hospital discharge look like for adult EMS-treated out-of-hospital arrest in the registry data cited in 2025?

• a.About 50%
• b.About 10.5%✓
• c.About 1%
• d.About 90%

The 2025 executive summary reports survival to hospital discharge of 10.5% after EMS-treated adult out-of-hospital arrest, underscoring the value of early CPR and defibrillation.

Which term do the 2025 Guidelines prefer for a person without medical training who helps?

• a.Civilian responder
• b.Layperson
• c.Bystander
• d.Lay rescuer✓

"Lay rescuer" is favored over "bystander" because it encourages action rather than implying someone who is merely present.

A telecommunicator suspects cardiac arrest from a caller's answers. What instructions does the 2025 evidence most strongly support for an adult?

• a.Breaths only until EMS arrives
• b.Waiting silently on the line
• c.Moving the patient to a car
• d.Compression-only instructions✓

The level of evidence for telecommunicator compression-only instructions in adult out-of-hospital arrest was raised to LOE A in 2025.

What is the first thing a telecommunicator should obtain on a 911 call for a possible arrest?

• a.The patient's medical history
• b.The caller's location✓
• c.The patient's insurance details
• d.The caller's CPR certification

Obtaining location information first lets the appropriate emergency response be dispatched even if the call is disconnected while CPR instructions are given.

For a lone adult rescuer with a mobile phone, what is the recommended order?

• a.Find an AED before calling anyone
• b.Give 5 minutes of CPR, then call
• c.Call EMS and wait for them without CPR
• d.Call first, then CPR at once✓

A lone responder should activate the emergency response system first and then immediately begin CPR; a phone's speaker allows near-simultaneous activation and compressions.

What is the risk of giving compressions to an unresponsive adult who turns out not to be in cardiac arrest?

• a.It stops a beating heart
• b.Low compared with the benefit✓
• c.High, so rescuers should wait
• d.It always causes fatal injury

The Guidelines state the benefit of CPR for someone in arrest far outweighs any risk of compressions for someone who is not, and serious harm has not been associated with it.

In the 2025 Guidelines, who can give naloxone for suspected opioid overdose?

• a.Pharmacists only
• b.Paramedics only
• c.Physicians only
• d.Anyone, including the public✓

The 2025 executive summary states that trained rescuers, lay rescuers and members of the general public can all administer naloxone.

A lay rescuer finds an unresponsive adult who is not breathing normally after a suspected opioid overdose. What should be done?

• a.Compressions only, never breaths
• b.CPR with breaths; naloxone✓
• c.Recovery position and observation
• d.Naloxone only, then wait

For lay rescuers assisting an unresponsive person not breathing normally after suspected opioid overdose, CPR with breaths should be provided; naloxone may be given without interrupting CPR.

Why is the uterus displaced to the left during CPR on a patient in late pregnancy?

• a.To reduce the need for breaths
• b.To ease pressure on the vena cava and aorta✓
• c.To make room for the AED pads
• d.To speed up the delivery

Manual left lateral uterine displacement relieves compression of the inferior vena cava and aorta to allow better cardiac output when the fundal height is at or above the umbilicus.

A person pulled from cold water is in cardiac arrest and feels icy. What do the 2025 Guidelines say?

• a.Cold patients should not receive CPR
• b.Stop CPR once the skin feels cold
• c.Resuscitate while rewarming✓
• d.Rewarm fully before any CPR

Adults and children with life-threatening hypothermia may survive with good neurological outcomes even after prolonged arrest, and should be rewarmed during resuscitation.

Why do drowning victims especially need breaths during CPR?

• a.Breaths remove water from the lungs
• b.Hypoxia usually causes the arrest✓
• c.Drowning victims cannot receive compressions
• d.AEDs never work after drowning

Drowning usually progresses from hypoxic respiratory arrest to cardiac arrest, and outcomes are better when CPR includes breaths.