BLS — Basic Life Support — All Questions
21 questions
How should each breath be delivered during CPR?
- a.Over 5 seconds with maximum volume
- b.As forcefully and quickly as possible
- c.Over about 1 second, to chest rise✓
- d.Only through the nose
Each breath takes about 1 second with just enough volume for visible chest rise; excessive ventilation causes gastric inflation and lowers cardiac output. (2025 terminology uses 'breaths' rather than 'rescue breaths'.)
A single rescuer is performing CPR on an adult without an advanced airway. What compression-to-ventilation ratio is used?
- a.Continuous compressions with no breaths
- b.15 compressions to 2 breaths
- c.30 compressions to 2 breaths✓
- d.5 compressions to 1 breath
A lone rescuer uses a 30:2 ratio for adults, children, and infants. The 15:2 ratio applies only when two rescuers are caring for a child or infant. Once an advanced airway is in place, rescuers switch to continuous compressions with one breath every 6 seconds and stop pausing for breaths.
An adult has a pulse but is not breathing. What is the correct rescue-breathing rate?
- a.1 breath every 2 seconds (about 30 per minute)
- b.1 breath every 6 seconds (about 10 per minute)✓
- c.1 breath every 3 seconds (about 20 per minute)
- d.1 breath every 10 seconds (about 6 per minute)
When an adult has a pulse but inadequate breathing, give rescue breaths at 1 every 6 seconds, about 10 per minute, without chest compressions. Recheck the pulse roughly every 2 minutes. If the pulse is lost, begin CPR with compressions.
A child has a pulse but is not breathing adequately. What is the correct breathing rate?
- a.1 breath every 15 seconds
- b.1 breath every 10 seconds
- c.1 breath every 6 seconds
- d.1 breath every 2–3 seconds✓
For infants and children with a pulse and inadequate breathing, the 2025 Guidelines recommend 20 to 30 breaths per minute, taught as 1 breath every 2 to 3 seconds; every 6 seconds is the adult rate.
How long should each breath take during adult CPR?
- a.About 1 second✓
- b.About 3 seconds
- c.About 5 seconds
- d.As long as possible
A 1-second inspiratory time keeps pauses in compressions as short as possible during 30:2 CPR, with just enough volume for visible chest rise.
What signals that a breath has enough volume?
- a.The stomach swells
- b.The patient coughs
- c.Rescuer dizziness
- d.Visible chest rise✓
Rescuers are advised to deliver each breath until there is visible chest rise; stomach swelling signals excessive ventilation.
Which barrier device delivered more effective breaths than a face shield?
- a.A cloth mask
- b.A plastic bag
- c.No device at all
- d.A pocket mask✓
Breaths through a pocket mask were more effective than through a face shield, so a pocket mask should be used if available.
A person with a pulse is not breathing normally after an overdose. How often should an adult receive breaths?
- a.Every 15 seconds
- b.Every 2 seconds
- c.Every 6 seconds✓
- d.Every 30 seconds
For adults who have a pulse but are not breathing normally, the Guidelines say 1 breath every 6 seconds (10 per minute) is reasonable.
How often should breaths be given to a 1-year-old who has a pulse but inadequate breathing?
- a.Every 20 seconds
- b.Every 6 seconds
- c.Every 2 to 3 seconds✓
- d.Every 10 seconds
For infants and children with a pulse and inadequate breathing, the recommended rate is 1 breath every 2 to 3 seconds (20 to 30 per minute).
Which maneuver is preferred to open the airway of an unresponsive diver with a possible neck injury?
- a.Head tilt–chin lift
- b.Jaw thrust✓
- c.Blind finger sweep
- d.Neck flexion
With suspected head or neck trauma, trained rescuers use a jaw thrust, which moves the neck less; if it fails, a head tilt–chin lift is used because a patent airway takes priority.
Want these explained in order? ACLS & BLS Study Guide — 2026 Edition — PDF + EPUB, $24.99 · 14-day refund →
Why is cricoid pressure not routinely used during cardiac arrest?
- a.It has no proven benefit in arrest✓
- b.It causes the heart to stop
- c.It is used only by lay rescuers
- d.It is required only for children
There is no evidence that cricoid pressure facilitates ventilation or reduces aspiration in arrest, and it may interfere with air entry and advanced airway placement.
When is an oropharyngeal airway inappropriate?
- a.When bag-mask ventilation is planned
- b.When the patient is in cardiac arrest
- c.When the gag reflex is intact✓
- d.When the patient is unresponsive
The Guidelines note oropharyngeal airways are contraindicated with an intact gag reflex, while nasopharyngeal airways are avoided with suspected facial trauma.
What does excessive ventilation during CPR cause?
- a.Faster return of circulation
- b.Lower risk of aspiration
- c.Better oxygen delivery with no harm
- d.Gastric inflation, lower output✓
Excessive ventilation can cause gastric inflation, regurgitation, aspiration and decreased cardiac output; too little ventilation is also harmful.
Two rescuers use a bag-mask during adult CPR. What is the most effective division of tasks?
- a.One compresses and squeezes at once
- b.Both squeeze the bag together
- c.One holds the bag without a seal
- d.Two-hand seal; partner squeezes✓
Bag-mask ventilation is most effective with two trained rescuers, one sealing the mask with both hands and opening the airway while the other squeezes the bag.
An adult cannot be ventilated through the mouth because of facial trauma. What alternative is acceptable?
- a.No ventilation at all
- b.Mouth-to-nose ventilation✓
- c.Blowing into the ear
- d.Only compressions forever
Mouth-to-nose ventilation may be necessary when ventilating through the mouth is impossible because of trauma, positioning or difficulty obtaining a seal.
How quickly can oxygen saturation fall in a person with a pulse who stops breathing?
- a.Only after 10 minutes
- b.Only after 30 minutes
- c.Within about 90 seconds✓
- d.It never falls if the heart beats
The Guidelines note that after only 90 seconds of apnea, oxygen saturation can drop to dangerously low levels, which is why breaths are started quickly.
What ventilation rate is recommended for an intubated child during CPR?
- a.40 to 50 per minute
- b.10 per minute
- c.5 per minute
- d.20 to 30 per minute✓
For infants and children receiving CPR with an advanced airway, the Guidelines recommend 20 to 30 breaths per minute.
During 30:2 CPR, what can rescuers check at each ventilation pause that they cannot check during continuous compressions?
- a.Whether the AED is charged
- b.Whether the patient is warm
- c.Whether the pupils react
- d.Whether the chest rises✓
Ventilation adequacy cannot be evaluated during continuous compressions, so the Guidelines valued monitoring chest rise during 30:2 CPR; ventilations are often inadequate.
During infant CPR, a rescuer seals only the infant's mouth, and the chest does not rise. What should change?
- a.Cover the mouth and nose together✓
- b.Blow much harder into the mouth
- c.Stop breaths and compress only
- d.Give breaths through one nostril
MedlinePlus instructs rescuers to cover the infant's mouth and nose tightly with their mouth; each breath should make the chest rise without excessive force.
A patient has a laryngectomy stoma and needs breaths. What did one study find about mask choice?
- a.No mask can be used over a stoma
- b.The stoma should be covered to ventilate
- c.A round pediatric mask sealed best✓
- d.Standard adult masks sealed best
One study of patients with laryngectomies found a pediatric face mask created a better seal over the stoma than a standard ventilation mask.
Want these explained in order? ACLS & BLS Study Guide — 2026 Edition — PDF + EPUB, $24.99 · 14-day refund →
Why should rescuers take a normal breath rather than a deep one before giving mouth-to-mouth breaths?
- a.To deliver more oxygen
- b.To slow compressions down
- c.To keep the chest from rising
- d.To avoid dizziness✓
Taking a regular rather than a deep breath may prevent the rescuer from becoming lightheaded and prevents overinflating the patient's lungs.