ACLS BLS and High-Quality CPR 3 — Questions and Answers
Question 1: During CPR on an adult, chest recoil between compressions is important primarily because it:
- Prevents rib fractures
- Allows the heart to refill with blood (Correct answer)
- Reduces rescuer fatigue
- Increases tidal volume during ventilation
Correct answer: Allows the heart to refill with blood
Full chest recoil allows venous blood to return to the heart (venous return), creating preload for the next compression.
Question 2: A 70 kg adult is in cardiac arrest. Bag-mask ventilation is being performed. What tidal volume is recommended per breath?
- 250–300 mL
- 500–600 mL (Correct answer)
- 800–1000 mL
- 1200–1500 mL
Correct answer: 500–600 mL
A tidal volume of 500–600 mL (enough to see chest rise) is recommended to avoid gastric insufflation and lung injury.
Question 3: Which of the following is the correct hand placement for adult chest compressions?
- Center of the chest on the upper half of the sternum
- Center of the chest on the lower half of the sternum (Correct answer)
- Left lateral chest over the heart's apex
- Xiphoid process at the very bottom of the sternum
Correct answer: Center of the chest on the lower half of the sternum
Hands are placed on the lower half of the sternum (center of the chest), which optimally compresses the heart between the sternum and spine.
Question 4: An advanced airway (endotracheal tube) is in place during CPR. How should ventilations be delivered?
- 30:2 ratio, pausing compressions for breaths
- 1 breath every 2–3 seconds, asynchronously with compressions
- 1 breath every 6 seconds, asynchronously with compressions (Correct answer)
- 2 breaths every 30 compressions, resuming compressions immediately
Correct answer: 1 breath every 6 seconds, asynchronously with compressions
Once an advanced airway is secured, ventilations are given asynchronously at a rate of 1 breath every 6 seconds (10 breaths/min) without interrupting compressions.
Question 5: What is a key indicator that CPR is resulting in ROSC (return of spontaneous circulation)?
- ETCO2 suddenly drops to below 10 mmHg
- ETCO2 abruptly rises to 35–40 mmHg (Correct answer)
- Pulse oximetry reads 100%
- Heart rate on monitor increases to 200 bpm
Correct answer: ETCO2 abruptly rises to 35–40 mmHg
A sudden rise in ETCO2 to near-normal levels (35–40 mmHg) indicates restored cardiac output and strongly suggests ROSC.
Question 6: Why should rescuers switch the compressor role approximately every 2 minutes during CPR?
- To prevent repetitive strain injuries to one rescuer
- Because fatigue causes compression depth to decrease within 2 minutes (Correct answer)
- To comply with AHA legal guidelines
- To synchronize with rhythm check intervals
Correct answer: Because fatigue causes compression depth to decrease within 2 minutes
Compressor fatigue causes subtle degradation of compression depth within 1–2 minutes, so switching during rhythm checks maintains quality.
Question 7: During a resuscitation attempt, the team leader notices the compressor is 'bouncing' on the patient's chest. What is the correct response?
- Encourage faster rate to compensate
- Instruct the compressor to allow full chest recoil without leaning (Correct answer)
- Accept it as a normal variation in technique
- Replace the compressor immediately and discontinue attempts for that rescuer
Correct answer: Instruct the compressor to allow full chest recoil without leaning
Leaning on the chest between compressions prevents full recoil, reducing cardiac filling; the compressor should be corrected immediately.
ACLS BLS and High-Quality CPR 3
During CPR on an adult, chest recoil between compressions is important primarily because it: