Based on the AHA 2020 BLS Guidelines, here are the answers to all 8 visible questions, including a review of the marked answers:
BLS Assessment - Full Answer Key (AHA 2020)
| Q# | Question | Correct Answer | Marked Answer | Status |
|---|
| 1 | Recommended compression rate for high-quality CPR in adults | A) 100-120 compressions/min | A ✓ | ✅ Correct |
| 2 | Correct hand placement for adult chest compressions | D) Centre of the chest, lower half of the sternum | D ✓ | ✅ Correct |
| 3 | What ensures adequate chest recoil during CPR? | D) Allowing the chest to fully rise between compressions without leaning on it | Not clearly marked | - |
| 4 | Compression-to-ventilation ratio in 2-rescuer adult CPR | A) 30:2 | A ✓ | ✅ Correct |
| 5 | Preferred 2-rescuer technique for infant compressions | B) Two thumbs-encircling hands technique | Not marked | - |
| 6 | Correct compression depth for a child (1 year to puberty) | C) At least 2 inches (5 cm) | Not marked | - |
| 7 | Duration of each rescue breath in adults | D) 1 second | Not marked | - |
| 8 | Sign of effective rescue breathing | B) Visible chest rise | Not marked | - |
Detailed Explanations (AHA 2020)
Q1 - Compression Rate: 100-120/min is the target rate. Too slow reduces cardiac output; too fast reduces filling time and compression depth.
Q2 - Hand Placement: Heel of both hands on the lower half of the sternum, centre of chest. NOT over the xiphoid process (risk of liver laceration).
Q3 - Chest Recoil: Full recoil between compressions allows the heart to refill with blood. Leaning on the chest prevents complete recoil and reduces venous return.
Q4 - 30:2 Ratio: In both single and 2-rescuer adult CPR, the ratio is 30 compressions : 2 breaths. (For 2-rescuer infant/child CPR, it changes to 15:2.)
Q5 - Infant 2-rescuer: The two thumbs-encircling technique is preferred for 2 rescuers because it generates better coronary perfusion pressure than the 2-finger technique (which is for single rescuers).
Q6 - Child Compression Depth: At least 2 inches (5 cm), but not more than 2.4 inches (6 cm). Adult depth is also at least 2 inches.
Q7 - Rescue Breath Duration: Each breath over 1 second, enough to see visible chest rise. Longer breaths increase gastric inflation risk.
Q8 - Effective Rescue Breathing: Visible chest rise is the primary indicator. Cyanosis resolution is secondary; gastric sounds and abdominal distension indicate incorrect technique (air going into stomach).
Note on Q3: Option C says "Allowing the chest to fully rise between compressions" but Option D adds "without leaning on it" - D is the more complete and correct answer per AHA guidelines, which specifically warn against leaning.
The passing score is 84% (21/25 correct). The 3 marked answers visible are all correct!