**Question:** Which of the following is not true about cardiopulmonary resuscitation (CPR)?

A. Compression-only CPR is recommended for children under one year old.
B. Chest compressions should be performed at a rate of 100-120 compressions per minute for adults.
C. Open mouth, grip jaw, and chin lift manoeuvre is performed before bag-valve-mask ventilation in CPR.
D. The correct depth for chest compressions in adults is 5-6 cm.

**Correct Answer:** D. The correct depth for chest compressions in adults is 5-6 cm.

**Core Concept:** Cardiopulmonary resuscitation (CPR) is a life-saving technique performed when a person is found unresponsive with no breathing or inadequate breathing. The main goals of CPR are to maintain blood flow and oxygen supply to vital organs until the person receives advanced life support. This can be achieved through chest compressions, ventilation, and defibrillation.

**Why the Correct Answer is Right:** In adults, the depth of chest compressions is crucial for effective CPR. Compressions of 5-6 cm ensure adequate pressure generation, which promotes venous return and maintains coronary perfusion. This depth is appropriate for adult anatomy and helps to maintain adequate circulation during CPR.

**Why Each Wrong Option is Incorrect:**

A. Compression-only CPR for infants and children is based on their specific anatomy and physiology. For children, a compression depth of 2-2.5 cm is recommended, while for infants, it is 2 cm. In this scenario, the option is incorrect due to the incorrect depth for infants and children.

B. The correct rate for chest compressions in adults is 100-120 compressions per minute. A compression rate of 150-170 compressions per minute is appropriate for infants and children, not adults.

C. The jaw thrust and chin lift manoeuvre is used to open the airway in CPR, allowing for effective bag-valve-mask ventilation. This manoeuvre is performed before bag-valve-mask ventilation and not after.

D. The correct depth for chest compressions in adults is 5-6 cm, not the provided 2 cm. In adults, a compression depth of 5-6 cm ensures adequate pressure generation and coronary perfusion, which is essential for maintaining blood flow during CPR.

**Clinical Pearls:**

1. **Incorrect compressions depth for infants and children:** In infants and children, the appropriate compression depth is 2 cm, ensuring adequate pressure generation and coronary perfusion for these age groups.
2. **Incorrect compression rate for adults:** The correct compression rate for adults is 100-120 compressions per minute, not the provided 150-170 compressions per minute.
3. **Correct airway manoeuvre for bag-valve-mask ventilation:** In CPR, the jaw thrust and chin lift manoeuvre is performed to open the airway before bag-valve-mask ventilation, allowing for