**Question:** During CPCR (Continuous Positive Airway Pressure Continuous Remineralization) in ACLS (Advanced Cardiovascular Life Support), the waveform of capnograph shows the following change. This indicates:-

A. Increased amplitude and duration of expiratory spike
B. Decreased amplitude and duration of expiratory spike
C. No change in capnograph waveform
D. Absence of capnograph waveform

**Correct Answer:** B. Decreased amplitude and duration of expiratory spike

**Core Concept:** Capnography is a non-invasive method of monitoring the airway pressure and assessing the adequacy of ventilation during CPAP (Continuous Positive Airway Pressure) therapy. In ACLS, capnography is essential for confirming the correct placement of the endotracheal tube and assessing the adequacy of ventilation.

**Why the Correct Answer is Right:** During CPCR, the capnograph waveform is expected to show a decrease in amplitude and duration of the expiratory spike. This is because CPCR is a form of positive pressure ventilation that involves adding continuous positive airway pressure (CPAP) to maintain the patency of the airway and ensure adequate ventilation.

**Why Each Wrong Option is Incorrect:**

A. Increased amplitude and duration of expiratory spike: This would indicate inadequate ventilation, not sufficient CPAP, as the increased pressure would be counterproductive and could cause end-expiratory hypercapnia.

C. No change in capnograph waveform: This indicates that the ventilation is inadequate, and CPAP is not working effectively to maintain airway patency and ensure adequate ventilation.

D. Absence of capnograph waveform: Absence of the capnograph waveform indicates improper placement of the endotracheal tube, inadequate ventilation, or a faulty device.

**Clinical Pearl:** In ACLS, capnography is a valuable tool for confirming the placement of the endotracheal tube and assessing the adequacy of ventilation during CPCR. A decrease in amplitude and duration of the expiratory spike is expected due to the application of CPAP. Regular monitoring and adjustment of CPAP pressure ensures optimal ventilation and prevents hypercapnia and hypoxia.