Questions: Patient Assessment - B: Question 2 of 15 A patient is found in full cardiopulmonary arrest. CPR is started and the patient is orally intubated with an ETCO2 monitor attached. Which of the following ETCO2 patterns would the respiratory therapist expect to observe on the monitor? A. Initially high, then falling B. Initially low, then rising C. Initially high, stays high D. Initially low, stays low

The answer is B: Initially low, then rising.

Explanation for each option:

A. Initially high, then falling - This pattern is not typical in a patient undergoing CPR. High initial $\mathrm{ETCO}_{2}$ levels would suggest effective perfusion and ventilation, which is unlikely in a patient in full cardiopulmonary arrest.

B. Initially low, then rising - This is the expected pattern. In cardiopulmonary arrest, perfusion is poor, leading to low $\mathrm{ETCO}_{2}$ levels initially. As CPR is performed and circulation improves, $\mathrm{ETCO}_{2}$ levels should rise, indicating better perfusion and effective chest compressions.

C. Initially high, stays high - This pattern is not expected in a patient in full cardiopulmonary arrest. High $\mathrm{ETCO}_{2}$ levels throughout would suggest continuous effective perfusion, which is not the case in arrest situations.

D. Initially low, stays low - This pattern would indicate ineffective CPR or continued poor perfusion, which is not the goal of resuscitation efforts. Effective CPR should result in rising $\mathrm{ETCO}_{2}$ levels.

Summary: In a patient in full cardiopulmonary arrest, the respiratory therapist would expect to see $\mathrm{ETCO}_{2}$ levels that are initially low and then rise as CPR improves circulation. Therefore, the correct answer is B: Initially low, then rising.