After intubation of a cardiac arrest victim, you observe a slow ...

[crazycityslicker]

After intubation of a cardiac arrest victim, you observe a slow but steady rise in the expired CO2 levels as measured by a bedside capnometer. Which of the following best explains this observa-tion?
 
  a. Return of spontaneous circulation
  b. Abnormally high
  c. Placement of the endotracheal tube in the esophagus
  d. Failure of the cuff to properly seal the airway

Question 2

When using capnometry or colorimetry to differentiate esophageal from tracheal placement of an endotracheal tube, which of the following conditions can result in a false-negative finding (i.e., no CO2 present even when the tube is in the trachea)?
 
  a. Cardiac arrest
  b. Gastric CO2 diffusion
  c. Right main stem intubation
  d. Delivery of a high FiO2

[Viet Thy]

Answer to Question 1

ANS: A
Generally, expired CO2 levels increase with the return of spontaneous circulation.

Answer to Question 2

ANS: A
In cardiac arrest victims, however, expired CO2 levels may be near zero because of poor pulmo-nary blood flow, yielding a false-negative result.