In a patient who is hemodynamically stable,which procedure can be used to estimate the PaCO₂ levels?
A) PaO₂/FiO₂ ratio
B) A-a gradient
C) Residual volume (RV)
D) End-tidal CO₂

Question

Quizplus · Accepted Answer

Capnography is the measurement of exhaled carbon dioxide (CO₂)gas; it is also known as end-tidal CO₂ monitoring.Normally,alveolar and arterial CO₂ concentrations are equal in the presence of normal ventilation-perfusion (V/Q)relationships.In a patient who is hemodynamically stable,the end-tidal CO₂ (PetCO₂)can be used to estimate the PaCO₂.Normally,the PaO₂/FiO₂ ratio is greater than 286; the lower the value,the worse the lung function.The A-a gradient is normally less than 20 mm Hg on room air for patients younger than 61 years.This estimate of intrapulmonary shunting is the least reliable clinically,but it is used often in clinical decision making.Residual volume is the amount of air left in the lung after maximal exhalation.A normal value is 1200 to 1300 mL.

In a Patient Who Is Hemodynamically Stable,which Procedure Can Be