Advanced Patient Assessment Practice Exam

What problem is indicated by cyanosis of the oral mucosa?

1. Reduced arterial oxygenation

2. Low cardiac output

3. Hyperventilation

4. Hypoventilation

The correct answer is: Reduced arterial oxygenation

Cyanosis of the oral mucosa typically indicates a problem with reduced arterial oxygenation. When hemoglobin is inadequately saturated with oxygen, it can lead to a bluish discoloration of the mucous membranes, such as those found in the mouth. This phenomenon occurs because decreased oxygen levels in the blood result in a higher concentration of deoxygenated hemoglobin, which appears darker and contributes to the bluish tint. In this context, while low cardiac output could contribute to decreased oxygen delivery to tissues, it is the oxygen saturation of the blood that directly causes cyanosis. Hyperventilation, which is rapid or deep breathing, typically leads to decreased carbon dioxide levels in the blood and does not cause cyanosis. Conversely, hypoventilation, or insufficient breathing, can indeed lead to carbon dioxide retention and subsequent respiratory acidosis, but it often does not manifest as cyanosis of the oral mucosa in the same immediate way that reduced arterial oxygenation does. Understanding the relationship between oxygenation levels and the appearance of cyanosis helps in assessing potential respiratory or cardiovascular issues requiring further evaluation and intervention.