AEMCA Practice Exam

What is a common physiological response to hypoxemia?

1. Respiratory acidosis

2. Respiratory alkalosis

3. Metabolic acidosis

4. Metabolic alkalosis

The correct answer is: Respiratory acidosis

A common physiological response to hypoxemia, which is a deficiency in the amount of oxygen reaching the tissues, includes the development of respiratory acidosis. When the body experiences hypoxemia, it often triggers an increase in the rate and depth of breathing in an attempt to improve oxygen intake. However, if the hypoxemia is severe or prolonged, the body may struggle to expel carbon dioxide efficiently due to inadequate gas exchange. This leads to a buildup of carbon dioxide in the blood, which reacts with water to form carbonic acid, ultimately lowering the pH of the blood and resulting in respiratory acidosis. In contrast, the other options listed pertain to conditions of acid-base balance that are not the primary physiological response to hypoxemia. Respiratory alkalosis occurs when there is excessive loss of carbon dioxide due to hyperventilation, while metabolic acidosis and alkalosis relate to disturbances in acid-base balance associated with metabolic processes, rather than being direct responses to low oxygen levels. Therefore, respiratory acidosis is the most common physiological response observed in cases of hypoxemia.