Advanced Medical Life Support (AMLS)

Which of the following is a common cause of respiratory alkalosis?

1. Fever and anxiety

2. Renal failure and dehydration

3. Airway obstruction and chest wall pain

4. Prolonged vomiting

The correct answer is: Fever and anxiety

Respiratory alkalosis occurs when there is a decrease in carbon dioxide (CO2) levels in the blood, resulting from hyperventilation. Hyperventilation can be triggered by conditions that increase the rate of respiration, such as fever and anxiety. In the case of fever, the body's metabolic rate increases, often leading to faster breathing as the body attempts to compensate for increased oxygen demand and to eliminate excess carbon dioxide. Similarly, anxiety can induce rapid and shallow breathing patterns, which also contribute to decreased carbon dioxide levels in the blood. This physiological response is central to understanding respiratory alkalosis, making fever and anxiety the appropriate choice when identifying common causes related to this condition. Other options involve mechanisms or conditions that would not primarily lead to respiratory alkalosis. For instance, renal failure and dehydration are more commonly associated with metabolic acidosis rather than respiratory alkalosis. Airway obstruction and chest wall pain typically lead to hypoventilation and increased carbon dioxide levels, contributing to respiratory acidosis. Prolonged vomiting can lead to metabolic alkalosis due to the loss of stomach acid, rather than affecting respiratory gas exchange directly.