Which type of acid-base imbalance occurs as a result of hyperventilation?

Hyperventilation leads to an increased rate and depth of breathing, which causes an excessive expulsion of carbon dioxide (CO2) from the bloodstream. This significant loss of CO2 results in a decrease in the partial pressure of carbon dioxide (pCO2) in the arterial blood, which directly affects the acid-base balance.

In the context of acid-base physiology, carbon dioxide is an important component in the bicarbonate buffering system. When CO2 levels drop due to hyperventilation, the equilibrium shifts, leading to a decrease in hydrogen ion concentration (H+) in the blood, making it less acidic. This condition is classified as respiratory alkalosis.

Respiratory alkalosis is characterized by a pH greater than 7.45 and a reduced pCO2, which corresponds with the physiological changes that occur during hyperventilation. Therefore, this explains why the correct answer is respiratory alkalosis, reflecting the body's response to increased respiration and the resulting drop in carbon dioxide levels.