What arterial blood gas values are most likely to appear for a patient who is hyperventilating?

In cases of hyperventilation, the primary physiological change observed in arterial blood gas (ABG) values is a decrease in carbon dioxide (CO2) levels due to excessive exhalation. This increased rate of breathing leads to respiratory alkalosis, which is characterized by a higher pH level.

The values for pH, CO2, and bicarbonate (HCO3) in the correct answer reflect this condition well: with a pH of 7.55, the level is elevated, indicating alkalosis. Simultaneously, the CO2 level is at 22 mmHg, which is significantly lower than normal, confirming hyperventilation and the resulting hypocapnia (low CO2 levels). The bicarbonate level at 24 mEq/L remains within the normal range, supporting the idea that there is no metabolic compensation occurring, as the primary issue is respiratory in nature.

These values are consistent with the physiological response seen in hyperventilating patients, making them the most accurate representation of the condition.