Advanced Patient Assessment Practice Exam

A patient has the following ABG results: pH: 7.25; PaCO2: 32 mm Hg; HCO3: 16 mEq/L. Based on these findings, the patient has which of the following?

1. Compensated metabolic acidosis

2. Compensated respiratory acidosis

3. Uncompensated respiratory acidosis

4. Uncompensated metabolic acidosis

The correct answer is: Uncompensated metabolic acidosis

The ABG results indicate a pH of 7.25, which is below the normal range of 7.35-7.45, indicating acidosis. The HCO3 (bicarbonate) level is at 16 mEq/L, which is low, further supporting the diagnosis of acidosis. The low bicarbonate level confirms that the primary disturbance is metabolic in nature since it is suggestive of metabolic acidosis due to the body’s inability to maintain normal bicarbonate levels. The normal range for bicarbonate is typically 22-26 mEq/L. A bicarbonate level below this range indicates acidemia due to an excess of hydrogen ions or a loss of bicarbonate. Given that the pH is low and the bicarbonate level is significantly decreased, these findings are consistent with uncompensated metabolic acidosis. The PaCO2 value of 32 mm Hg is slightly low, which may suggest a respiratory compensation attempt. However, the level of compensation is not adequate to bring the pH back within the normal range, indicating that compensation has not yet occurred adequately or that the metabolic acidosis is acute rather than chronic. Therefore, the correct designation for these ABG results is uncompensated metabolic acidosis, as