Match the acid-base status of the following blood samples to the disorders in the given choices. (PaCO2 values are in mm Hg and bicarbonate values in mmol/l).
pH 7.55, PaCO2 25, HCO3- 22
A. Respiratory Acidosis, Partially Compensated
B. Respiratory Alkalosis, Uncompensated
C. Metabolic Alkalosis, Partially Compensated
D. Metabolic Acidosis, Uncompensated
Correct Answer: B. Respiratory Alkalosis, Uncompensated
Based on the given ABG values, pH is 7.55. For pH, the normal range is 7.35 to 7.45. Any blood pH above 7.45 (7.46, 7.47, 7.48, and so on…) is ALKALOSIS.
PaCO2 is 25. The normal range for PaCO2 is from 35 to 45. If PaCO2 is below 35, it is alkalosis. Based on the given ABG values, PaCO2 is below 35, so it is considered ALKALOSIS.
HCO3- is 22. The normal range for HCO3 is from 22 to 26. It is NORMAL.
For these ABG values, pH is ALKALOSIS and lines up with PaCO2 which is RESPIRATORY. Therefore, this group of ABG values is considered RESPIRATORY ALKALOSIS.
Lastly, it is UNCOMPENSATED because HCO3 is normal and PaCO2 is abnormal. It is uncompensated if PaCO2 or HCO3 is normal and the other is abnormal.