A patient who is hospitalized due to vomiting and a decreased level of consciousness displays slow and deep (Kussmaul breathing), and he is lethargic and irritable in response to stimulation. The doctor diagnosed him of having dehydration. Measurement of arterial blood gas shows pH 7.0, PaO2 90 mm Hg, PaCO2 22 mm Hg, and HCO3 14 mmol/L; other results are Na+ 120 mmol/L, K+ 2.5 mmol/L, and Cl- 95 mmol/L. As a knowledgeable nurse, you know that the normal value for PaCO2 is:
A. 22 mm Hg
B. 36 mm Hg
C. 48 mm Hg
D. 50 mm Hg
Correct Answer: B. 36 mm Hg
The normal range for PaCO2 is from 35 to 45 mm Hg.