Answer to Question 1
B
Serum sodium may be low as a result of the movement of water from the intracellular space into the extracellular (vascular) space. The serum potassium level is often normal; a low serum potassium level in diabetic ketoacidosis suggests that a significant potassium deficiency may be present.
Answer to Question 2
A
Pulmonary artery occlusion pressure (PAOP) and pulmonary artery wedge pressure (PAWP) normally reflect the pressure in the left ventricle at the end of diastole. Left ventricular end-diastolic pressure is preload, and so an increase in preload will first increase the PAOP and PCWP measurements. Although central venous pressure increases in severe cases of increased preload, it can increase for other reasons. The other changes are not associated with increased preload.