Correct Answer: A

Rationale: Diabetes insipidus is characterized by a deficiency in antidiuretic hormone (ADH), leading to excessive urine output and thirst.

Correct Answer: B

Rationale: Osmosis is the movement of fluid from a region of low solute concentration to a region of high solute concentration across a semipermeable membrane. The number of dissolved particles contained in a unit of fluid determines the osmolality of a solution, which influences the movement of fluid between the fluid compartments. Giving a patient who has a low blood pressure a hypertonic solution will increase the number of dissolved particles in the blood, creating pressure for fluids in the tissues to shift into the capillaries and increase the blood volume. Option A is incorrect; hydrostatic pressure refers to changes in water or volume related to water pressure. Option C is incorrect; diffusion is the movement of solutes from an area of greater concentration to lesser concentration. The solutes in an intact vascular system are unable to move, so diffusion should not normally take place. Option D is incorrect; active transport is the movement of molecules against the concentration gradient and requires ATP as an energy source. This process typically takes place at the cellular level and is not involved in vascular volume changes.

Correct Answer: A

Rationale: A pH of less than 7.40, a PaCO2 greater than 40, and an HCO3 of 24 are normal; therefore, it is a respiratory acidosis. Compensation by the kidneys has not begun, which indicates this was probably an acute event.

Correct Answer: C

Rationale: Infiltration is the administration of nonvesicant solution or medication into the surrounding tissue. This can occur when the IV cannula dislodges or perforates the wall of the vein. Infiltration is characterized by edema around the insertion site, leakage of IV fluid from the insertion site, discomfort and coolness in the area of infiltration, and a significant decrease in the flow rate.

Correct Answer: C

Rationale: Furosemide is a potassium-wasting diuretic. A low potassium level may cause weakness and palpitations. Telling the patient to rest more often won't help the patient if she's hypokalemic. Digoxin isn't causing the patient's symptoms, so she doesn't need to stop taking it. The patient should probably avoid caffeine, but this wouldn't resolve potassium depletion.