1. The correct answer is b. The greater the proportion of body water, the greater the risk. Choices a, c, and d are at no particular risk. Athletes may be more so if doing strenuous exercise in high temperature environments and if not replacing their fluids periodically.

2. The correct answer is d. When large amounts of fluid become sequestered in a body compartment and therefore are unavailable for body processes, it is referred to as third spacing. Choices a, b, and c are not examples of third spacing, which ordinarily refers to large fluid shifts.

3. The correct answer is d. Fever increases metabolism and therefore increases fluid needs. Choices a, b, and c do not increase fluid needs.

4. The correct answer is a. An important function of albumin is to maintain osmotic pressure. Choices b, c, and d do not cause edema.

5. The correct answer is b. Ileus results from the decreased peristalsis that is a consequence of reduced neuromuscular function and is one of the earlier clinical signs of hypokalemia. Tetany results from hypocalcemia, thirst is associated with hypernatremia, and paresthesias sometimes occur with respiratory alkalosis.

6. The correct answer is d. It is important to report even small variations in potassium outside the normal values for your institution due to the importance of this electrolyte in cardiac function. The other choices are incorrect because although normal values vary from lab to lab, the commonly accepted normal range is from 3.5 to 5.

7. The correct answer is b. Potassium is the major intracellular ion. Sodium is the major extracellular ion. Although important, neither choice c nor d is considered to be a major ion.

8. The correct answer is a. Confusion often occurs early and is especially important to watch for in the elderly. The other choices are incorrect because diarrhea occurs with hyperkalemia, muscle spasms occur with hypocalcemia, and insomnia is not relevant.

9. The correct answer is b. In acidosis, as hydrogen enters the cell, it causes potassium to leave, resulting in hyperkalemia. The other choices are incorrect because hypokalemia results in muscle weakness, atony, and electrocardiographic changes; hypocalcemia causes tetany, and hypercalcemia causes muscle weakness and renal stones.