Lena Mason, who has diabetes, is admitted in a stuporous condition. Her blood gases show a pH of 7.33, PaCO2 of 40 mm Hg, and HCO3- of 20 mEq/L. What type of acid-base imbalance does this patient have?

Choice A reason: This is correct because prolonged bed rest can cause hypocalcemia, or low serum calcium level. Calcium is stored in the bones and is released into the blood when the bones are stressed by weight-bearing activities. When a person is on bed rest, the bones are not stimulated and the calcium remains in the bones, leading to a decrease in serum calcium level.

Choice B reason: This is incorrect because too much butter consumption does not affect the serum calcium level directly. Butter is a source of fat and calories, which can affect the cholesterol and triglyceride levels, but not the calcium level. However, too much butter consumption can cause obesity, which can increase the risk of osteoporosis and fractures.

Choice C reason: This is incorrect because hyperparathyroidism can cause hypercalcemia, or high serum calcium level. Hyperparathyroidism is a condition where the parathyroid glands produce too much parathyroid hormone (PTH), which regulates the calcium and phosphorus balance in the body. PTH stimulates the release of calcium from the bones into the blood, leading to an increase in serum calcium level.

Choice D reason: This is incorrect because excessive ingestion of vitamin D can also cause hypercalcemia, or high serum calcium level. Vitamin D is a fat-soluble vitamin that helps the body absorb calcium from the food and supplements. When a person takes too much vitamin D, the calcium absorption is increased and the serum calcium level rises.

Choice A reason: This is incorrect because 95-110 mg/dL is the normal range of serum phosphorus level in adults, not chloride. Phosphorus is an electrolyte that is involved in energy metabolism, acid-base balance, and bone formation.

Choice B reason: This is incorrect because 10-120 mEq/L is not a realistic range for any electrolyte level in the blood. The units of mEq/L indicate the concentration of ions, not the mass of the substance. The normal range of serum chloride level in adults is expressed in mEq/L, not mg/dL.

Choice C reason: This is correct because 96-106 mEq/L is the normal range of serum chloride level in adults. Chloride is an electrolyte that is important for fluid balance, acid-base balance, and nerve transmission.

Choice D reason: This is incorrect because 1.8-2.6 mEq/L is the normal range of serum magnesium level in adults, not chloride. Magnesium is an electrolyte that is important for muscle and nerve function, as well as enzyme activity.