Choice A reason: This is a low value for serum calcium, which indicates hypocalcemia. Hypocalcemia can cause muscle spasms, tetany, seizures, and cardiac arrhythmias.

Choice B reason: This is also a low value for serum calcium, which indicates hypocalcemia. Hypocalcemia can cause muscle spasms, tetany, seizures, and cardiac arrhythmias.

Choice C reason: This is the normal range of serum calcium in adults. Calcium is essential for bone health, muscle contraction, nerve transmission, and blood clotting.

Choice D reason: This is a high value for serum calcium, which indicates hypercalcemia. Hypercalcemia can cause nausea, vomiting, constipation, confusion, lethargy, and kidney stones.

Choice A reason: This is incorrect because metabolic alkalosis is characterized by a high pH and a high HCO3-. The patient's pH and HCO3- are both low, indicating acidosis, not alkalosis.

Choice B reason: This is incorrect because respiratory alkalosis is characterized by a high pH and a low PaCO2. The patient's pH is low and PaCO2 is normal, indicating a metabolic problem, not a respiratory one.

Choice C reason: This is incorrect because respiratory acidosis is characterized by a low pH and a high PaCO2. The patient's pH is low, but PaCO2 is normal, indicating a metabolic problem, not a respiratory one.

Choice D reason: This is correct because metabolic acidosis is characterized by a low pH and a low HCO3-. The patient's pH and HCO3- are both low, indicating a metabolic disorder. The condition is uncompensated because the PaCO2 is normal, meaning the respiratory system is not compensating for the metabolic acidosis.

Choice A reason: This is incorrect because filtration is a passive transport mechanism that does not require cellular energy. Filtration is the movement of fluid and solutes across a membrane due to hydrostatic pressure.

Choice B reason: This is correct because active transport is a transport mechanism that requires cellular energy in the form of ATP. Active transport is the movement of molecules across a membrane against their concentration gradient, using carrier proteins.

Choice C reason: This is incorrect because diffusion is a passive transport mechanism that does not require cellular energy. Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration, until equilibrium is reached.

Choice D reason: This is incorrect because osmosis is a passive transport mechanism that does not require cellular energy. Osmosis is the movement of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Choice A reason: This is incorrect because amino acids are electrolytes. Electrolytes are substances that dissociate into ions when dissolved in water and conduct electricity. Amino acids have both positive and negative charges and can form ions in solution.

Choice B reason: This is incorrect because magnesium is an electrolyte. Magnesium is a metal that forms positive ions (cations) when dissolved in water. Magnesium is important for muscle and nerve function, as well as bone health.

Choice C reason: This is incorrect because phosphates are electrolytes. Phosphates are compounds that contain the phosphate ion (PO4 3-), which is a negative ion (anion) in solution. Phosphates are involved in energy metabolism, acid-base balance, and bone formation.

Choice D reason: This is correct because glucose is a nonelectrolyte. Nonelectrolytes are substances that do not dissociate into ions when dissolved in water and do not conduct electricity. Glucose is a simple sugar that dissolves as a whole molecule in water. Glucose is the main source of energy for the body.

Choice A: Elderly patients are at a higher risk for dehydration due to physiological changes that come with aging, such as decreased kidney function and physical changes to the body's water balance systems. Additionally, fever increases metabolic rate and fluid loss, and nausea and vomiting prevent adequate fluid intake, further increasing the risk of dehydration.

Choice B: While intentionally limiting fluid intake can lead to dehydration, the body's thirst mechanism in a healthy teenager is typically strong enough to prevent severe dehydration.

Choice C: Diarrhea can certainly lead to dehydration, but a young, otherwise healthy patient typically has a stronger ability to recover from fluid loss than an elderly patient.

Choice D: Infants are at a higher risk for dehydration than older children and adults due to their smaller body weight and higher turnover of water and electrolytes, but in this case, the elderly patient's multiple risk factors put them at a higher risk overall.

Choice A reason: This is correct because metabolic alkalosis is characterized by a high pH and a high HCO3-. The client's pH and HCO3- are both high, indicating a metabolic disorder. The condition is uncompensated because the PaCO2 is normal, meaning the respiratory system is not compensating for the metabolic alkalosis.

Choice B reason: This is incorrect because metabolic acidosis is characterized by a low pH and a low HCO3-. The client's pH and HCO3- are both high, indicating alkalosis, not acidosis.

Choice C reason: This is incorrect because respiratory alkalosis is characterized by a high pH and a low PaCO2. The client's pH is high, but PaCO2 is normal, indicating a metabolic problem, not a respiratory one.

Choice D reason: This is incorrect because respiratory acidosis is characterized by a low pH and a high PaCO2. The client's pH is high, and PaCO2 is normal, indicating a metabolic problem, not a respiratory one.

Choice A reason: This is incorrect because 120 to 140 mEq/L is a low range for serum sodium, which indicates hyponatremia. Hyponatremia can cause confusion, lethargy, seizures, and coma.

Choice B reason: This is correct because 135 to 145 mEq/L is the normal range of serum sodium in adults. Sodium is essential for fluid balance, nerve transmission, and muscle contraction.

Choice C reason: This is incorrect because 150 to 160 mEq/L is a high range for serum sodium, which indicates hypernatremia. Hypernatremia can cause thirst, dry mouth, agitation, and convulsions.

Choice D reason: This is incorrect because 165 to 175 mEq/L is a very high range for serum sodium, which indicates severe hypernatremia. Severe hypernatremia can cause irreversible brain damage and death.

Choice A reason: This is incorrect because polyuria is a sign of hyponatremia, not hypernatremia. Polyuria is the excessive production of urine, which can cause fluid loss and sodium dilution.

Choice B reason: This is correct because dry mucous membranes are a sign of hypernatremia. Dry mucous membranes are caused by dehydration, which can occur in hypernatremia due to fluid shifting from the intracellular to the extracellular space.

Choice C reason: This is incorrect because diarrhea is a sign of hyponatremia, not hypernatremia. Diarrhea is the frequent and watery passage of stool, which can cause fluid and electrolyte loss.

Choice D reason: This is incorrect because intense thirst is a sign of both hyponatremia and hypernatremia. Intense thirst is a result of the body's attempt to restore fluid balance and osmolarity.

Choice E reason: This is incorrect because vomiting is a sign of both hyponatremia and hypernatremia. Vomiting is a reflex action that expels the contents of the stomach, which can cause fluid and electrolyte loss or imbalance.

Choice A reason: This is incorrect because bradypnea is a term for slow breathing, usually less than 12 breaths per minute. The client is breathing rapidly, not slowly.

Choice B reason: This is correct because Kussmaul's respirations are a type of breathing pattern that is deep, regular, and rapid, usually more than 20 breaths per minute. Kussmaul's respirations are a sign of metabolic acidosis, which occurs in diabetic ketoacidosis due to the accumulation of ketones in the blood. The client is trying to exhale the excess carbon dioxide and lower the acidity of the blood.

Choice C reason: This is incorrect because Cheyne-Stokes respirations are a type of breathing pattern that is irregular, with periods of apnea (no breathing) alternating with periods of rapid breathing. Cheyne-Stokes respirations are a sign of cerebral dysfunction, such as stroke, brain injury, or coma.

Choice D reason: This is incorrect because Biot's respirations are a type of breathing pattern that is irregular, with periods of apnea (no breathing) interspersed with periods of normal breathing. Biot's respirations are a sign of brainstem damage, such as meningitis, encephalitis, or head trauma.

Choice A reason: This is incorrect because sodium level of 145 mEq/L is within the normal range of 135 to 145 mEq/L. Sodium is not directly affected by respiratory alkalosis, but it may be altered by fluid balance or other conditions.

Choice B reason: This is incorrect because magnesium level of 1.3 mEq/L is within the normal range of 1.3 to 2.1 mEq/L. Magnesium is not directly affected by respiratory alkalosis, but it may be altered by renal function or other conditions.

Choice C reason: This is incorrect because phosphorus level of 3.0 mg/dL is within the normal range of 2.5 to 4.5 mg/dL. Phosphorus is not directly affected by respiratory alkalosis, but it may be altered by calcium balance or other conditions.

Choice D reason: This is correct because potassium level of 3.0 mEq/L is below the normal range of 3.5 to 5.0 mEq/L. Potassium is inversely related to hydrogen ions, which are decreased in respiratory alkalosis. As hydrogen ions move out of the cells to buffer the blood, potassium ions move into the cells to maintain electrical neutrality. This causes hypokalemia, or low potassium level.