A nurse is reviewing the laboratory values of a school-age child who has nephrotic syndrome. Which of the following laboratory values should the nurse expect?

Choice A reason: Hemoglobin (Hgb) of 12 g/dL is within the normal range for school-age children and is not specifically indicative of nephrotic syndrome.

Choice B reason: A serum protein level of 4.2 g/dL is lower than the normal range, which is typically between 6 and 8 g/dL. This finding is consistent with nephrotic syndrome, as the condition is characterized by proteinuria and hypoalbuminemia, leading to low serum protein levels.

Choice C reason: A BUN (Blood Urea Nitrogen) level of 15 mg/dL is within the normal range for children and does not specifically indicate nephrotic syndrome. Nephrotic syndrome is characterized by protein loss, not necessarily changes in BUN levels.

Choice D reason: A serum sodium level of 144 mEq/L is within the normal range for children. While electrolyte imbalances can occur in nephrotic syndrome, this value does not specifically indicate the condition.

Choice A reason: The concrete operational phase typically begins around age 7 and is characterized by the development of logical thought about concrete events. This phase is not typical for preschoolers, who are usually between the ages of 3 and 5.

Choice B reason: The formal operational phase usually starts at age 11 or older. It involves abstract thinking and the ability to systematically plan for the future, which is beyond the cognitive abilities of a preschooler.

Choice C reason: The preoperational phase occurs from ages 2 to 7. During this stage, children begin to engage in symbolic play and learn to manipulate symbols, but they do not yet understand concrete logic.

Choice D reason: The sensorimotor phase is from birth to about age 2. During this stage, infants learn about the world through their senses and actions, such as looking and touching. Preschoolers have typically moved beyond this phase.