The nurse is caring for a client with respiratory insufficiency. The arterial blood gas (ABG) results indicate a pH of 7.50 and a PaCO2 of 30 mm Hg, and the nurse concludes that the client is experiencing respiratory alkalosis. Which additional laboratory value would the nurse expect to note in this client?

Choice A reason: This is incorrect because diffusion is the movement of solutes (dissolved substances) from an area of higher concentration to an area of lower concentration, until equilibrium is reached.

Choice B reason: This is incorrect because hydrostatic pressure is the force exerted by a fluid against a wall or a membrane. Hydrostatic pressure can drive the movement of fluid and solutes across a membrane, but it is not the movement itself.

Choice C reason: This is correct because osmosis is the movement of a pure solvent (liquid) across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration, until equilibrium is reached.

Choice D reason: This is incorrect because ATP is not a movement, but a molecule. ATP stands for adenosine triphosphate, which is the main source of energy for cellular processes. ATP can provide energy for some types of transport across membranes, such as active transport.

Choice A reason: 60 mL of urine in a 2-hour period is not very concerning for a nurse, as it is within the normal range of urine output. The average urine output for an adult is about 1 to 2 L per day, or 40 to 80 mL per hour¹.

Choice B reason: 720 mL of urine in a 24-hour period is slightly below the normal range, but not alarming. It may indicate mild dehydration or reduced fluid intake, but it is not a sign of fluid volume excess or kidney failure¹.

Choice C reason: 600 mL of urine in a 10-hour period is also within the normal range of urine output, and does not indicate any problem with fluid balance or renal function¹.

Choice D reason: 100 mL of urine in a 5-hour period is the most concerning for a nurse, as it indicates oliguria, or abnormally low urine output. Oliguria is defined as urine output less than 400 mL per day, or less than 20 mL per hour². It may be caused by acute or chronic kidney injury, urinary obstruction, shock, dehydration, or fluid volume excess². Oliguria can lead to fluid overload, electrolyte imbalance, acidosis, and uremia, and requires immediate medical attention².