the chief mechanism for maintaining fluid balance is to

ATI RN

ATI Fluid and Electrolytes

1. The chief mechanism for maintaining fluid balance is to:

A. adjust fluid intake so it equals fluid output.
B. adjust fluid intake so it is slightly above fluid output.
C. adjust fluid output so it equals fluid input.
D. adjust fluid intake so it is slightly below fluid output.

Correct answer: C

Rationale: The correct answer is C: 'adjust fluid output so it equals fluid input.' Maintaining fluid balance involves ensuring that the amount of fluid lost through processes like urination, sweating, and respiration equals the amount of fluid taken in. This ensures that the body stays properly hydrated. Choices A, B, and D are incorrect because they do not focus on the balance between fluid input and output, which is crucial for maintaining proper fluid balance. By adjusting fluid output to equal fluid input, the body can regulate hydration levels effectively, preventing dehydration or overhydration.

2. A nurse in the medical-surgical unit is giving a patient with low blood pressure a hypertonic solution, which will increase the number of dissolved particles in his blood, creating pressure for fluids in the tissues to shift into the capillaries and increase the blood volume. Which of the following terms is associated with this process?

A. Hydrostatic pressure
B. Osmosis and osmolality
C. Diffusion
D. Active transport

Correct answer: B

Rationale: Osmosis is the movement of fluid from a region of low solute concentration to a region of high solute concentration across a semipermeable membrane. The number of dissolved particles contained in a unit of fluid determines the osmolality of a solution, which influences the movement of fluid between the fluid compartments. Giving a patient who has low blood pressure a hypertonic solution will increase the number of dissolved particles in the blood, creating pressure for fluids in the tissues to shift into the capillaries and increase the blood volume. Option A is incorrect; hydrostatic pressure refers to changes in water or volume related to water pressure. Option C is incorrect; diffusion is the movement of solutes from an area of greater concentration to lesser concentration. The solutes in an intact vascular system are unable to move, so diffusion should not normally take place. Option D is incorrect; active transport is the movement of molecules against the concentration gradient and requires ATP as an energy source. This process typically takes place at the cellular level and is not involved in vascular volume changes.

3. A nurse is planning care for a client who is hyperventilating. The clients arterial blood gas values are pH 7.30, PaO2 94 mm Hg, PaCO2 31 mm Hg, and HCO3 26 mEq/L. Which question should the nurse ask when developing this clients plan of care?

A. Do you take any over-the-counter medications?
B. You appear anxious. What is causing your distress?
C. Do you have a history of anxiety attacks?
D. You are breathing fast. Is this causing you to feel light-headed?

Correct answer: B

Rationale:

4. Which condition can result from prolonged vomiting or diarrhea?

A. Intracellular fluid
B. Interstitial fluid
C. Dehydration
D. Electrolyte

Correct answer: C

Rationale: The correct answer is C: Dehydration. Prolonged vomiting or diarrhea can lead to significant fluid loss, causing dehydration. Intracellular fluid (choice A) and interstitial fluid (choice B) refer to specific compartments of body fluid and are not conditions resulting from vomiting or diarrhea. Electrolytes (choice D) are minerals that help maintain fluid balance in the body but are not the condition directly resulting from prolonged vomiting or diarrhea.