ATI RN
Fluid and Electrolytes ATI
1. 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.
2. A nurse admitting a patient with a history of emphysema reviews her past lab reports and notes that the patient's PaCO2 has been 56 to 64 mmHg. The nurse will be cautious administering oxygen because:
- A. The patient's calcium will rise dramatically due to pituitary stimulation.
- B. The oxygen will increase the patient's intracranial pressure and create confusion.
- C. The oxygen may cause the patient to hyperventilate and become acidotic.
- D. Using oxygen may result in the patient developing carbon dioxide narcosis and hypoxemia.
Correct answer: D
Rationale: When PaCO2 chronically exceeds 50 mm Hg, it creates insensitivity to CO2 in the respiratory medulla, and the use of oxygen may result in the patient developing carbon dioxide narcosis and hypoxemia. Choice A is incorrect because administering oxygen does not lead to a dramatic rise in calcium due to pituitary stimulation. Choice B is incorrect because administering oxygen does not directly increase intracranial pressure or create confusion. Choice C is incorrect because administering oxygen to a patient with emphysema and high PaCO2 levels is more likely to cause respiratory depression than hyperventilation and acidosis.
3. Where is the largest volume of water in the body located?
- A. Plasma
- B. The fluid inside the cells
- C. Interstitial fluid
- D. Lymph
Correct answer: B
Rationale: The correct answer is B. The largest volume of water in the body is found inside the cells, known as intracellular fluid. This fluid makes up the majority of the body's total water content. Choices A, C, and D are incorrect because while plasma, interstitial fluid, and lymph are important components of the body's fluid compartments, they do not contain the largest volume of water in the body.
4. The nurse is caring for a patient who is diaphoretic from a fever. The amount of sodium excreted in the urine will:
- A. Decrease
- B. Increase
- C. Remain unchanged
- D. Fluctuate
Correct answer: A
Rationale: Increased sweating (diaphoresis) causes the loss of sodium and other electrolytes from the body. As a result, the body tries to conserve sodium, leading to a decrease in the amount of sodium excreted in the urine. Choice B is incorrect because increased sweating results in sodium loss, not retention. Choice C is incorrect because with increased sweating, there is a need to conserve sodium, leading to a decrease in its excretion. Choice D is incorrect as there is a clear physiological response to sweating that results in a more consistent decrease in sodium excretion.
5. What is the fluid that surrounds the cells called?
- A. plasma
- B. interstitial fluid
- C. intracellular fluid
- D. edema
Correct answer: B
Rationale: The correct answer is interstitial fluid. Interstitial fluid is the fluid that surrounds and fills the spaces between cells, facilitating nutrient and waste exchange. Plasma, referred to in choice A, is the liquid part of blood. Choice C, intracellular fluid, is the fluid inside cells. Choice D, edema, is an abnormal accumulation of fluid in interstitial spaces, causing swelling.
Similar Questions
Access More Features
ATI RN Basic
$69.99/ 30 days
- 5,000 Questions with answers
- All ATI courses Coverage
- 30 days access
ATI RN Premium
$149.99/ 90 days
- 5,000 Questions with answers
- All ATI courses Coverage
- 30 days access