The patient's potassium level is 7.0 mEq/L. Besides dialysis, which of the following actually reduces plasma potassium levels and total body potassium content safely in a patient with renal dysfunction?

Correct Answer: A

Rationale: The correct answer is A: Sodium polystyrene sulfonate. It works by exchanging sodium ions for potassium ions in the intestine, reducing plasma potassium levels. Step 1: Administering sodium polystyrene sulfonate orally or rectally. Step 2: It binds with potassium in the gut, leading to fecal elimination. Step 3: This process helps lower both plasma potassium levels and total body potassium content safely. Choices B, C, and D are incorrect. B: Sodium polystyrene sulfonate with sorbitol can cause intestinal necrosis. C: Regular insulin temporarily shifts potassium into cells but doesn't reduce total body potassium. D: Calcium gluconate only stabilizes cardiac membrane potential without reducing potassium levels.

Correct Answer: C

Rationale: The correct answer is C because administering furosemide 40 mg IV push is the priority intervention for a patient with symptoms of fluid overload, such as weight gain, edema, and crackles. Furosemide is a potent diuretic that will help reduce fluid volume in the body, including the lungs, improving respiratory status. Weighing the patient, fluid restriction, and maintaining accurate intake and output records are important but secondary interventions compared to addressing the immediate issue of fluid overload. Options A and B do not provide a clear rationale for their choices, making them incorrect. Option D is incomplete.

Correct Answer: C

Rationale: Renal function does not represent a possible source of input for the internal body pool because it refers to the excretory system's function of filtering waste and excess substances from the blood, rather than introducing substances into the body. Inhalation introduces gases or particles into the body through the respiratory system. Intravenous injection delivers substances directly into the bloodstream. Absorption through the skin allows substances to enter the body through the skin barrier. Renal function involves filtering and eliminating substances from the body, making it the only choice that does not add to the internal body pool.

Correct Answer: C

Rationale: The correct answer is C: ethnicity. Body water content is primarily determined by physiological factors, such as sex, age, and body composition. Ethnicity does not directly affect body water content as it is not a physiological factor. Sex can influence body water content due to hormonal differences, age affects it due to changes in body composition and metabolism, and body composition, such as muscle mass and fat percentage, can also impact body water content. Therefore, ethnicity is the factor that does NOT determine body water content.

Correct Answer: B

Rationale: The correct answer is B (25 percent) because plasma constitutes around 20-25% of extracellular fluid. Plasma is the liquid component of blood and is part of the extracellular fluid. Option A (0 percent) is incorrect because plasma does make up a percentage of extracellular fluid. Option C (50 percent) and Option D (75 percent) are incorrect as they overestimate the percentage of extracellular fluid that plasma constitutes. Plasma, while important, is only a portion of the extracellular fluid in the body.