Renin plays a role in blood pressure regulation by

Correct Answer: A

Rationale: The correct answer is A because renin activates the renin-angiotensin-aldosterone cascade, which ultimately leads to vasoconstriction, increased blood pressure, and aldosterone release to increase sodium and water reabsorption. Renin does not suppress angiotensin production (B), decrease sodium reabsorption (C), or inhibit aldosterone release (D), as these actions would counteract its role in blood pressure regulation.

Correct Answer: D

Rationale: The correct answer is D because when a reliable 24-hour urine collection is not possible, a standardized formula can be used to estimate GFR. The Cockcroft-Gault equation or the Modification of Diet in Renal Disease (MDRD) equation are commonly used formulas to estimate GFR based on serum creatinine levels, age, gender, and race. These formulas provide a reasonable estimation of kidney function in the absence of a 24-hour urine collection. Choice A is incorrect because there are alternative methods available to estimate GFR. Choice B is incorrect because BUN alone is not sufficient to accurately determine renal function. Choice C is incorrect because an elevated BUN/creatinine ratio is not a direct measure of GFR and may be influenced by factors other than kidney function, such as hydration status or liver function.

Correct Answer: B

Rationale: The correct answer is B: Assess the patient’s lungs. Rhabdomyolysis can lead to acute kidney injury due to myoglobin release from damaged muscle cells. IV fluids and mannitol are given to prevent kidney damage by promoting myoglobin excretion. Assessing the patient’s lungs is crucial to monitor for potential complications such as acute respiratory distress syndrome (ARDS) which can occur as a result of rhabdomyolysis. This assessment helps to ensure early detection and prompt intervention if respiratory issues arise. Summary of Incorrect Choices: A: Assess the patient’s hearing - This is not directly related to rhabdomyolysis or its treatment. C: Decrease IV fluids once the diuretic has been administered - Decreasing IV fluids can exacerbate kidney injury in rhabdomyolysis. D: Give extra doses before giving radiological contrast agents - Mannitol is not routinely given before radiological contrast agents in the context of rhabdomyolysis management.

Correct Answer: B

Rationale: The correct answer is B because after 5 days, the risk of infection increases. Evaluating the patient for signs and symptoms of infection is crucial for early detection and treatment. Choice A is incorrect because routine dialysis catheter changes are not necessary after only 5 days. Choice C is incorrect as percutaneous catheters are for short-term use. Choice D is incorrect as using the catheter for fluid administration may increase the risk of infection.

Correct Answer: D

Rationale: The correct answer is D because CRRT removes solutes and water slowly, which is beneficial for hemodynamically unstable patients. This slow removal allows for gradual fluid and electrolyte balance adjustments, reducing the risk of hemodynamic instability. A: Incorrect - A hemofilter is indeed used in CRRT, but this choice does not highlight the key difference between CRRT and intermittent hemodialysis. B: Incorrect - CRRT actually provides slower solute and water removal compared to intermittent hemodialysis. C: Incorrect - Diffusion does occur in CRRT, as it is a key mechanism for solute removal in the process. In summary, the key difference between CRRT and intermittent hemodialysis is the slow removal of solutes and water in CRRT, making choice D the correct answer.