The nurse is caring for a patient following insertion of a left subclavian central venous catheter (CVC). Which action by the nurse best reduces th e risk of catheter-related bloodstream infection (CRBSI)?

Correct Answer: A

Rationale: The correct answer is A: Review daily the necessity of the central venous catheter. This action reduces the risk of CRBSI by promoting early removal of unnecessary catheters, which is a key strategy in preventing infections. Unnecessary catheters increase the risk of infection due to prolonged exposure to the patient's skin flora and possible contamination during insertion. Reviewing daily ensures the catheter is only kept when necessary, minimizing the duration of catheter use and reducing the chances of infection. Summary of other choices: B: Cleansing the insertion site daily with isopropyl alcohol is important for maintaining skin integrity but does not directly reduce the risk of CRBSI. C: Changing the pressurized tubing system and flush bag daily is important for maintaining catheter patency but does not directly reduce the risk of CRBSI. D: Maintaining a pressure of 300 mm Hg on the flush bag is important for proper catheter function but does not directly reduce the risk of CR

Correct Answer: B

Rationale: The correct answer is B: Avoid infusing vasoactive agents in the port used to obtain the TdCO measurement. This action ensures patient safety by preventing the introduction of vasoactive agents directly into the bloodstream during the measurement process. Infusing vasoactive agents can lead to inaccurate TdCO readings and potentially harm the patient. Choice A is incorrect because zero referencing the transducer system at the level of the phlebostatic axis is important for accurate pressure monitoring but not directly related to TdCO measurement safety. Choice C is incorrect as maintaining a pressure of 300 mm Hg on the flush solution bag is not directly related to the safety of TdCO measurement. Choice D is incorrect as limiting the length of noncompliant pressure tubing is important for accurate pressure readings but not directly related to the safety of TdCO measurement.

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: C

Rationale: Rationale: 1. Acute tubular necrosis (ATN) is the most common intrarenal condition as it directly affects kidney tubules. 2. ATN is characterized by damage to renal tubular cells due to various factors like toxins or ischemia. 3. Prolonged ischemia (choice A) can lead to ATN but is not the most common intrarenal condition. 4. Exposure to nephrotoxic substances (choice B) can cause ATN, but ATN itself is more common. 5. Hypotension for several hours (choice D) can result in ischemia and subsequent ATN, but ATN is still the primary intrarenal condition.

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.