Critical Care Nursing Cardiac Questions

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 because during terminal weaning, the artificial ventilation is discontinued while maintaining the artificial airway to ensure comfort and support. This allows the patient to breathe on their own with support as needed. Explanation: 1. Option A: Complete extubation following ventilator withdrawal may not be suitable during terminal weaning as it involves removing the breathing tube entirely. 2. Option C: Discontinuation of anxiolytic and pain medications may not always be appropriate during terminal weaning as it depends on the patient's comfort needs. 3. Option D: Titration of ventilator support based on blood gas determinations is not typically done during terminal weaning as the focus is on gradual withdrawal of ventilation support while maintaining comfort.

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: C

Rationale: The correct answer is C because it explains that the decision to remove life-sustaining treatments is based on the fact that these treatments are not helping the patient and may actually be causing discomfort. This rationale aligns with the principle of beneficence, which emphasizes doing good and avoiding harm to the patient. It also respects the patient's autonomy by prioritizing their well-being and quality of life. Choice A is incorrect as it focuses on financial reasons rather than the patient's best interest. Choice B is incorrect because it prioritizes hospital resources over individual patient care. Choice D is incorrect as it lacks clarity and may come across as insensitive to the significant other's concerns.