Correct Answer: B

Rationale: The correct answer is B because evaluating the patient's serum creatinine for up to 72 hours after the procedure is crucial in detecting contrast-induced kidney injury. An increase in serum creatinine levels indicates impaired kidney function due to the contrast dye. This monitoring allows for early detection and intervention to prevent further kidney damage. Choice A is incorrect because a decrease in urine output is a late sign of kidney injury and may not be present in the early stages. Choice C is incorrect as a renal ultrasound is not typically used to detect contrast-induced kidney injury. Choice D is incorrect as postvoid residual volume assessment is not specific to detecting intrarenal injury related to contrast dye use.

Correct Answer: B

Rationale: The correct answer is B: Hypovolemia. When the ventilator settings are adjusted to treat hypoxemia by increasing FiO2 and PEEP, it can lead to increased oxygenation but also potentially decrease venous return to the heart, causing a decrease in blood pressure. This decrease in blood pressure is most likely due to hypovolemia, as the increased PEEP can increase intrathoracic pressure, reducing venous return and preload, leading to a decrease in cardiac output and subsequent decrease in blood pressure. This choice is the most likely cause as the other options (A: Decrease in cardiac output, C: Increase in venous return, D: Oxygen toxicity) do not directly correlate with the changes in ventilator settings described in the question.

Correct Answer: B

Rationale: The correct answer is B because after brain death is confirmed, maintaining perfusion and oxygenation of organs is crucial to ensure their viability for donation. This process allows organs to be retrieved in optimal condition during the operation. Choice A is incorrect because a signed donor card is not a legal mandate for organ retrieval. Choice C is incorrect as the healthcare proxy's consent is typically required for organ donation. Choice D is incorrect because life support is not immediately withdrawn upon brain death confirmation; instead, organ preservation measures are initiated.

Correct Answer: C

Rationale: The correct answer is C: Pulmonary vascular resistance (PVR). PVR is the most appropriate parameter to monitor in a patient with pulmonary hypertension as it directly reflects the resistance in the pulmonary circulation. A decrease in PVR indicates a reduction in the constriction of blood vessels in the lungs, suggesting improvement in pulmonary hypertension. Monitoring CVP (A) is more relevant in assessing fluid status, SVR (B) is more indicative of systemic vascular tone, and PAWP (D) is useful in assessing left-sided heart function, but they are not as specific to evaluating the effectiveness of treatment for pulmonary hypertension.

Correct Answer: B

Rationale: The correct answer is B because applying an insulin sliding scale method based on research is an example of evidence-based practice. This method is derived from scientific evidence and research studies, ensuring the best outcomes for the patient. The other choices lack the same level of evidence-based rationale: A is based on a protocol, which may not be evidence-based; C is a standard safety practice, not necessarily evidence-based; D is a decision based on hospital policy or practicality, not specifically evidence-based.