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: 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: A

Rationale: The correct answer is A: Kidney, ureter, bladder (KUB) x-ray. This procedure is noninvasive and commonly used to assess kidney function by visualizing the size, shape, and position of the kidneys. Renal ultrasound is also noninvasive and can provide detailed images of the kidneys. However, MRI and IVP are more invasive procedures that involve the use of contrast agents and are not typically used solely for diagnostic purposes to assess kidney function. Overall, KUB x-ray and renal ultrasound are the preferred noninvasive options for evaluating kidney function.

Correct Answer: A

Rationale: The correct answer is A. A decrease in the arterial pressure (hypotension) with a low diastolic pressure (46 mmHg) may indicate inadequate perfusion, possibly due to inadequate cardiac output from the mechanical ventilation. This suggests that a change in ventilator settings may be required to improve oxygenation and perfusion. Option B is incorrect because a heart rate of 58 beats/minute alone does not provide direct information on the patient's hemodynamic status. Option C is incorrect as an increased stroke volume would usually be a positive indicator; it does not necessarily indicate a need for changing the ventilator settings. Option D is incorrect as a stroke volume variation of 12% is within normal limits and does not necessarily require a change in ventilator settings.

Correct Answer: B

Rationale: The correct answer is B: Abdominal ultrasonography. This is because ultrasonography is a non-invasive imaging technique that can quickly evaluate for internal injuries such as organ damage or bleeding in patients with blunt abdominal trauma. It is a rapid and effective diagnostic tool to assess the extent of injury and guide further management. Peritoneal lavage (A) is an invasive procedure used in trauma settings to detect intra-abdominal bleeding but is not typically used for teaching purposes. Nasogastric tube placement (C) is used for decompression and drainage in certain conditions but is not relevant for assessing abdominal trauma. Magnetic resonance imaging (MRI) (D) is not typically used as the initial imaging modality for acute trauma due to time constraints and its limited availability in emergency settings.