Correct Answer: B

Rationale: The correct answer is B: Restlessness. When the body experiences hypoxemia (low oxygen levels), the brain is deprived of oxygen, leading to early signs such as restlessness. This is due to the brain's attempt to increase oxygen intake by increasing activity. Cyanosis (A) is a late sign of hypoxemia when oxygen levels are critically low. Tachycardia (C) and tachypnea (D) are compensatory mechanisms in response to hypoxemia, but they are not early signs affecting the nervous system directly.

Correct Answer: A

Rationale: The correct answer is A because writing DNR orders before discontinuation of life-sustaining treatments ensures clear communication and legal documentation of the patient's wishes. Choice B is incorrect as family support is essential in end-of-life care. Choice C is incorrect as DNR orders should be established before withdrawing treatment. Choice D is incorrect as the DNR order should be in place before shift change for immediate implementation if needed.

Correct Answer: D

Rationale: The correct answer is D, the 70-year-old mother with blood type A positive. This choice is the best candidate for evaluation due to her blood type matching the patient's (A positive) for kidney transplantation. Age and medical history are also crucial factors in determining suitability. The 65-year-old brother (choice A) has hypertension, a significant risk factor. The 35-year-old female (choice B) with food allergies may have potential complications. The 14-year-old son (choice C) is underage and might not be a suitable donor due to age and the potential impact on his growth and development. In summary, choice D aligns with the matching blood type and age, making the mother the most suitable candidate for evaluation.

Correct Answer: C

Rationale: Step-by-step rationale for why choice C is correct: 1. Intrapulmonary shunting refers to blood bypassing the normal oxygenation process in the lungs. 2. Choice C describes blood being shunted from the right side of the heart (deoxygenated blood) to the left side without oxygenation, leading to systemic circulation without oxygenation. 3. Choices A, B, and D do not accurately describe intrapulmonary shunting as they focus on other concepts like alveolar perfusion, heart failure, and unilateral lung blood supply, respectively.

Correct Answer: C

Rationale: The correct answer is C: intrarenal disease, probably acute tubular necrosis. The patient's symptoms of general malaise, fatigue, decreased urinary output, along with the presence of coarse, muddy brown granular casts and hematuria in the urinalysis indicate kidney damage. Acute tubular necrosis is a common cause of acute kidney injury characterized by damage to the renal tubules, leading to impaired kidney function. The presence of granular casts and hematuria suggests tubular injury and bleeding within the kidney. Choices A and B are incorrect as they refer to prerenal and postrenal causes of kidney injury, respectively, which do not align with the patient's symptoms and urinalysis findings. Choice D is incorrect as a urinary tract infection would typically present with different symptoms and urinalysis findings.