Correct Answer: B

Rationale: The correct answer is B: Anxiety-induced hyperventilation. The arterial blood gas values show a pH of 7.48 (alkalosis) with low PaCO2 (respiratory alkalosis), which is consistent with hyperventilation due to anxiety. HCO3 is within normal range, ruling out metabolic causes. A: Diarrhea and vomiting would lead to metabolic acidosis with low pH and decreased HCO3. C: COPD would typically present with respiratory acidosis (high PaCO2) and normal to high HCO3. D: Diabetic ketoacidosis and emphysema would show metabolic acidosis with low pH and low HCO3.

Correct Answer: A

Rationale: The correct answer is A: Substantially reduced renal function. In older adults, elevated serum creatinine levels can indicate impaired kidney function, as the kidneys may not filter waste products as efficiently. This can lead to a buildup of creatinine in the blood. Acute kidney injury (Choice B) is a sudden decline in kidney function and would typically present with a more significant increase in creatinine levels. Decreased cardiac output (Choice C) would not directly cause elevated creatinine levels. Alterations in the ratio of body fluids to muscle mass (Choice D) would not be a common cause of elevated creatinine levels in this scenario.

Correct Answer: C

Rationale: The correct answer is C: Inelastic skin turgor is a normal part of aging. As people age, their skin loses elasticity and becomes less turgid, which can affect skin turgor assessment. Skin turgor assessment is an important indicator of hydration status, and in older adults, it is normal for the skin to be less elastic. This is due to changes in collagen and elastin fibers in the skin with aging. Choices A, B, and D are incorrect because overhydration is not common among healthy older adults, dehydration causes the skin to appear tented rather than spongy, and skin turgor can still be assessed in patients over 70, although it may be less reliable due to natural changes in skin elasticity with aging.

Correct Answer: A

Rationale: The correct answer is A: "Avoid carrying your grandchild with the arm that has the central catheter." This is important because carrying a child can put strain on the arm where the catheter is inserted, increasing the risk of dislodging or damaging the catheter. It is crucial to protect the integrity of the catheter site to prevent complications such as infection or bleeding. Choice B is incorrect because placing the arm with the central catheter in a sling during the day is unnecessary and could restrict the client's mobility and lead to discomfort. Choice C is incorrect because flushing the PICC line with normal saline should be done by a healthcare professional and not the client themselves. Choice D is incorrect because using the arm with the central catheter for most activities of daily living can increase the risk of accidental dislodgment or damage to the catheter. It is important to be cautious and limit certain activities to protect the catheter and maintain its function.

Correct Answer: A

Rationale: The correct answer is A because electrolyte-free water, such as sterile water, can rapidly enter red blood cells due to osmotic differences, causing them to swell and potentially rupture, leading to hemolysis. This can result in severe harm to the patient. Choice B is incorrect because electrolyte-free water is not indicated for severely dehydrated patients with neurologic signs and symptoms. They require electrolytes to correct their imbalances. Choice C is incorrect as administering electrolyte-free water would not address excess calcium and/or magnesium ions in the body. Specific treatments for hypercalcemia or hypermagnesemia are needed. Choice D is incorrect because patients with fluid deficits due to renal failure require electrolyte-balanced solutions to manage their condition effectively. Electrolyte-free water would not address the electrolyte imbalances associated with renal failure.