Correct Answer: B

Rationale: The correct answer is B: Place warm compresses on the site. Warm compresses can help increase blood flow, reduce pain, and promote healing at the site of inflammation. The warmth can help dilate blood vessels, increasing circulation to the area and promoting the removal of inflammatory substances. This can help alleviate pain and reduce swelling. Administering topical lidocaine (choice A) may not address the underlying cause of pain and redness. Administering oral pain medication (choice C) may be necessary for severe pain but may not directly address the local inflammation. Massaging the site with scented oils (choice D) can potentially introduce more irritants and should be avoided in cases of inflammation.

Correct Answer: D

Rationale: The correct answer is D: Presence of an ulnar pulse. This is the most important assessment to complete first because the presence of an ulnar pulse indicates adequate circulation in the hand, ensuring that the radial artery catheter is not compromising blood flow. If the ulnar pulse is absent, it may signify impaired circulation and potential complications such as ischemia. Choice A is incorrect because the amount of pressure in the fluid container is not directly related to the assessment of the radial artery catheter. Choice B is incorrect because the date of catheter tubing change is important for infection control but not the immediate priority in this situation. Choice C is incorrect as the percent of heparin in the infusion container is important for anticoagulation therapy but does not take precedence over assessing circulation in the hand.

Correct Answer: D

Rationale: The correct answer is D: Increased conservation of sodium. Older adults tend to have an increased conservation of sodium, leading to fluid retention and decreased fluid intake, which can contribute to dehydration. A: Decreased kidney mass is incorrect because it is a factor that can contribute to decreased kidney function but not directly linked to dehydration. B: Decreased renal blood flow can impact kidney function but is not a direct cause of dehydration in older adults. C: Decreased excretion of potassium is not a factor that directly contributes to dehydration in older adults.

Correct Answer: C

Rationale: Rationale: C is correct because in renal failure, the kidneys lose the ability to regenerate and reabsorb bicarbonate, which is essential for maintaining a stable pH level in the body. B is incorrect because the kidneys primarily regulate pH by controlling bicarbonate levels, not through electrolyte changes. A is incorrect because the kidneys do not regulate carbonic acid in the same way. D is incorrect as it does not accurately describe the process of pH regulation in the kidneys.

Correct Answer: B

Rationale: The correct answer is B because considering potential effects on the patient's mobility is crucial when selecting a site for IV insertion. Mobility can be affected if the IV is placed in a joint area or on the dominant hand. This could limit the patient's ability to move freely during and after the procedure. Therefore, it is important to choose a site that will not hinder the patient's movement. A: Choosing a hairless site is not the most important factor when selecting a site for IV insertion. C: Having the patient hold his arm over his head before insertion is not necessary and may cause discomfort for the patient. D: Leaving the tourniquet on for at least 3 minutes is not recommended as it can lead to complications such as venous stasis.