A client with chronic kidney disease reports to the nurse of feeling increasingly tired. The client receives injections for epoetin alfa three times a week. Which laboratory value should the nurse review?

A high blood urea nitrogen (BUN) level indicates impaired renal function, which can be caused by dehydration, infection, or nephrotoxic drugs. Chemotherapy can damage the kidneys and increase the risk of renal failure. The PN should report this finding to the charge nurse, as it may require fluid replacement, dose adjustment, or discontinuation of the chemotherapy.

The other options are not correct because:

1. Periodic nausea and vomiting are common side effects of chemotherapy that can be managed with antiemetics, hydration, and dietary modifications. They are not as urgent as a high BUN level.
2. Decreased deep tendon reflexes may indicate hypocalcemia, hypomagnesemia, or peripheral neuropathy, which can be caused by chemotherapy or other factors. They are not as urgent as a high BUN level.
3. A platelet count of 135,000/mm3 or 135 x 10^9/L is slightly below the normal range, but not significantly low. Chemotherapy can cause thrombocytopenia, which increases the risk of bleeding. The PN should monitor the client for signs of bleeding, but this finding is not as urgent as a high BUN level.

- A bowel pattern is the frequency, consistency, and appearance of a person's bowel movements. A normal bowel pattern is what's normal for each person, and it can vary depending on factors such as diet, age, physical activity, and health conditions.

- A focused gastrointestinal system assessment includes collecting subjective data about the patient's history of gastrointestinal disease, signs and symptoms of gastrointestinal problems, diet and nutrition, and bowel patterns. It also includes inspecting and auscultating the abdomen for any abnormalities.

- When a client reports having a bowel movement three days ago, the first action that the practical nurse should implement is to determine the client's usual bowel pattern. This will help to evaluate if the client is experiencing constipation or if this is their normal frequency. It will also help to identify any changes or risk factors that may affect the client's bowel function.

Therefore, option B is the correct answer, while options A, C, and D are incorrect.

Option A is incorrect because administering a stool softener without assessing the client's bowel pattern may not be appropriate or effective.

Option C is incorrect because encouraging ambulation may help to stimulate bowel activity, but it is not the first action to take.

Option D is incorrect because recommending dietary changes may be helpful for preventing or treating constipation, but it is not the first action to take.