The practical nurse (PN) is caring for an older client who is receiving chemotherapy for lung cancer. Which finding is the highest priority for the PN to report to the charge nurse? Reference ranges: Blood urea nitrogen (BUN): [Adult: 10 to 20 mg/dL or 3.6 to 7.1 mmol/L] Platelets: [150,000 to 400,000/mm3 or 150 to 400 x 10^9/L]

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: 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. 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. 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.