Final answer:
For a PVR test, a patient should be instructed to notify the nurse immediately after voiding. PVR measures the urine remaining in the bladder, and there's generally no need to avoid liquids before the test.
Step-by-step explanation:
The instruction a nurse should provide to a patient scheduled for a postvoid residual (PVR) test is to call the nurse immediately after voiding. Therefore, the correct answer is a. Call the nurse immediately after voiding.
A PVR test measures the amount of urine left in the bladder after voiding. The purpose of the test is to determine if there is any urinary retention, which can be indicative of various bladder or urethral issues. Patients typically do not need to avoid fluids before the test, and they should void normally into a toilet or receptacle rather than a flow meter for this specific test.
Regarding urine output after fluid intake, the kidneys start the process of increasing urine production, or diuresis, approximately 30 minutes after drinking a large glass of water. This process peaks about an hour after fluid intake and returns to normal after about 3 hours. Knowledge of this physiological response is essential when preparing a patient for urine-related tests.