Final answer:
The nurse should ensure the child has a full bladder and inform her that the renal ultrasound is a discomfort-free procedure. The correct option is C.
Step-by-step explanation:
When preparing an 8-year-old girl for a renal ultrasound, the nurse should include in the plan of care to ensure that the child has a full bladder for the test. This is important because a full bladder provides better imaging of the urinary tract structures and can help with the accuracy of the ultrasound. It is also important to inform the child that she should feel no discomfort during the procedure.
Unlike procedures that involve ionizing radiation, ultrasounds do not hurt and are noninvasive. Checking for allergies to shellfish is relevant for certain types of contrast dyes used in other imaging tests, but not for a standard ultrasound. Withholding food and fluids after midnight is not typically required for a renal ultrasound unless specified by the healthcare provider.