Final answer:
The nurse should report decreased urine output to the provider, as it may indicate dehydration or acute kidney injury. Weight loss and stable vital signs are expected findings, and relief of nausea is a positive sign.
Step-by-step explanation:
A nurse caring for a client with hyperemesis who is receiving IV fluid replacement should monitor for several important clinical signs. Of the options provided, the nurse should report decreased urine output to the provider. This symptom suggests the possibility of dehydration, which can be a consequence of excessive vomiting and fluid loss. Decreased urine output, which may be related to oliguria, can also indicate acute kidney injury or worsening dehydration, both of which require immediate medical attention. Weight loss and relief of nausea are expected findings in a patient with hyperemesis, and stable vital signs are generally a positive sign of stability.