Final answer:
The next step would be to evaluate the cause of the patient's oliguria and hypotension. Further tests may be ordered to determine the underlying cause and appropriate treatment options.
Step-by-step explanation:
The next step would be to evaluate the cause of the patient's oliguria and hypotension. There could be several potential causes, including renal failure or dehydration. The physician may order further tests such as blood tests, urine tests, or imaging studies to determine the underlying cause. Treatment options will depend on the underlying cause identified through these investigations.