A 70 year old man is 4 hours post right heme-colectomy for a tumor.

A 70 year old man is 4 hours post right heme-colectomy for a tumor. The NP is called due to falling urine output since surgery.

Past medical history – hypertension, type 2 diabetes, gout

Medications – lisinopril, allopurinol, and spironolactone (all last given this morning).

Physical exam – BP 100/60. HR 110 regular weight 60 kg

Lungs are clear, abdominal wound is clean with no drainage, No JVD

Urine output

1700 hr. 35 ml

1800 hr 22 ml

1900 hr 15 ml

2000 hr. 8 ml

Urine dipstick is normal

How would you classify his renal status? How would you treat it?