22nd May 2025

A 60-year-old man is brought to ED by ambulance.

A 60-year-old man is brought to ED by ambulance. He has been unwell for 4 days with vomiting and diarrhoea. His wife called the ambulance today as he has been unable to get out of bed and unable to keep any fluids down. He is generally fit and well, with a past medical history of diet controlled type 2 diabetes mellitus. He is on no regular medications. 

His wife has accompanied him to the hospital, and tells you that he has also been seeing “strange people” in the bedroom over the last 2 days. He has passed very little urine over the last 24 hours. 

On review, he has a GCS of 13 (E3V4M6), and is slightly tachypnoeic. His blood pressure is 79/58, and his HR is 123. His mucus membranes are dry, his chest is clear, and his abdomen is generally soft with mild discomfort on palpation. His JVP is not visible, and there is no peripheral oedema. 

Initial bloods are: WCC 18.3, Hb 147, Plt 502, Na 118, K+ 3.2, Urea 12.5, Creat 149 (baseline 90). 

What is the next best step in this patient’s management? Please select only ONE answer.