5th May 2024

A 72-year-old woman with a history of diabetes and hypertension presents with nausea and decreased urine output for two days.

A 72-year-old woman with a history of diabetes and hypertension presents with nausea and decreased urine output for two days. She mentions taking ibuprofen frequently for chronic knee pain. Her blood pressure is 110/70 mmHg, and her physical examination is unremarkable apart from mild pedal edema. Laboratory tests reveal:

Sodium: 139 mmol/L (135–145)

Potassium: 5.6 mmol/L (3.5–5.1)

Urea: 16.5 mmol/L (2.5–7.8)

Creatinine: 176 μmol/L (45–90)

eGFR: 30 mL/min/1.73m² (>90)

Urinalysis shows trace protein and no blood. The most likely diagnosis is acute kidney injury (AKI) possibly related to hypovolaemia and NSAID use.

Which of the following is the most appropriate initial management?