MSFinals-6100

MSFinals-6100

A 49-year-old woman presents to the emergency department with a 6 day history of severe vomiting and diarrhoea after returning from a recent trip to Africa. She reports feeling weak and lethargic, and has been struggling to keep down food and drink.

Upon initial assessment, she presents with dry mucous membranes, reduced skin turgor, cool extremities, and a non-visible jugular venous pressure. She is producing dark brown urine and is clinically oliguric over a 24-hour measurement.

Her initial blood tests reveal elevated levels of urea and creatinine: Urea 33 mmol/L (2.0 – 7.0) and Creatinine 320 µmol/L (55 – 120). She is given fluid therapy and antibiotic treatment for her gastroenteritis.

Three days later, she appears clinically rehydrated and is apyrexial, but still oliguric. However, her blood tests reveal further deterioration: Urea 39 mmol/L (2.0 – 7.0) and Creatinine 510 µmol/L (55 – 120). Urinalysis and microscopy reveals muddy brown granular casts.

What is the underlying cause of her worsening urea and creatinine levels?