Case of the Month #6 - Diabetes Insipidus (DI)

Published 03/02/2022


An unresponsive 76-year-old male is admitted to the intensive care unit.  He has a past medical history of bipolar affective disorder (treated with lithium and valproate), self-harm and previous suicide attempts. 

His bloods show an acute on chronic kidney injury with polyuria (100-330ml/hr) and an eGFR of 15.  Serum sodium is  165mmol/L.  Plasma and urine osmolalities were measured: 

Plasma osmolality – 356 mOsmol/kg

Urine osmolality – 231 mOsmol/kg


Written by Dr Laura Kocierz

First published on 18 June 2020