SIADH and hyponatremia

Author: Jan Hudec, Miriam Šipošová, Kristýna Chudjáková

Institution: Faculty of Medicine at Masaryk University in Brno

Medical discipline: Emergency Medicine

Keywords: SIADH | hyponatremia | head injury

Educational evel: Undergraduate level | Graduate

The syndrome of inapropriate secrection of the ADH – antidiuretic hormone develops after injuries, operations or brain infections. Secretions of the ADH in organism results in water retention and also decreasing of plasma sodium level. However there are also other causes of hyponatremia, which differ significantly in their clinical solution. That is why it’s so important for the doctor to find the cause of hyponatremia as soon as possible and suggest correct therapy. This algorithm guides you in differential diagnosis of hyponatremia and folowing possibilities of the therapy.

Go to


Hyponatremia is one of the most common laboratory deviations which can occur in critically ill patients. It is connected with higher morbidity and mortality so it is important to identify the right cause of this condition as fast as possible. This algorithm emphasizes the importance of discovering plasma and urine osmolality level, urine sodium level and also the possibility to consider extracellular plasma volume.  After the correct diagnostic process this algorithm leads through the therapy of hyponatremia with orientation to the therapy of SIADH according to the european guidelines.

publikováno: 1. 7. 2018 | last modified on: 28. 5. 2020