Systematic Use of DDAVP to Prevent Serum Sodium Overcorrection in Severe Hyponatremia

Inclusion Criteria:

• Adults ( ≥18 years)

• Current admission in ICU

• Severe hyponatremia defined by SNa <120 mmol/L in the presence of neurologicalsymptoms (seizures, stupor defined as Glasgow score < 12, or signs of brainherniation) or by SNa <115 mmol/L

• Normal or decreased extracellular fluid volume

Exclusion Criteria:

• Obvious increase of extracellular fluid volume (cirrhosis with ascites, congestiveheart failure, nephrotic syndrome);

• Hyponatremia caused by hyperglycaemia (> 30 mmol/L) or hypertriglyceridemia (10 g/L)or hyperproteinaemia (120 g/L)

• Severe acute kidney injury (KDIGO 3)

• Severe chronic kidney disease (eGFR <20 ml/min)

• Coronary patients well stabilized with trinitrine-based medicines

• Recent neurosurgery or traumatic brain injury

• Previous DDAVP or hypertonic fluid administration for the current episode of severehyponatremia

• SNa increased by 5 mmol or more between admission at hospital and randomisation (H0)

• Known contraindication to DDAVP

• Allergy

• Syndrome of inappropriate antidiuretic hormone secretion (SIADH)

• History of unstable angina and/or known or suspected heart failure.

• Willebrand disease type IIB

• Severe previous neurologic disability (Glasgow Outcome Scale: GOS < 3)

• Diabetes insipidus receiving DDAVP treatment

• Moribund state (patient likely to die within 24h)

• Need for invasive mechanic ventilation

• Enrolment to another interventional study (clinical trial on medicinal product,medical device and interventional research involving human participants notconcerning health product)

• Pregnancy or breastfeeding

• Subject deprived of freedom, subject under a legal protective measure

• No affiliation to any health insurance system

• Refusal to participate to the study (patient or legal representative or familymember or close relative if present)