Diagnostic criteria and clinical course of inappropriate antidiuresis and cerebral salt wasting syndrome following traumatic brain injury: A retrospective cohort of 351 severe trauma patients
Injury. 2026 Mar 22:113157. doi: 10.1016/j.injury.2026.113157. Online ahead of print.
ABSTRACT
BACKGROUND: Hyponatremia is common in traumatic brain injury (TBI) population, and is associated with poor outcomes. The main mechanisms are the syndrome of inappropriate antidiuresis (SIAD) and cerebral salt wasting syndrome (CSW). This study aimed to assess hyponatremia prevalence and time of onset in patients with TBI and assess differences between SIAD and CSW.
METHOD: This retrospective cohort study was conducted between 2015 and 2018 in our level 1 trauma center. Patients admitted to the intensive care unit with TBI were included. Three subgroups were determined using urinary clinical and biological criteria: SIAD, CSW, and Undetermined. Predictive factors were assessed for each subgroup, especially the influence of free water, sodium, or fluid intake.
RESULTS: Among 351 trauma patients with TBI, 57 (16 % [95 %CI 12 %20 %]) developed hyponatremia within 30 days. 30 (9 % [95 %CI 6 %12 %]) developed a SIAD, 13 (4 % [95 %CI 2 %6 %]) a CSW, 14 (4 % [95 %CI 2 %6 %]) an undetermined form. CSW subgroup had higher Simplified Acute Physiology Score II (SAPS II), Injury severity score ISS, more cerebral injuries, intracranial pressure monitoring, mechanical ventilation than the SIAD subgroup. Fluid, sodium and free water intake in the 48 h preceding hyponatremia did not influence CSW or Undetermined hyponatremia development, whereas excessive free water intake in the 48 h preceding hyponatremia was associated with SIAD development.
CONCLUSION: Hyponatremia prevalence was 16 %, half were SIAD and one quarter were CSW. Patients with CSW were more severely injured than those who developed SIAD. Excessive free water intake could induce more SIAD-related hyponatremia due to impaired urine dilution.
LEVEL OF EVIDENCE: III, prognostic/epidemiological.
PMID:41927419 | DOI:10.1016/j.injury.2026.113157












