Analysis of risk factors for hyponatremia in patients with acute spinal cord injury: a retrospective single-institution study in Japan.

Retrospective single-institution observational study. Spinal cord injury (SCI) is associated with a high prevalence of hyponatremia, which can cause various clinical symptoms and increase mortality. We aimed to analyze the risk factors for hyponatremia in patients with acute SCI. Trauma Center, Tohoku University Hospital, Japan METHODS: We reviewed the medical records of patients with SCI admitted between January 2008 and November 2016. Least angle regression analyses was performed to assess the association between hyponatremia and other parameters. Of the 213 enrolled patients, 85 (40%) had hyponatremia (serum Na < 135 mmol/L) whilst 19 (9%) had severe hyponatremia (serum Na < 130 mmol/L). Least angle regression analyses revealed that hyponatremia was significantly associated with higher American Spinal Injury Association impairment scale, nosocomial pneumonia, deep vein thrombosis, bradycardia, and surgery for SCI before developing hyponatremia. Severe hyponatremia was significantly associated with traumatic brain injury with an abbreviated injury scale score ≥3, higher American Spinal Injury Association impairment scale, bradycardia, vasopressors, and nosocomial pneumonia. Various factors including traumatic brain injury with an abbreviated injury scale score ≥3 and higher American Spinal Injury Association impairment scale may be associated with hyponatremia in patients with acute SCI. These factors can help clinicians identify and monitor SCI patients with a higher hyponatremia risk, and potentially help patients to avoid severe complications.