A study of predictors for hyponatraemia in patients with cervical spinal cord injury.

STUDY DESIGN

A retrospective study.

OBJECTIVES

The objectives of the study were to investigate the predictors for hyponatraemia in patients with cervical spinal cord injuries (CSCIs) and to define the relationship between magnetic resonance imaging (MRI) scans and hyponatraemia.

SETTING

The study was carried out at The First Affiliated Hospital of Anhui Medical University.

METHODS

A total of 292 patients with CSCIs were retrospectively reviewed to determine the predictors of hyponatraemia. Fourteen variables were extracted from the medical records: age, sex, blood pressure (BP), tracheostomy, serum potassium, serum chloride, serum bicarbonate, serum albumin, intravenous fluid intake and urine volume for 24 h, haematocrit, haemoglobin, neurological assessment and four MRI signal patterns. Univariate and multivariate analyses were used to determine the effect of each variable on hyponatraemia.

RESULTS

Eighty-two of the 270 patients (30%) developed hyponatraemia. Univariate analyses indicated that the following variables were significant predictors of hyponatraemia: tracheostomy; the initial American Spinal Injury Association (ASIA) Impairment Scale (AIS) A assessment; and haemorrhage changes on T2-weighted MRI scans, and low BP. Multivariate regression analyses revealed two variables were significant predictors of hyponatraemia: haemorrhage changes on T2-weighted MRI scans and low BP.

CONCLUSIONS

Haemorrhage changes on MRI scans were closely associated with the onset of hyponatremia and could provide objective data for forecasting hyponatraemia in CSCI patients. Low BP was also a reasonable predictor of hyponatremia.