Incidence of and factors associated with hyponatremia in traumatic cervical spinal cord injury patients

Retrospective study.To investigate the incidence of and factors associated with hyponatremia among traumatic cervical spinal cord injury (SCI) patients.Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.This retrospective study included traumatic cervical SCI patients that were admitted to the Siriraj Spinal Unit during January 2002 to May 2013. Patient demographic and clinical data were collected.One hundred and twenty-three patients (98 males, 25 females) were enrolled. The mean age of patients was 47.2 ± 16.9 years (range: 11-84). There were 38 complete and 85 incomplete cord injuries. Seventy-six patients were treated surgically, and all others received conservative treatment. Hyponatremia developed in 54 patients (43.9%), and 74.1% of all cases of hyponatremia presented within 9 days after SCI. Hyponatremia occurred on the first day in 10 patients (18.5%), on the fifth day in 6 patients (11.1%), and on the eighth day in 5 patients (9.26%). Hyponatremia occurred in 6/10 patients (60.0%) with upper cervical spine injury (C1-2), and in 48/113 patients (42.5%) with lower cervical spine injury (C3-7) (odds ratio [OR]: 2.031, 95% confidence interval [CI]: 0.543-7.596; p = 0.292). The incidence of hyponatremia was 65.8% in complete SCI patients, and 34.1% in incomplete SCI patients. Logistic regression analysis revealed complete SCI to be the only factor significantly associated with hyponatremia (OR: 3.714, 95% CI: 1.658-8.317; p < 0.001).Hyponatremia was found to be common in post-traumatic cervical SCI patients. Complete SCI was identified as the only factor significantly associated with hyponatremia in traumatic cervical SCI patients.