Risk factor analysis for low blood pressure and hyponatremia in acutely and subacutely spinal cord injured patients

Abstract

Study design: Case control. Objective: To clarify the predictors of low blood pressure (BP) and hyponatremia after spinal cord injury (SCI) and to discuss their pathophysiology. Setting: A SCI center in Japan. Methods: Age, gender, initial ASIA impairment scale (AIS) score, BP, blood electrolytes (sodium, K and Cl) and biochemical markers were evaluated at 1 month after injury. Risk factors of low BP and hyponatremia were analyzed using uni- and multivariate logistic regression models. Results: This study comprised of 172 SCI patients. Initial AIS score (Odds ratio (OR): 1.24, 95% confidence intervals (CI) 1.13-1.49, P-value <0.01) and hyponatremia (OR: 3.71, 95%CI 1.27-6.96, P<0.01) were the most important risk factors of low BP. As a second step, risk factors of hyponatremia were initial AIS score (OR: 1.36, 95%CI 1.08-2.78, P<0.01) and age (OR: 1.55, 95%CI 1.17-2.93, P<0.01). Conclusions: In acute and subacute period, the more severe SCI and lower AIS score patients have the more frequently low BP and/or hyponatremia do appear. © 2012 International Spinal Cord Society All rights reserved.