1. Incidence, Risk Factors, and Short-Term Outcomes Associated with Hyponatremia in the Guillain-Barré Syndrome: A Nationwide Analysis of Hospitalizations in the United States Kavelin Rumalla 1, Adithi Y. Reddy 1, Manoj K. Mittal 2 1 University of Missouri-Kansas City School of Medicine, 2 University of Kansas Medical Center, Department of Neurology ★ The incidence of hyponatremia among 54,778 patients hospitalized for GBS between 2002 and 2011 was 11.8% compared to the non-GBS incidence of 4.0% in the NIS. ★ Hyponatremia incidence was independently impacted by a number of risk factors, namely, increasing age, Medicaid insurance status, type of treatment, and preexisting comorbidity. ★ In a multivariate analysis, adjusting for other risk factors, patients who developed hyponatremia were 84% more likely to suffer 1 or more complications (OR: 1.84, 95% CI: 1.72-1.96), 88% more likely to face prolonged LOS (OR: 1.88, 95% CI: 1.73-2.05), 129% more likely to incur increased total costs (OR: 2.29, 95% CI: 2.10-2.50), 140% more likely to suffer an adverse discharge (OR: 2.40, 95% CI: 2.21-2.60), and 26% more likely to die during hospitalization (OR: 1.26, 95% CI: 1.06-1.49). ★ We hypothesize that the increasing incidence of hyponatremia in GBS over the past decade may have been influenced by the increased use of IVIG as a standard treatment for GBS ★ This study was retrospective and cannot imply causality. Thus, we encourage the design of future studies of prospective nature to confirm the results reported in our study.. ★ 1. Upadhyay A, Jaber BL, Madias NE. Incidence and prevalence of hyponatremia. Am J Med 2006;119(7 Suppl 1):S30– ★ 2. Yuki N, Hartung H-P. Guillain-Barre syndrome. N Engl J Med 2012;366(24):2294–304. ★ 3. Colls BM. Guillain-Barre syndrome and hyponatraemia. Intern Med J 2003;33(1-2). ★ 4. Kloesel B, Hickson LJ. Severe hyponatremia as the initial sign preceding guillain-barre syndrome, an acute inflammatory demyelinating polyneuropathy: a case report. Case Rep Neurol Med 2013;2013. ★ 5. Elixhauser A et al.. Comorbidity measures for use with administrative data. Med Care. 1998;36(1). INTRODUCTION METHODS RESULTS: INCIDENCE AND RISK FACTORS CONCLUSION REFERENCES ★ Hyponatremia is the most common electrolyte abnormality detected in hospitalized patients and often arises as a complication of an acute illness. 1 ★ The Guillain-Barré Syndrome (GBS) is a rapidly progressive autoimmune disorder characterized by acute paralysis and loss of reflexes. 2 ★ Anecdotal evidence in the form of case reports suggest a possible relationship between GBS and hyponatremia. 3-4 ★ We sought to investigate this epidemiological relationship by studying the incidence, risk factors, and outcomes of hyponatremia in GBS. ★ Study Population: ○Design: Retrospective administrative data analysis ○Data source: Nationwide Inpatient Sample, 2002-2011 ○Inclusion criteria: ■ GBS: ICD-9-CM 1º diagnosis code 357.0 ■ Hyponatremia: ICD-9-CM 2º diagnosis code 276.1 ○Exclusion criteria: ■ Younger than 18 years of age ■ Other existing polyneuropathies ★ Variables ○Patient demographics → age, gender, race, insurance status ○Pre-existing comorbidity → 31 total (Elixhauser et al.) 5 ○Hospital type → location, bedsize, teaching status, admission day ○In-hospital treatment → intravenous immunoglobulin (IVIG), plasma exchange (PLEX) ○Discharge outcomes → complication occurrence, mean total hospital costs, mean length of stay (LOS), adverse discharge disposition, and in- hospital mortality ★ Statistical Analysis ○SPSS V23 software was used for all analyses. ○Alpha was set at P<0.01 ○The effect of patient demographics, pre-existing comorbidity, hospital type, and in-hospital procedures on the occurrence of hyponatremia and the impact of hyponatremia occurrence on in-hospital outcomes was explored in both bivariate and multivariable analyses. ○Only variables with P<0.01 in the bivariate analysis were entered in the corresponding multivariable model. RESULTS: OUTCOMES Multivariable Analysis: Predictors of Hyponatremia