Hyponatremia is an independent predictor of in-hospital mortality in spontaneous intracerebral hemorrhage.
OBJECTIVE
Hyponatremia is the most frequent electrolyte disturbance in critical care. Across various disciplines, hyponatremia is associated with increased mortality and longer hospital stay, yet in intracerebral hemorrhage (ICH) no data are available. This the first study that investigated the prevalence and clinical associations of hyponatremia in patients with ICH.


METHODS
This observational study included all consecutive spontaneous ICH patients (n=464) admitted during a 5-year period to the Department of Neurology. Patient characteristics, in-hospital measures, mortality, and functional outcome (90 days and 1 year) were analyzed to determine the effects of hyponatremia (Na<135 mEq/L). Multivariable regression analyses were calculated for factors associated with hyponatremia and predictors of in-hospital mortality.


RESULTS
The prevalence of hyponatremia on hospital admission was 15.6% (n=66). Normonatremia was achieved and maintained in almost all hyponatremia patients<48 hours. In-hospital mortality was roughly doubled in hyponatremia compared with nonhyponatremia patients (40.9%; n=27 versus 21.1%; n=75), translating into a 2.5-fold increased odds ratio (P<0.001). Multivariable analyses identified hyponatremia as an independent predictor of in-hospital mortality (odds ratio, 2.2; 95% confidence interval, 1.05-4.62; P=0.037). Within 90 days after ICH, hyponatremia patients surviving hospital stay were also at greater risk of death (odds ratio, 4.8; 95% confidence interval, 2.1-10.6; P<0.001); thereafter, mortality rates were similar.


CONCLUSIONS
Hyponatremia was identified as an independent predictor of in-hospital mortality with a fairly high prevalence in spontaneous ICH patients. The presence of hyponatremia at hospital admission is related to an increased short-term mortality in patients surviving acute care, possibly reflecting a preexisting condition that is linked to worse outcome due to greater comorbidity. Correction of hyponatremia does not seem to compensate its influence on mortality, which strongly warrants future research.
From the Departments of Neurology (J.B.K., T.B., B.V., D.S., M.K., H.B.H.) and Neuroradiology (H.L., S.P.K.), University of Erlangen-Nuremberg, Erlangen, Germany.
Joji B
JB
Kuramatsu
Tobias
T
Bobinger
Bastian
B
Volbers
Dimitre
D
Staykov
Hannes
H
Lücking
Stephan P
SP
Kloska
Martin
M
Köhrmann
Hagen B
HB
Huttner
D000368:Aged; D000369:Aged, 80 and over; D002543:Cerebral Hemorrhage / Q000453:epidemiology*; D015897:Comorbidity; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007010:Hyponatremia / Q000097:blood / Q000453:epidemiology / Q000401:mortality*; D008297:Male; D017063:Outcome Assessment, Health Care; D011237:Predictive Value of Tests; D015995:Prevalence
cerebral hemorrhage; hyponatremia