Introduction & Objective: Electrolyte disturbances are frequently observed during the acute period after spontaneous subarachnoid hemorrhage (SAH). Hyponatremia and hypernatremia are the most common electrolyte disturbance in acute period of disease, and these disturbances may worsen cerebral edema and mass effect. We performed this study to determine the prognostic significance of serum sodium concentration abnormalities.

Materials & Methods: This study was performed as prospective analytic cross sectional in Kashani and Alzahra Hospitals of Isfahan during 2003-2004. The presence of hypernatremia (serum sodium concentration of>145m mol/L) and hyponatremia (serum sodium concentration of<135mmol/l) was determined with serum sodium measurements at admission and 3, 6 and 9 days after SAH, then the effects of hypernatremia and hyponatremia on three-month outcomes were analyzed after adjustment for age, sex, preexiting HTN , admission GCS score, initial mean arterial pressure and finding of Brain CT Scan and Brain angiography. Patients with symptomatic vasospasm were excluded.

Results: The analysis of data showed that from 100 participated patients in this study 18% developed hypernatremia and 42% developed hyponatremria. Hypernatemia was significantly assiociated with poor outcomes compared with hyponatremia (odds ratio, 2.63- CI 95% ).

Conclusion: Hyponatremia seems to be more common than hypernatremia after SAH. Hypernatrenia after SAH associted with poor outcome and this association is independet of previously identified outcome predictors, including age, sex, admission GCS Score, and X.Ray finding.