Hyponatremia after aneurysmal subarachnoid hemorrhage: Implications and outcomes

BACKGROUND: Hyponatremia is the most common electrolyte abnormality seen in patients with aneurysmal SAH. Clinically significant hyponatremia (Serum Sodium <131 mEq/L) which needs treatment, has been redefined recently and there is a paucity of outcome studies based on this. This study aims to identify the mean Serum Sodium (S.Na+) level and its duration among inpatients with SAH and to identify the relationship between hyponatremia and the outcome status of patients undergoing surgery for SAH. MATERIALS AND METHODS: This outcome study is undertaken in the department of neurosurgery, The Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala. Medical records of all patients with SAH from 1(st) January to 31(st) July 2010 were reviewed. Preoperative status was assessed using World Federation of Neurosurgical Societies (WFNS) grading system. Discharge status was calculated using the Glasgow outcome score scale. RESULTS: Fifty nine patients were included in the study and 53 (89.8%) of them have undergone surgical treatment. Hyponatremia was observed in 22 of 59 patients (37%). The mean Sodium level of hyponatremic patients was 126.97 mEq/L for a median duration of two days. Glasgow outcome score was good in 89.8% of patients. We lost two patients, one of whom had hyponatremia and vasospasm. CONCLUSION: Hyponatremia is significantly associated with poor outcome in patients with SAH. Anticipate hyponatremia in patients with aneurysmal subarachnoid hemorrhage, timely detect and appropriately treat it to improve outcome. It is more common in patients who are more than 50 years old and whose aneurysm is in the anterior communicating artery. Our comprehensive monitoring ensured early detection and efficient surgical and nursing management reduced morbidity and mortality.