Abstract TP532: Decreased Serum Sodium Levels Predict Symptomatic Vasospasm in Patients With Subarachnoid Hemorrhage

Background: Symptomatic vasospasm (SVS) is one of the major causes of morbidity and mortality in patients with subarachnoid hemorrhage (SAH). Hyponatremia and dehydration due to natriuresis after SAH is related to SVS and predicts it. Therefore, nowadays most institutions target to euvolemia and eunatremia in SAH patients to avoid complications. In this study, we retrospectively investigated the predictors of SVS in terms of water and sodium homeostasisunder maintaining euvolemia and eunatremia after SAH. We also analyzed the relationship between hyponatremia and the effect of treatment modality (clipping and endovascular coiling). Methods: We monitored changes in serum sodium levels, serum osmolarity, daily sodium intake, daily urine volume, and daily water balance during 14 days after SAH. Outcome was assessed using the modified Rankin scale one month after subarachnoid hemorrhage. Results: Among 105 patients, 29 (27.6%) had SVS. Patients with SVS were older than those without SVS and SVS affected outcome. Serum sodium levels were sequentially significantly decreased within normal range from one day before occurrence of SVS.Among the patients, 67 (63.8%) were treated with surgical clipping and 38 (36.2%) were treated with endovascular coiling. The group with coiling suffered significantly more severe hyponatremia and had less urine volume compared with the clipping group. Conclusions: SVS occurs more often in older patients and affects outcome. Serum sodium level decrease occurs one day before SVS. This observation may help predict SVS. A further large prospective study is necessary to resolve the detailed relationships among hyponatremia, urine volume, treatment modality and SVS in patients with SAH.