Pituitary hormone level changes and hyponatremia in aneurysmal subarachnoid hemorrhage

The aim of this study was to investigate the changes in serum pituitary hormone levels and the mechanism of hyponatremia in aneurysmal subarachnoid hemorrhage (SAH). Nuclear medical tests and serum electrolyte monitoring were performed in 49 aneurysmal SAH cases and 10 healthy volunteers. The levels of serum pituitary hormones were significantly higher in the SAH patients compared with the control group on days 1-3 and 7-9 after SAH onset (P<0.05). The peak value occurred on days 7-9. The rate of hyponatremia was 49.0% in the 49 SAH patients. The incidence of severe hyponatremia was significantly higher in Fisher grades III-IV and Hunt-Hess grades III-IV compared with Fisher grades I-II and Hunt-Hess grades I-II, respectively (P<0.05). There was no correlation between the site of aneurysm and the rate of hyponatremia. The incidence of symptomatic cerebral vasospasm was significantly higher in the hyponatremia group and Fisher grades III-IV compared with the normal serum sodium group and Fisher grades I-II, respectively. Serum pituitary hormone levels were positively correlated with blood loss and disease severity in patients with aneurysmal SAH. Hyponatremia may be considered an important indicator of SAH. SAH patients are likely to benefit from intense monitoring and regulation of serum sodium.