Characterization of cerebral salt wasting after subarachnoid hemorrhage model induced by endovascular puncture

Cerebral salt wasting (CSW) frequently occurs concomitantly with an aneurysmal subarachnoid hemorrhage (SAH). CSW induces excessive natriuresis and osmotic diuresis, and reduces the total volume of blood. We previously reported that a rat model with SAH induced by endovascular puncture (EP) exhibited CSW. Therefore, we investigated the relationship between the spread of bleeding in the subarachnoid space and the intensity of CSW. We also investigated the development of CSW in different SAH models. SAH was induced by EP or by 0.3 mL of blood injection (BI) into the cisterna magna. To evaluate the occurrence of CSW, urine was cumulatively collected at the onset of SAH to 6 h later and analyzed for sodium (Na) excretion. SAH was classified from grade 1 (no bleeding) to grade 4 (severe bleeding) based on the spread of bleeding in the subarachnoid space. In the EP model (SAH grade > 2) as the SAH grade increased, the volume of urine and Na excretion also significantly increased. Although the BI model rats exhibited SAH of grade 4, the volume of urine and Na excretion did not change. Therefore, our conclusion is that the spread of bleeding in the subarachnoid space may not cause CSW.