• Y Kurokawa, T Uede, M Ishiguro, O Honda, O Honmou, T Kato, and M Wanibuchi.
• Department of Neurosurgery, Kushiro City General Hospital, Japan.
• Surg Neurol. 1996 Nov 1; 46 (5): 500-7; discussion 507-8.

BackgroundHyponatremia following subarachnoid hemorrhage (SAH) occurs due to the inappropriate secretion of antidiuretic hormone (SIADH). However, this condition is also sometimes associated with certain dehydration states.MethodsTo clarify the pathogenesis, daily values of urine volume, water balance, and sodium balance (Na Bal) were correlated with plasma levels of atrial natriuretic peptide (ANP), antidiuretic hormone (ADH), and plasma renin activity (PRA) in 31 cases of SAH.ResultsNa Bal was markedly negative on days 2 and 3. Cumulative Na Bal showed continuous negative values until day 10 following SAH. ANP values showed a consistent elevation, while ADH showed only an initial surge. PRA, as the gross indicator of circulatory volume, showed a lack of suppression, indicating no increase in the circulatory volume.ConclusionHyponatremia following SAH therefore appears to be the result of increased natriuresis, due to the inappropriate elevation of ANP rather than SIADH. In this situation, water restriction should not be recommended, since the circulatory volume is decreased.

30 keywords...

hide…