title: High incidence of hyponatremia in patients with ruptured anterior communicating artery aneurysms.
abstract: We studied the incidence and timing of hyponatremia (Na < 135 mEq l-1) after subarachnoid hemorrhage (SAH) with special reference to ruptured anterior communicating artery (A-com) aneurysms. Hunt and Kosnik (HK) grading, symptomatic vasospasm in A-com aneurysm, and hydrocephalus were analyzed for connections to hyponatremia in 55 patients with ruptured A-com aneurysms, 65 with ruptured internal cerebral artery (ICA) aneurysms, and 49 with ruptured middle cerebral artery (MCA) aneurysms. Hyponatremia occurred in 28 (51%) of 55 patients with A-com aneurysms and in nine (18%) of 49 patients with MCA aneurysms. Severe hyponatremia (Na < 130 mEq l-1) occurred in 16 patients (29%) in the A-com group, four patients (6%) in the ICA group, and three patients (6%) in the MCA group. The A-com aneurysm group had a significantly higher incidence of mild hyponatremia (p < 0.01) and severe hyponatremia (p < 0.001) than other groups. Among A-com cases, hyponatremia occurred significantly more often in HK grade III and IV cases (p < 0.05), in cases with vasospasm (p < 0.001), and in cases with hydrocephalus (p < 0.01). Respective days of onset for symptomatic vasospasm and for hyponatremia were day 7.6 +/- 4.4 and day 10.6 +/- 5.8 following SAH, representing a 3-day delay for hyponatremia (p < 0.05). In most patients hyponatremia resolved within 28 days following SAH. Hyponatremia occurred more often with A-com aneurysms, possibly because of vasospasm around the A-com or hydrocephalus causing hypothalamic dysfunction. Since hypervolemic therapy can cause hyponatremia, particularly careful observation is required during such therapy in patients with A-com aneurysm.
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sayama
authors.forename: T
authors.initials: T
authors.lastname: Inamura
authors.forename: T
authors.initials: T
authors.lastname: Matsushima
authors.forename: S
authors.initials: S
authors.lastname: Inoha
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: M
authors.initials: M
authors.lastname: Fukui
mesh_terms: D017542:Aneurysm, Ruptured / Q000150:complications*; D006801:Humans; D006849:Hydrocephalus / Q000150:complications; D007010:Hyponatremia / Q000453:epidemiology* / Q000209:etiology*; D015994:Incidence; D002532:Intracranial Aneurysm / Q000150:complications*; D012189:Retrospective Studies; D013345:Subarachnoid Hemorrhage / Q000209:etiology; D020301:Vasospasm, Intracranial / Q000453:epidemiology / Q000209:etiology