Hypomagnesemia after aneurysmal subarachnoid hemorrhage.
OBJECTIVE
Hypomagnesemia frequently occurs in hospitalized patients, and it is associated with poor outcome. We assessed the frequency and time distribution of hypomagnesemia after aneurysmal subarachnoid hemorrhage (SAH) and its relationship to the severity of SAH, delayed cerebral ischemia (DCI), and outcome after 3 months.


METHODS
Serum magnesium was measured in 107 consecutive patients admitted within 48 hours after SAH. Hypomagnesemia (serum magnesium <0.70 mmol/L) at admission was related to clinical and initial computed tomographic characteristics by means of the Mann-Whitney U test. Hypomagnesemia at admission and during the DCI onset period (Days 2-12) was related to the occurrence of DCI and hypomagnesemia at admission, and hypomagnesemia that occurred any time during the first 3 weeks after SAH was related to outcome.


RESULTS
Hypomagnesemia at admission was found in 41 patients (38%) and was associated with more cisternal (P = 0.006) and ventricular (P = 0.005) blood, a longer duration of unconsciousness (P = 0.007), and a worse World Federation of Neurosurgical Societies scale score at admission (P = 0.001). The crude hazard ratio for DCI with hypomagnesemia at admission was 2.4 (95% confidence interval, 1.0-5.6), and after multivariate adjustment it was 1.9 (95% confidence interval, 0.7-4.7). The hazard ratio of hypomagnesemia from Days 2 to 12 for patients with DCI was 3.2 (range, 1.1-8.9) after multivariate adjustment. The crude odds ratio for poor outcome (Glasgow Outcome Scale score, 1-3) with hypomagnesemia at admission was 2.5 (range, 1.1-5.5). Hypomagnesemia at admission did not contribute to the prediction of outcome in the multivariate model.


CONCLUSIONS
Hypomagnesemia is frequently present after SAH and is associated with severity of SAH. Hypomagnesemia occurring between Days 2 and 12 after SAH predicts DCI.
van den Bergh
Walter M
WM
Department of Neurosurgery, University Medical Center Utrecht, Utrecht, The Netherlands. w.m.vandenbergh@neuro.azu.nl
Algra
Ale
A
van der Sprenkel
Jan Willem Berkelbach
JW
Tulleken
Cornelis A F
CA
Rinkel
Gabriël J E
GJ
D000368:Aged; D017542:Aneurysm, Ruptured / Q000175:diagnosis* / Q000401:mortality; D002545:Brain Ischemia / Q000175:diagnosis* / Q000401:mortality; D014695:Cerebral Ventriculography; D005260:Female; D005500:Follow-Up Studies; D023261:Glasgow Outcome Scale; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis* / Q000401:mortality; D008274:Magnesium / Q000097:blood; D008275:Magnesium Deficiency / Q000175:diagnosis* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009460:Neurologic Examination; D011379:Prognosis; D011446:Prospective Studies; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis* / Q000401:mortality; D015996:Survival Rate; D014057:Tomography, X-Ray Computed
D008274:Magnesium