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Abstract Background  Patients with aneurysmal subarachnoid hemorrhage (SAH) are at risk for circulatory volume depletion, which is a risk factor for delayed cerebral ischemia (DCI). In a prospective observational study we assessed the effectiveness of fluid administration based on regular evaluation of the fluid balance in maintaining normovolemia. Methods  A total of 50 patients with aneurysmal SAH were included and were treated according to a standard protocol aimed at maintaining normovolemia. Fluid intake was adjusted on the basis of the fluid balance, which was calculated at 6-h intervals. Circulating blood volume (CBV) was measured by means of pulse dye densitometry (PDD) on alternating days during the first 2 weeks after SAH. Results  Of the 265 CBV measurements, 138 (52%) were in the normovolemic range of 60–80 ml/kg; 76 (29%) indicated hypovolemia with CBV  80 ml/kg. There was no association between CBV and daily fluid balance (regression coefficient β = −0.32; 95% CI: −1.81 to 1.17) or between CBV and a cumulative fluid balance, adjusted for insensible loss through perspiration and respiration (β = 0.20; 95% CI: −0.31 to 0.72). Conclusion  Calculations of fluid balance do not provide adequate information on actual CBV after SAH, as measured by PDD. This raises doubt whether fluid management guided by fluid balances is effective in maintaining normovolemia. [ABSTRACT FROM AUTHOR]

Abstract Objective  Magnesium treatment in patients with subarachnoid hemorrhage (SAH) can result in hypocalcemia; this hypocalcemia increases the risk of delayed cerebral ischemia (DCI) and poor outcome. We assessed whether low serum levels of total calcium in patients with SAH treated with magnesium is mediated by parathyroid hormone (PTH) or calcitriol, and whether increased PTH or low serum levels of ionized calcium are associated with an increased risk of DCI and poor outcome. Patients and Methods  We studied 167 patients included in a randomized, placebo controlled trial on magnesium in SAH. Mean serum magnesium during treatment was related to mean serum levels of ionized calcium, PTH and calcitriol with linear regression. Hypocalcemia (Ca2+) and high serum PTH were related to the occurrence of DCI by means of the Cox proportional hazards model and to poor outcome by logistic regression. Results  Serum magnesium was inversely related to ionized calcium (B = −0.1; 95% CI −0.12 to −0.06), but not to PTH or calcitriol. Neither hypocalcemia nor high serum PTH was related to DCI. Hypocalcemia did not increased the risk for poor outcome (OR 1.2; 95% CI 0.6–2.3). In the subgroup of patients with known PTH (n = 67), high serum PTH increased the risk for poor outcome (OR 5.4; 1.6–18.9). Conclusions  Magnesium treatment in patients with SAH leads to hypocalcemia without effect on outcome. PTH is related to poor outcome, but this is independent of magnesium therapy. [ABSTRACT FROM AUTHOR]