Ming-Yuan Tseng, Pippa G. Al-Rawi, Marek Czosnyka, Peter J. Hutchinson, Hugh Richards, John D. Pickard and Peter J. Kirkpatrick
Systemic administration of 23.5% hypertonic saline enhances cerebral blood flow (CBF) in patients with poor-grade spontaneous subarachnoid hemorrhage (SAH). Whether the increment of change in CBF correlates with changes in autoregulation of CBF or outcome at discharge remains unknown.
Thirty-five patients with poor-grade spontaneous SAH received 2 ml/kg 23.5% hypertonic saline intravenously, and they underwent bedside transcranial Doppler (TCD) ultrasonography and intracranial pressure (ICP) monitoring. Seventeen of them underwent Xe-enhanced computed tomography (CT) scanning for measuring CBF. Outcome was assessed using the modified Rankin Scale (mRS) at discharge from the hospital. The data were analyzed using repeated-measurement analysis of variance and Dunnett correction. A comparison was made between patients with favorable and unfavorable outcomes using multivariate logistic regression.
The authors observed a maximum increase in blood pressure by 10.3% (p <0.05) and cerebral perfusion pressure (CPP) by 21.2% (p <0.01) at 30 minutes, followed by a maximum decrease in ICP by 93.1% (p <0.01) at 60 minutes. Changes in ICP and CPP persisted for longer than 180 and 90 minutes, respectively. The results of TCD ultrasonography showed that the baseline autoregulation was impaired on the ipsilateral side of ruptured aneurysm, and increments in flow velocities were higher and lasted longer on the contralateral side (48.75% compared with 31.96% [p = 0.045] and 180 minutes compared with 90 minutes [p <0.05], respectively). The autoregulation was briefly impaired on the contralateral side during the infusion. A dose-dependent effect of CBF increments on favorable outcome was seen on Xe-CT scans (mRS Score 1–3, odds ratio 1.27 per 1 ml/100 g tissue × min, p = 0.045).
Bolus systemic hypertonic saline therapy may be used for reversal of cerebral ischemia to normal perfusion in patients with poor-grade SAH.
Ming-Yuan Tseng, Peter J. Hutchinson, Carole L. Turner, Marek Czosnyka, Hugh Richards, John D. Pickard and Peter J. Kirkpatrick
The authors previously demonstrated that acute pravastatin therapy in patients after aneurysmal subarachnoid hemorrhage (SAH) ameliorates vasospasm-related delayed ischemic neurological deficits. The object of this study was to continue to examine potential mechanisms of these beneficial effects.
Eighty patients with aneurysmal SAH (age range 18–84 years; time to onset 1.8 ± 1.3 days) were enrolled in a double-blind study and randomized to receive 40 mg of oral pravastatin or placebo daily for as long as 14 days. Daily transcranial Doppler ultrasonography and blood tests every 3 days (including full blood cell counts, coagulation profiles, fasting glucose and lipid profiles, and serum biochemistry) were performed during the trial period.
No significant differences were found in baseline laboratory data between the trial groups. Subsequent measurements during the 14-day trial showed reduced low-density lipoprotein (LDL) cholesterol levels and total/high-density lipoprotein cholesterol ratios between Days 3 and 15 (p < 0.05), and increased D-dimer levels (p < 0.05) on Day 6, in the pravastatin group. Patients who received pravastatin but developed vasospasm had significantly lower baseline LDL cholesterol levels or a less extensive reduction in LDL cholesterol levels (p < 0.05), and greater increases in plasma fibrinogen (p = 0.009) and serum C-reactive protein on Day 3 (p = 0.007), compared with those patients without vasospasm. The reduction in LDL cholesterol levels on Day 3 in the placebo group correlated with the duration of normal cerebral autoregulation on the ipsilateral side of the ruptured aneurysm (p = 0.002).
In addition to functioning through a cholesterol-independent pathway, cerebrovascular protection from acute statin therapy following aneurysmal SAH may also function through cholesterol-dependent mechanisms.
Mauro Bergui and Gianni Boris Bradac