Effect of intraventricular haemorrhage and rebleeding following subarachnoid haemorrhage on CSF eicosanoids

CSF eicosanoid levels are raised following subarachnoid haemorrhage but not sufficiently to be vasoactive per se within the cerebral circulation. Rebleeding and intraventricular haemorrhage are two factors associated with a worse outcome after aneurysmal SAH. We have examined the effects of these two factors on the CSF levels of TXB2 (TXA2 metabolite), PG6-keto F1 alpha (prostacyclin metabolite), PGF2 alpha and PGE2 in 44 patients following subarachnoid haemorrhage. In 15 patients who had received no non-steroidal anti-inflammatory agent or dexamethasone, intraventricular haemorrhage increased the median levels of all four eicosanoids in ventricular CSF by 2.1-5.1-fold. In 4 patients who rebled, the CSF median levels of all four eicosanoids were raised up to 250-fold over the normal range. These concentrations are just sufficient to have cerebrovascular and neuromodulatory effects.