Arachidonic acid metabolism following aneurysm rupture evaluation of cerebrospinal fluid and serum concentration of 6-keto-prostaglandin F 1α and thromboxane B 2 in patients with subarachnoid hemorrhage

Abstract

Experimental investigations have suggested an important role of arachidonic acid metabolites in the genesis of cerebral vasospasm following subarachnoid hemorrhage. In this clinical study the cerebrospinal fluid (CSF) and serum levels of the two main arachidonic acid metabolites prostacyclin and thromboxane A 2 are evaluated by measuring their stable degradation products 6-keto-prostaglandin F 1α (6-keto-PGF 1α) and thromboxane B 2 (TXB 2) using radioimmunoassay methods during the pre- and postoperative course in patients after aneurysm rupture. Although the serum levels of both substances do not seem to be important for the clinical course of the patients, the CSF concentrations of 6-keto-PGF 1α and TXB 2 provide important data. A close correlation between the initial TXB 2 level of the individual patient and the amount of blood in the basal cisterns as detected by computed tomography scan can be demonstrated. The predictive value of this additional information for the occurrence of cerebral angiospasm is discussed. Comparing the CSF levels of both metabolites the slight preoperative elevation of 6-keto-PGF 1α is significantly surmounted by an extraordinary rise in TXB 2 concentration. Postoperatively, after cleavage of the basal cisterns there is a decline in the CSF levels of both substances. The pre- and postoperative clinical course in comparison to the CSF levels of 6-keto-PGF 1α and TXB 2 is demonstrated in four patients. A nearly normal course of TXB 2 and 6-keto-PGF 1α seems to be associated with an uneventful clinical course, whereas a high TXB 2 level—whether occurring preoperatively or, even more important, as a secondary postoperative rise—seems to be associated with ischemic complications and neurological deterioration. It is suggested that pre- and post- operative monitoring of CSF levels of 6-keto-PGF 1α and especially TXB 2 may serve as a possible indicator for the detection of patients at risk of developing cerebral vasospasm.