The stimulation of vascular smooth muscle oxidative metabolism by CSF fromsubarachnoid haemorrhage patients increases with fisher and WFNS grades

The purpose of this paper is to present an in vitro method for examining ce rebral vasospasm after subarachnoid haemorrhage (SAH) which correlates to t he patients' condition. The Oz consumption of the porcine carotid artery wa s monitored, using an oxygen electrode, after exposure to cerebrospinal flu id (CSF) from patients who had a SAH. The vessels were exposed to CSF from SAH patients at a 1 in 30 dilution. Force measurements were carried out usi ng freeze-dried CSF, reconstituted in the organ bath equivalent to undilute d CSP. These observations were then compared to the patients' condition. We divided the patient CSF samples into those that stimulated oxygen consum ption above 0.4 muM/min/g dry wt, and those that did not. It was found that there was a correlation between the stimulation of oxygen consumption and the Fisher grade as well as the World Federation of Neurosurgeons Grading S ystem (WFNS) for the patients. Of the CSF tested. 24 stimulated oxygen cons umption above our cut off, and 8 did not (0.84 +/- 0.34, n = 24 compared wi th the rate of 0.27 +/- 0.1 mu mol/min/g dry wt, respectively; SD n = 8) at 180 minutes. We then examined the Fisher Grades of these two groups, the r esults were 3.21 +/- 0.88 vs 2.25 +/- 0.83 respectively (SD p less than or equal to 0.01). When examining the WFNS System we found a similar differenc e between the groups that stimulated respiration and those who did not (WFN S Grades of 2.64 +/- 1.1 vs. 1.43 +/- 0.53; p less than or equal to 0.01). The observed stimulation of oxygen consumption also correlated with tension generation in vitro. The CSF from subarachnoid haemorrhage patients stimulates the oxygen consum ption of the porcine carotid artery. This stimulation correlated to the WFN S and Fisher Grades of the patients and can be performed using 1:30 dilutio n of CSF. We conclude that the metabolic changes that occur in the vessels during vasospasm are important parameters for assessing cerebral vasospasm.