A diagnostic flowchart, including TCD, Xe-CT and angiography, to improve the diagnosis of vasospasm critically affecting cerebral blood flow in patients with subarachnoid haemorrhage, sedated and ventilated

The aim of this study was to prospectively evaluate a clinical protocol including transcranial doppler(TCD), Xenon-CT (Xe-CT) and angiography, for the detection of vasospasmleading to critical reductions of regional cerebral blood flow (rCBF) in both ventilated and sedated SAH patients, i.e. patients in whom clinical evaluation was not possible. Seventy-six patients were prospectively included in a surveillance protocol for daily TCD vasospasmmonitoring. When TCD showed a Vmean above 120 cm/sec in the middle cerebral artery (MCA), patients underwent Xe-CT study. If rCBF in the MCA was reduced to below 20 ml/100 g/min or if there was a reduction in the rCBF with significant asymmetry between the two MCAs, angiographywas performed. Conversely, further Xe-CT and angiographywere not obtained unless the TCD Vmean values reached values above 160 cm/sec. In 35 patients, Vmean attained values above 120 cm/sec, but only in five of them, rCBF was suggestive of vasospasm, and angiographyconfirmed the diagnosis in four.