Journal of neurology, neurosurgery, and psychiatry
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J. Neurol. Neurosurg. Psychiatr. · Apr 1995
Extracerebral absorption of near infrared light influences the detection of increased cerebral oxygenation monitored by near infrared spectroscopy.
The detection of increased cerebral oxygenation secondary to cerebral hyperaemia, induced by hypercapnia has been studied in anaesthetised patients using a near infrared, reflectance mode, cerebral oxygenation monitor (Invos 3100 Somanetics, Troy, Michigan, USA). Two studies were performed, with and without a pneumatic scalp tourniquet, to distinguish between extracranial and intracranial changes in tissue oxygenation. In the control study a mean increase in end tidal CO2 of 23.1 mm Hg was accompanied by a mean increase in middle cerebral artery flow velocity of 116%. ⋯ There was no correlation between the change in middle cerebral artery flow velocity and rSO2 in the control or scalp ischaemia group. This study shows that the Invos 3100 monitor is sensitive to tissue oxygenation but does not reliably detect changes in cerebral oxygenation as a result of profound cerebral hyperaemia. The contribution of extracerebral tissue to the attenuation of near infrared light and the lack of spatial resolution remain major problems to be overcome before this or other near infrared spectroscopy instruments can be introduced into clinical practice.
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J. Neurol. Neurosurg. Psychiatr. · Apr 1995
Clinical TrialIntraventricular recombinant tissue plasminogen activator for lysis of intraventricular haemorrhage.
A prospective series of 20 patients with moderate to severe intraventricular haemorrhage (IVH) was studied for the effect of intraventricular administration of recombinant tissue plasminogen activator (rt-PA) on reduction of haematoma volume and prognosis. On the day of haemorrhage ventriculostomy was performed and 2 to 5 mg of rt-PA were injected via the external ventricular drainage, followed by drainage closure for two hours. In 14 patients rt-PA treatment was repeated. ⋯ One patient did not survive the IVH. Intraventricular treatment with rt-PA seems effective in rapid lysis of intraventricular haematoma and normalisation of impaired CSF circulation. This treatment may contribute to an improvement in prognosis of moderate to severe IVH.