Effects of hyperoxia, glycerol and ventricular drainage on ICP and CBF in patients with increased ICP due to CSF circulatory-absorbance disturbance

The effects of hyperoxia, glycerol and ventricular drainage on intracranial pressure (ICP) and cerebral blood flow (CBF) were studied in cases with cerebrospinal fluid (CSF) circulatory-absorbance disturbance due to subarachnoid hemorrhage (SAH) or intraventricular hematoma. Ventricular fluid pressure (VFP) was monitored through a controlled ventricular drainage (CVD) tube using a Statham P-50 pressure transducer. CBF was measured by the 10mCi133Xe intravenous injection method using a Valmet BI-1400 rCBF analyzer. ISI (initial slope index) was used for the CBF value. Studied cases were 19 SAH patients and 2 hypertensive intracerebral hematoma cases with intraventricular hematoma. Hyperoxia included hyperbaric oxygen (HBO), reduced ICP and CBF. During pure oxygen inhalation at atmospheric pressure (1ATA . O2), there was a tendency toward a relationship showing that the higher the resting state ICP, the lesser the likelihood of a CBF decrease. This may indicate that increased ICP impairs cerebral vascular reactivity to hyperoxia in relation to the degree of elevation. The effects of hyperoxia on ICP and CBF were temporary and they promptly returned to the resting state after cessation of oxygen inhalation. In some cases, there was a rebound phenomenon in ICP after HBO. Glycerol administration reduced ICP and increased CBF. There was no clear correlation between resting state ICP and CBF increase after glycerol administration. The effects of glycerol were also temporary. ICP control by opening CVD increased CBF. There was a correlation between the level of resting state ICP and the CBF increase after the opening of CVD. In cases with CSF circulatory-absorbance disturbance, elevated ICP reduced CBF and may further worsen the cerebral damage.(ABSTRACT TRUNCATED AT 250 WORDS)