Hyperacute measurement of brain-tissue oxygen, carbon dioxide, pH, and intracranial pressure before, during, and after cerebral angiography in patients with aneurysmatic subarachnoid hemorrhage in poor condition

Background: The objective of this study was to examine early changes of intracranial pressure (ICP) and brain oxygenation before, during, and after cerebral angiography in patients with poor-grade subarachnoid hemorrhage (SAH). Methods: Fourteen patients with poor-grade SAH without intracerebral hematoma were studied. A significant change in monitored variables (arterial gases, ICP, brain-tissue oxygen pressure [PtiO(2)], brain-tissue carbon dioxide pressure, and pH) was defined as a register deviation of more than 20% compared with the baseline. Critical PtiO(2) values (< 15 mm Hg) or significant PtiO(2) decreases were considered to be impaired brain oxygenation. These data were correlated with the angiography findings and the presence of massive brain edema and hypodense areas in follow-up computed tomography (CT) scan controls. Results: Neurotrend data were unavailable in 4 patients because of calibration failure. Impaired brain oxygenation during angiography was observed in 5 patients. Initial critical PtiO(2) values were found in 1 patient. Four patients developed a linear PtiO(2) and pH decrease after the angio-catheter canalized the examined vessels in the neck. Statistically significant correlation was found between brain pH and PtiO(2) changes in these patients (P < .001, Spearman p). Arterial gases, ICP, and cerebral perfusion pressure did not show significant alterations at this time. Significant correlations existed between severe intracranial angiographic arterial caliber reduction and impaired PtiO(2) values (P < .01). Patients with impaired PtiO(2) values frequently showed lesions in CT scan controls (P < .05). Conclusions: This study documented several fluctuations in the brain oxygenation of patients with poor-grade SAH during angiography. Patients with severe intracranial angiographic arterial caliber reduction at this time have an increased risk for impaired brain oxygenation. (c) 2005 Elsevier Inc. All rights reserved.