Effects of subarachnoid hemorrhage on cerebral blood volume, blood flow, and oxygen utilization in humans

Abstract

Forty-five studies of regional cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), and regional cerebral oxygen utilization (rCMRO2) were performed in 30 patients undergoing diagnostic cerebral angiography for evaluation of a subarachnoid hemorrhage due to a ruptured intracranial aneurysm. Tracer methods employing radioactive oxygen-15 were used to measure rCBV, rCBF, and rCMRO2. The patient studies were divided into groups based on their neurological status and the presence or absence of cerebral vasospasm. Subarachnoid hemorrhage, with and without vasospasm, produced significant decreases in CBF and CMRO2. In general, patients with more severe neurological deficits, and patients with more severe degrees of vasospasm, had a more marked depression of CBF and CMRO2. The most striking finding was a significant (p less than 0.001) increase in CBV (to 58% above normal) in patients with severe neurological deficits associated with severe cerebral vasospasm. This large increase suggests that cerebral vasospasm consists of constriction of the large, radiographically visible extraparenchymal vessels accompained by a massive dilation of intraparenchymal vessels.

Global and focal cerebral perfusion after aneurysmal subarachnoid hemorrhage in relation with delayed cerebral ischemia

“…This is enabled by a prolonged MTT since the slow flow of blood results in greater extraction of oxygen. [16] In the present study, patients were scanned on admission in the subacute phase after SAH. Clinically stable patients had initially highest global brain CBF values compared to patients with clinical deterioration and showed an increasing CBV, which represents adequate autoregulation.…”

Carbon dioxide reactivity during prostaglandin E1. induced hypotension for cerebral aneurysm surgery

“…[3][4][5] reported that there was a risk of postoperative neurological deficit in patients with impaired autoregulation. 6 Several intravenous drugs such as trimethaphan (TMP), nitroglycerine (TNG), adenosine and sodium nitroprusside (SNP) have been used to induce hypotension but it is difficult to identify a preferable drug.…”

Time-Course of Cerebral Perfusion and Tissue Oxygenation in the First 6 h after Experimental Subarachnoid Hemorrhage in Rats

“…Voldby et al found a concomitant decrease of CMRO 2 with arterial caliber, indicating secondary metabolic impairment due to cerebral vasospasm (Voldby et al, 1985). Other authors did not observe an additional depression of CMRO 2 with the appearance of delayed vasospasm and advocated a primary reduction of metabolism by SAH (Grubb et al, 1977;Carpenter et al, 1991;Frykholm et al, 2004). All of these studies, however, measured CBF and metabolic parameters in patients at various times after SAH and after hospital admission.…”