Cerebral hemodynamics in patients with acute severe head trauma

Abstract

Mean hemispheric cerebral blood flow (CBF) was studied in 11 comatose brain-injured patients following intravenous administration of xenon-133. Repeated measurements were performed in order to evaluate cerebral vasoreactivity following a decrease in PaCO2. In addition, the effect of induced barbiturate coma was evaluated in patients with intracranial hypertension. The cerebral vasoreactivity and the CBF response following induction of barbiturate coma varied. In patients with normal CO2 reactivity, barbiturate treatment was accompanied by a considerable decrease in CBF as compared to patients with decreased or abolished CO2 response. During barbiturate treatment the intracranial pressure (ICP) became normal in three of four patients with preserved CO2 response, but reached normal levels in only one of five patients with impaired CO2 reactivity. Patients whose ICP became normal recovered. The data suggest a positive correlation between CO2 reactivity and the effect of barbiturate treatment. Furthermore, preserved cerebral vasoreactivity after severe head injury may be of prognostic value.

Induced hypothermia in adult community-acquired bacterial meningitis – more than just a possibility?

“…Current treatments are frequently aimed at reducing intracranial pressure and depend on cerebral vasoreactivity. 18,19 In severe bacterial meningitis, however, cerebral blood flow (CBF) autoregulation is often damaged. Furthermore, cerebral metabolic oxygen demand (CMRO 2 ) and CBF coupling is frequently disrupted and leads to multisegmental hypoperfusion or hyperemia.…”

Prospective observational cohort study of cerebrovascular CO2 reactivity in patients with inflammatory CNS diseases

“…It should be stressed that it is not possible to distinguish these patients by clinical examination or with CT brain scan. The effects of conventional symptomatic treatment (osmotic diuresis, thiopental, hyperventilation) are greatly dependent (or associated with) on cerebral arterioles vasoreactivity [27]. Patients with impaired CO 2 R are candidates for therapeutic hypothermia (TH).…”

Age-related carbon dioxide reactivity in children after moderate and severe traumatic brain injury

“…Additional studies with larger numbers of patients that are designed to evaluate the impact of MOI on CO 2 R and outcome are needed. Multiple studies involving adult patients have shown a link between poor neurological outcomes and impaired CO 2 R. 8,13,[19][20][21]28 One pediatric study found patients with higher mean CO 2 R trended toward a more favorable outcome, and CO 2 R < 2%/torr PaCO 2 in the first 48 hours after injury was correlated with poor neurological outcome at 6 months after injury.…”