English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The cerebral and systemic kinetics of intravenous thiopentone (250 mg over 2 minutes, n=5) and propofol (100 mg over 2 minutes, n=6) were determined in sheep anaesthetized with halothane (2.0%) and mechanically ventilated to an end-expired carbon dioxide tension of 40 mmHg. The sheep were previously instrumented with arterial and sagittal sinus (effluent from the brain) blood sampling catheters. Systemic kinetics were inferred from the time-course of the arterial blood concentrations, and cerebral kinetics from the time-course of the arterio-sagittal sinus concentration difference across the brain. Under halothane anaesthesia, the peak arterial concentrations of each drug occurred at the end of the two-minute infusion, and was 42.3 mg/l and 12.3 mg/l for thiopentone and propofol, respectively. Propofol had a significantly larger systemic clearance (3.19 l/min) than thiopentone (0.99 l/min). The brain concentrations of propofol equilibrated more slowly with the arterial concentrations than those of thiopentone. The extraction ratio across the brain near the end of the infusions (1.5 min) were 0.85 and 0.46 respectively. These data were also compared to analogous previously published data for initially conscious sheep. The systemic kinetics of thiopentone were little affected by halothane anaesthesia. For propofol, halothane anaesthesia was associated with a statistically significant reduction in clearance (50% of awake), a slower initial half-life (247% of awake), and the emergence of a second slower half-life in some sheep. The cerebral kinetics of both drugs were subtly altered by halothane anaesthesia.

The Cerebral and Systemic Kinetics of Thiopentone and Propofol in Halothane Anaesthetized Sheep