Sympathetic and hemodynamic effects of moderate and deep sedation with propofol in humans. Anesthesiology 2005 Jul;103(1):20-4
Date
06/29/2005Pubmed ID
15983452DOI
10.1097/00000542-200507000-00007Scopus ID
2-s2.0-21744448216 (requires institutional sign-in at Scopus site) 112 CitationsAbstract
BACKGROUND: The objective of this study was to determine the mechanisms involved in the hypotension associated with sedative doses of propofol in humans.
METHODS: Ten healthy volunteers (aged 21-37 yr) participated on two occasions and in random order received placebo or propofol infusions. Standard monitoring and radial artery blood pressure were combined with measurement of forearm blood flow (plethysmography) and derivation of forearm vascular resistance, recording of peroneal nerve sympathetic activity, and blood sampling for norepinephrine concentrations. A computer-controlled infusion pump delivered placebo or two concentrations of propofol, adjusted to achieve moderate and deep sedation based on the Observer Assessment of Alertness/Sedation score (responsiveness component) of 4 and 3. Level of sedation was quantitated using bispectral analysis of the electroencephalogram. Baroreflexes were assessed with a hypotensive challenge via administration of sodium nitroprusside.
RESULTS: Baseline neurocirculatory and respiratory parameters did not differ between sessions. Progressive infusions to achieve moderate and deep sedation resulted in average Bispectral Index values of 70 and 54, respectively. Propofol significantly reduced sympathetic nerve activity at both levels of sedation and decreased norepinephrine and forearm vascular resistance at deep sedation. These effects resulted in significant decreases in mean blood pressure of 9% and 18% at moderate and deep sedation, respectively. Propofol also reduced reflex increases in sympathetic nerve activity.
CONCLUSIONS: These data from healthy subjects indicate that sedation doses of propofol, which did not compromise respiratory function, had substantial inhibitory effects on sympathetic nerve activity and reflex responses to hypotension resulting in vasodilation and significant decreases in mean blood pressure.
Author List
Ebert TJAuthor
Thomas J. Ebert MD, PhD Adjunct Professor in the Anesthesiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Adrenergic FibersAdult
Baroreflex
Blood Pressure
Female
Heart Rate
Hemodynamics
Humans
Hypnotics and Sedatives
Linear Models
Male
Propofol
Sympatholytics
