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Sympathoneuronal and sympathoadrenal activation during ketamine anesthesia
European Journal of Clinical Pharmacology
|September 1, 1979
Summary
Ketamine anesthesia significantly boosts heart rate and blood pressure by increasing noradrenaline and adrenaline levels. Dopamine-beta-hydroxylase (DBH) activity in plasma did not reliably reflect this enhanced sympathetic nervous system activity.
Area of Science:
- Anesthesiology
- Cardiovascular Pharmacology
- Neuropharmacology
Background:
- Ketamine is a widely used anesthetic agent known for its cardiovascular stimulant effects.
- The precise mechanisms underlying ketamine's cardiovascular effects, particularly concerning sympathetic nervous system activation, require further elucidation.
- Investigating plasma catecholamine levels and enzyme activity can provide insights into sympatho-adrenal responses during anesthesia.
Purpose of the Study:
- To investigate the impact of ketamine anesthesia on cardiovascular parameters.
- To quantify changes in plasma noradrenaline, adrenaline, and dopamine-beta-hydroxylase (DBH) activity following ketamine administration.
- To determine the relationship between ketamine-induced cardiovascular stimulation and sympatho-adrenal activity.
Main Methods:
- A study involving 12 patients undergoing ketamine anesthesia (3 mg/kg i.v.).
- Monitoring of cardiovascular parameters including heart rate and blood pressure at specific intervals post-induction.
- Measurement of plasma concentrations of noradrenaline, adrenaline, and DBH activity.
Main Results:
- A significant increase in heart rate (+28%) and blood pressure (systolic +28%, diastolic +17%) was observed within 10 minutes of ketamine induction.
- Concomitant significant elevations in plasma noradrenaline (from 187 to 415 ng/l) and adrenaline (from 97 to 271 ng/l) were noted.
- Plasma DBH activity remained largely unchanged throughout the observation period.
Conclusions:
- The cardiovascular stimulant effects of ketamine are attributed to enhanced sympatho-neuronal and sympatho-adrenal activity, likely mediated by a central mechanism.
- Plasma DBH activity may not serve as a reliable indicator of sympathetic nervous system activity in humans during ketamine anesthesia.
- These findings contribute to understanding the neuropharmacological basis of ketamine's anesthetic and cardiovascular actions.