What question did this study set out to answer?

To compare the effects of halothane, ketamine, propofol, and alfentanil anesthesia on baroreceptor heart rate control and hemodynamic compensatory responses to acute central hypovolemia.

November 1, 1990Clinical and Experimental Pharmacology and Physiology

Effects of Halothane, Ketamine, Propofol and Alfentanil Anaesthesia on Circulatory Control in Rabbits

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Authors

ALAndrew F. Van LeeuwenThe Royal Melbourne Hospital RERoger G. EvansGeneral Cardiology JLJohn LudbrookSouth Australia Pathology

Discussion

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Implication

Alfentanil preserved compensatory vasoconstriction during hypovolemia unlike other agents; leaves open translation to human anesthetic selection.

Key Points

To compare the effects of halothane, ketamine, propofol, and alfentanil anesthesia on baroreceptor heart rate control and hemodynamic compensatory responses to acute central hypovolemia.
Tested rabbits in a randomized-order crossover design across five protocols: unanesthetized baseline, conscious sham gas exposure, and four anesthetic regimens following thiopentone induction.
Administered halothane (2.0% and 2.5%), ketamine (2.5 mg/kg per min), propofol (0.83 and 1.25 mg/kg per min), or alfentanil (2.5 and 3.33 micrograms/kg per min) during mechanical ventilation.
Simulated acute hemorrhage by inflating an inferior vena caval cuff to drop cardiac output at 8.5%/min and assessed baroreflex ranges using inflatable aortic and vena caval cuffs.
Halothane, ketamine, and propofol significantly attenuated the initial vasoconstrictor compensation phase, leading to a steeper fall in arterial pressure during simulated blood loss.
Alfentanil preserved and extended the vasoconstrictor phase, maintaining normal arterial pressure even after cardiac output fell by 59%, an effect reproduced by intracerebroventricular injection into the fourth ventricle.
Baroreceptor control of heart rate was attenuated by all four anesthetic agents and nitrous oxide, with impairment being most pronounced with halothane and least pronounced with alfentanil and nitrous oxide.

Cite This Study

Leeuwen et al. (1990) studied this question.

synapsesocial.com/papers/6a846b2f22c36ed33af7a04d https://doi.org/10.1111/j.1440-1681.1990.tb01280.x

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Implication

Alfentanil preserved compensatory vasoconstriction during hypovolemia unlike other agents; leaves open translation to human anesthetic selection.

Effects of Halothane, Ketamine, Propofol and Alfentanil Anaesthesia on Circulatory Control in Rabbits

Discussion

Member takes

Implication

Key Points

Cite This Study

Effects of Halothane, Ketamine, Propofol and Alfentanil Anaesthesia on Circulatory Control in Rabbits

Discussion

Member takes

Implication

Key Points

Cite This Study

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