| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Canadian Journal of Anesthesia, Vol 45, 1084-1090, Copyright © 1998 by Canadian Anesthesiologists' Society
ARTICLES |
Y Watanabe, H Iida, K Tanabe, H Ohata and S Dohi
Department of Anesthesiology and Critical Care Medicine, Gifu University School of Medicine, Japan.
PURPOSE: To evaluate the effects of clonidine on responses to adrenoceptor agonists and baroreflex sensitivity, we examined arterial blood pressure (AP) responses to phenylephrine and heart rate (HR) responses to isoproterenol and baroreflex sensitivity (HR response to AP changes due to phenylephrine or nitroglycerin). METHODS: We studied 60 anaesthetized patients who either did or did not receive 5 micrograms.kg-1 clonidine po before they were anaesthetized. After induction of general anaesthesia, the patients received 3 micrograms.kg-1 phenylephrine, 0.02 microgram.kg-1 isoproterenol, or 2-3 micrograms.kg-1 nitroglycerin, and haemodynamic measurements were taken. Baroreflex sensitivity was expressed as the slope of the linear regression line (msec.mmHg-1; in msec of R-R interval change vs mmHg change in systolic arterial pressure) following the administration of phenylephrine and nitroglycerin. RESULTS: Patients who received clonidine had greater augmented responses in AP to phenylephrine and in HR to isoproterenol (47.2 +/- 15.6% vs 23.7 +/- 11.9% for increase in systolic AP and 59.8 +/- 22.6% vs 26.2 +/- 11.0% for increase in HR, P < 0.05 respectively). There were no differences between the baroreflex sensitivities in the pressor (phenylephrine) test groups (3.77 +/- 1.08 vs 4.41 +/- 1.66 msec.mmHg-1). In contrast, the slopes of depressor (nitroglycerin) test groups were decreased in patients receiving clonidine (1.98 +/- 0.73 vs 3.68 +/- 1.72 msec.mmHg-1, P < 0.05). CONCLUSION: The results suggest that premedication with clonidine might enhance critical hypotension during anaesthesia and surgery, but restoration both of AP and HR decrease can be achieved effectively by phenylephrine and isoproterenol i.v., respectively.
This article has been cited by other articles:
![]() |
L. A. Campos, R. Iliescu, M. A. P. Fontes, W.-P. Schlegel, M. Bader, and O. C. Baltatu Enhanced isoproterenol-induced cardiac hypertrophy in transgenic rats with low brain angiotensinogen Am J Physiol Heart Circ Physiol, November 1, 2006; 291(5): H2371 - H2376. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Ikeda, K. Nishikawa, K. Ohashi, T. Mori, and A. Asada Epidural Clonidine Suppresses the Baroreceptor-Sympathetic Response Depending on Isoflurane Concentrations in Cats Anesth. Analg., September 1, 2003; 97(3): 748 - 754. [Abstract] [Full Text] [PDF] |
||||
![]() |
D.-Z. Hsu, P.-J. Chiang, C.-H. Hsu, B.-M. Huang, J.-F. Deng, and M.-Y. Liu The elucidation of epinephrine as an antihypotensive agent in abamectin intoxication Human and Experimental Toxicology, August 1, 2003; 22(8): 433 - 437. [Abstract] [PDF] |
||||
![]() |
M. Licker, G. Khatchatourian, A. Schweizer, M. Bednarkiewicz, D. Tassaux, and C. Chevalley The Impact of a Cardioprotective Protocol on the Incidence of Cardiac Complications After Aortic Abdominal Surgery Anesth. Analg., December 1, 2002; 95(6): 1525 - 1533. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Ohata, H. Iida, Y. Watanabe, and S. Dohi Hemodynamic Responses Induced by Dopamine and Dobutamine in Anesthetized Patients Premedicated with Clonidine Anesth. Analg., October 1, 1999; 89(4): 843 - 843. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Hayakawa-Fujii, H. Iida, and S. Dohi Propofol Anesthesia Enhances Pressor Response to Ephedrine in Patients Given Clonidine Anesth. Analg., July 1, 1999; 89(1): 37 - 37. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |