Document Detail


The effect of infusions of adrenaline, noradrenaline and dopamine on cerebral autoregulation under propofol anaesthesia in an ovine model.
MedLine Citation:
PMID:  12595982     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: To compare the effects of infusions of adrenaline, noradrenaline and dopamine on cerebral autoregulation under steady-state propofol anaesthesia with the awake state. DESIGN: Prospective, randomised, interventional animal study. SETTING: University laboratory. SUBJECTS: Six studies in two cohorts of adult ewes: awake and steady-state propofol anaesthesia (15 mg/min). INTERVENTIONS: In random order, each animal received ramped infusions of adrenaline, noradrenaline (0-40 microg/min) and dopamine (0-40 microg/kg per min). MEASUREMENTS AND RESULTS: Cerebral blood flow (CBF) was measured continuously from changes in Doppler velocities in the sagittal sinus and normalised to a PaCO(2) 35 mmHg. Propofol decreased CBF by 55% relative to pre-anaesthesia values (p=0.0001). All three catecholamines significantly and equivalently increased mean arterial pressure (MAP) from baseline in a dose-dependent manner in both awake and propofol cohorts. Adrenaline significantly increased CBF from baseline in both awake sheep (p<0.01) and during propofol anaesthesia (p<0.001); noradrenaline and dopamine did not statistically increase CBF. When comparing the effects of individual catecholamines with each other within each cohort, no statistically significant difference between the catecholamines was demonstrated. (p>0.05). Using linear regression analysis, normalised CBF was correlated against associated changes in MAP. No significant differences were demonstrated between the slopes of regression lines for adrenaline, noradrenaline and dopamine in either cohort (ANCOVA). There was a statistically significant difference between the intercepts of the awake and propofol cohorts (p<0.0001), but no difference between the slopes (p=0.69). CONCLUSIONS: Over a specific dose range, catecholamine-induced hypertension caused increased CBF during steady-state propofol anaesthesia. This effect was offset by an associated reduction in CBF caused by propofol. The concomitant administration of propofol and catecholamines was not associated with altered autoregulatory function compared to the awake state.
Authors:
John A Myburgh; Richard N Upton; Cliff Grant; Allison Martinez
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2003-02-21
Journal Detail:
Title:  Intensive care medicine     Volume:  29     ISSN:  0342-4642     ISO Abbreviation:  Intensive Care Med     Publication Date:  2003 May 
Date Detail:
Created Date:  2003-05-15     Completed Date:  2003-09-23     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7704851     Medline TA:  Intensive Care Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  817-24     Citation Subset:  IM    
Affiliation:
Department of Anaesthesia and Intensive Care, University of Adelaide and Royal Adelaide Hospital, 5000 Adelaide, Australia. j.myburgh@unsw.edu.au
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MeSH Terms
Descriptor/Qualifier:
Anesthesia, Intravenous*
Anesthetics, Intravenous*
Animals
Blood Pressure / drug effects
Brain / drug effects*,  metabolism
Dopamine / administration & dosage,  pharmacology*
Epinephrine / administration & dosage,  pharmacology*
Female
Homeostasis / drug effects*
Norepinephrine / administration & dosage,  pharmacology*
Propofol*
Sheep
Chemical
Reg. No./Substance:
0/Anesthetics, Intravenous; 2078-54-8/Propofol; 51-41-2/Norepinephrine; 51-43-4/Epinephrine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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