Antinociceptive effects of epidural magnesium sulphate alone or in combination with morphine in ...

131 Pages·2015·5.95 MB·English

by  Bahrenberg, Anne

ANNE BAHRENBERG
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morphine in dogs

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Inauguraldissertation zur Erlangung des Grades eines
édition scientifique B
VVB LAUFERSWEILER VERLAG E Dr. med. vet.
N
beim Fachbereich Veterinärmedizin der Justus-Liebig-Universität Gießen
VVB LAUFERSWEILER VERLAG N
STAUFENBERGRING 15 ISBN: 978-3-8359-6269-9
A
D-35396 GIESSEN
Tel: [phone] Fax: -5599890
[email protected]
www.doktorverlag.de 9 783835 962699
édition scientifique
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édition scientifique
VVB LAUFERSWEILER VERLAG
STAUFENBERGRING 15, D-35396 GIESSEN
Tel: [phone] Fax: [phone]
email: [email protected]
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Faculty of Veterinary Medicine, Clinic of Small Animal, Surgery
Justus-Liebig-University Giessen, Germany
Prof. Dr. Sabine Tacke
and
Faculty of Veterinary Science, Department of Companion Animal Clinical Studies
University of Pretoria, South Africa
Dr. Eva Rioja-Garcia

Antinociceptive effects of epidural magnesium
sulphate alone or in combination
with morphine in dogs

INAUGURAL DISSERTATION
for the acquisition of the doctoral degree
at the Faculty of Veterinary Medicine
Justus-Liebig-University Giessen, Germany

submitted by

Anne Bahrenberg
Veterinarian from Dortmund

Giessen 2014
With permission of the Faculty of Veterinary Medicine of
Justus-Liebig-University Giessen

Dean: Prof. Dr. Dr. h.c. Martin Kramer

Referee 1: Prof. Dr. Sabine Tacke

Referee 2: Prof Dr Joachim Geyer

Day of Disputation: 4th November 2014
Table of contents
Table of contents
Table of contents ................................................................................................................ I
Declaration ....................................................................................................................... III
Acknowledgements .......................................................................................................... IV
Abbreviations .................................................................................................................. VI
List of Figures ............................................................................................................... VIII
List of Tables .................................................................................................................... X
1 Introduction ....................................................................................................... 1
2 Literature review ............................................................................................... 4
2.1 Pain ..................................................................................................................... 4
2.1.1 The definition of pain .......................................................................................... 4
2.1.2 Peripheral nociception ......................................................................................... 5
2.1.3 Central nociception .............................................................................................. 7
2.1.4 Classification of pain ......................................................................................... 15
2.1.5 Physiological consequences of pain .................................................................. 19
2.2 Pain management ............................................................................................ 23
2.2.1 Epidural analgesia .............................................................................................. 23
2.3 Magnesium ....................................................................................................... 30
2.3.1 Magnesium physiology ...................................................................................... 30
2.3.2 Magnesium as a systemic analgesic .................................................................. 35
2.3.3 Magnesium as a neuraxial analgesic .................................................................. 36
2.4 Types of threshold testing ............................................................................... 40
2.4.1 Mechanical threshold testing ............................................................................. 43
3 Objectives and Hypotheses ............................................................................. 47
3.1 Objectives ......................................................................................................... 47
3.1.1 Primary objectives ............................................................................................. 47
3.1.2 Secondary objectives ......................................................................................... 47
3.2 Hypotheses ........................................................................................................ 47
3.2.1 Primary hypotheses ............................................................................................ 47
3.2.2 Secondary hypotheses ........................................................................................ 48
4 Material and Methods ..................................................................................... 49
I
Table of contents
4.1 Dogs ................................................................................................................... 49
4.2 Study design ..................................................................................................... 49
4.2.1 Anaesthesia ........................................................................................................ 50
4.2.2 Epidural catheter placement and drug administration ....................................... 50
4.2.3 Antinociceptive threshold testing using the von Frey device ............................ 51
4.2.4 Additional measurements .................................................................................. 55
4.3 Statistical analysis ............................................................................................ 56
5 Results ............................................................................................................... 58
5.1 Dogs ................................................................................................................... 58
5.2 Anaesthesia, epidural catheter placement and drug administration .......... 58
5.3 Antinocicpetive threshold testing using the von Frey device ....................... 59
5.3.1 Repeatability of the von Frey threshold ............................................................. 59
5.3.2 Antinocicpetive effects of the treatments .......................................................... 60
5.3.3 Changes in the antinociceptive threshold over time for regions ........................ 63
5.3.4 Changes in the antinociceptive threshold over time for treatments ................... 65
5.3.5 Changes in the antinociceptive thresholds over time in individual dogs for each
treatment ............................................................................................................ 73
5.3.6 Effect of side on the thresholds ......................................................................... 80
5.4 Additional measurements ............................................................................... 80
5.4.1 Sedation ............................................................................................................. 80
5.4.2 Behaviour........................................................................................................... 81
5.4.3 Motor effects ...................................................................................................... 82
5.4.4 Room temperature and humidity ....................................................................... 82
6 Discussion ......................................................................................................... 83
7 Conclusion ........................................................................................................ 92
8 Summary .......................................................................................................... 93
9 Zusammenfassung ........................................................................................... 95
10 References......................................................................................................... 97

II
Declaration
Declaration
I declare that I have completed this dissertation without the unauthorized help of a second
party and only with the assistance acknowledged therein. I have appropriately
acknowledged and referenced all text passages that are derived literally from or are based
on content of published or unpublished work of others, and all information that relates to
verbal communications. I have abided by the principle of good scientific conduct laid
down in the charter of the Justus-Liebig-University of Giessen in carrying out the
investigations described in the dissertation.

Giessen, Anne Bahrenberg

III
Acknowledgements
Acknowledgements
I would like to thank,
Dr Eva Rioja Garcia, for her trust in me, guidance, inexhaustible enthusiasm and support
during the whole project and beyond that. For introducing me into the world of research.
Dr. Sabine Tacke, for her willingness to support my external project.
Prof Geoffrey Fosgate for his patience explaining me statistics, his motivation and ideas.
Dr. Brighton Dzikiti, for his helping hand during data collection.
The staff at the University of Pretoria Biomedical Research Centre for their help and
support.
Mrs Kerstin Küster for helping me with the format and computer related queries.
My parents for their immeasurable support.

IV
Acknowledgements

In Erinnerung an meine Groβeltern

V
Abbreviations
Abbreviations
% Percent
AB Anne Bahrenberg
ACTH Adrenocorticotrophic hormone
ACVA American College of Veterinary
Anesthesiologists
AMPA Amino-3-hydroxy-5-methyl-4-
isoxazolepropionic acid
BD Brighton Dzikiti
Cm Centimetre
CNS Central nervous system
Co Control treatment
CO Carbon dioxide
2
Cp Carpal pad
CRF Corticotrophin releasing factor
CRI Constant rate infusion
CSF Cerebrospinal fluid
ER Eva Rioja-Garcia
G Gauge
gr Gram
GABA Gamma-aminobutyric acid
IQR Interquartile range
IV Intravenous
JCAHO Joint Commission on Accreditation of
Healthcare Organisations
kg Kilograms
Mt Metatarsus
mg Milligrams
Mg Magnesium treatment
Mg2+ Ionized magnesium
MgSO Magnesium sulphate
4
Mm Magnesium and morphine treatment
Mo Morphine treatment
mL Millilitre
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