Clinical Management of Electrolyte Disorders

214 Pages·1983·4.568 MB·English

by  Mary G. McGeown MD, PhD, FRCP, FRCP Ed, FRCPI (auth.)

CLINICAL MANAGEMENT OF ELECTROLYTE DISORDERS
DEVELOPMENTS IN CRITICAL CARE
MEDICINE AND ANESTHESIOLOGY
Other volumes in this series:
Prakash, Omar (ed.): Applied Physiology in Clinical Respiratory Care. 1982.
ISBN 90-247-2662-X.
McGeown, Mary G.: Clinical Management of Electrolyte Disorders. 1983.
ISBN 0-89838-559-8.
Klain, Miroslav: High Frequency Ventilation.
Scheck, P.A., Sjostrand, U.H., and Smith, R.B. (eds.): Perspectives in High Fre
quency Ventilation. 1983. ISBN 0-89838-571-7.
Stanley, Th.H. and Petty, W.C. (eds.): New Anesthetic Agents, Devices and Monitor
ing Techniques. 1983. ISBN 0-89838-566-0.
CLINICAL MANAGEMENT
OF ELECTROLYTE
DISORDERS
by
MARY G. McGEOWN, MD, PhD, FRCP, FRCP Ed, FRCPI
Renal Unit, Belfast City Hospital
Belfast
1983 MARTINUS NIJHOFF PUBLISHERS
a member of the KLUWER ACADEMIC PUBLISHERS GROUP
BOSTON / THE HAGUE / DORDRECHT / LANCASTER
Distributors
for the United States and Canada: Kluwer Boston, Inc., 190 Old Derby Street,
Hingham, MA 02043, USA
for all other countries: Kluwer Academic Publishers Group, Distribution Center,
P.O.Box 322,3300 AH Dordrecht, The Netherlands
Library of Congress Cataloging in Publication Data
McGeown, Mary G.
Clinical management of electrolyte disorders.
(Developments in critical care medicine and
anesthesiology)
Bibliography: p.
1. Water-electrolyte imbalances--Treatment.
2. Electrolyte therapy. 3. Intravenous therapy.
I. 'Ii tle. II. Series. [DNLM: 1. Water-electrolyte
imbalance--Therapy. WD 220 M478cl
Rc630.M4 1983 616 82-19012
ISBN -13: 978-94-009-6701-4 e-ISBN -13: 978-94-009-6699-4
DOl: 10.1007/978-94-009-6699-4
Copyright
© 1983 by Martinus Nijhoff Publishers, Boston.
Softcover reprint of the hardcover 1s t edition 1983
All rights reserved. No part of this publication may be reproduced, stored in a
retrieval system, or transmitted in any form or by any means, mechanical,
photocopying, recording, or otherwise, without the prior written permission of
the publishers,
Martinus Nijhoff Publishers, 190 Old Derby Street, Hingham, MA 02043, USA.
To my husband, Max Freeland
Preface
Serious disturbances of fluid and electrolyte balance are frequently encountered in
acutely ill patients; somewhat less often in the chronically sick. There seems to be a
trend for such cases to increase, due probably to an increase in major surgical
procedures on older patients whose renal function is less than adequate.
There are already many publications dealing with the physiology of the homeo
stasis of fluid and electrolytes, and others dealing with the clinical aspects of the
subject. It is often assumed that a knowledge of the basic principles of physiology
will enable the doctor to prescribe suitable intravenous therapy. In practice this is
often found not to be so and the evidence for this is the frequency of calls for help
with electrolyte problems from well-qualified and experienced doctors who are
undoubtedly equipped with adequate or even excellent knowledge of the basic
principles involved. It is not an unusual observation that knowledge of theory and
principles does not necessarily lead to successful practice in this or any other art or
craft.
Most doctors already possess knowledge of the physiology of the internal envi
ronment, but some are aware of being unable to deal effectively with clinical
problems related to fluid and electrolyte disturbances and seek guidance to translate
theoretical knowledge into practice.
This book is offered, not without diffidence, to those who experience the need for
a simple manual on intravenous therapy, emphasizing the clinical aspects of the
work rather than the basic physiology and biochemistry. For deeper study many
excellent texts are available, a useful selection of which is given in the accompanying
bibliography.
Belfast Mary G. McGeown
June 1982
Acknowledgements
c.c.
I am happy to acknowledge the generous help of friends and colleagues. Dr
Doherty read the second draft and made many useful suggestions. Dr D. Neill's
comments on Chapters I and 7 were helpful and Mr S. Nesbitt gave invaluable
detailed help with these chapters.
I am grateful to Doctors E. Whitehead, C. Farnan and P. Freeland for their help
with correction of the final text.
I wish to thank Mrs Sylvia Crowe for her patience and for her careful typing of the
text.
Write the vision, and make it plain upon tables,
that he may run that readeth it
Habakkuk ii, 2
Table of contents
Preface VII
1. Basic infonnation relating to body fluids
1. Volume I
2. Solutes
3. Mole I
4. Solution 2
5. Equivalent 3
6. Osmosis 3
7. Osmotic pressure 3
8. Osmolarity, osmolality 3
8.1. Osmolarity 4
8.2. Osmolality 4
9. Isotonicity, hypertonicity, hypotonicity 4
10. Oncotic pressure 4
11. Cell membrane pumps 5
12. Role of enzymes 5
13. Acid/base 5
13.1. Acidosis 7
13.2. Alkalosis 7
13.3. Buffers 7
13.4. Anion gap 8
13.5. Regulation of acid/base 8
13.5.1. Regulation of acid/base by the kidneys 9
13.5.2. Regulation of acid/base by the lungs 11
14. Osmotic diuresis 12
15. Free-water clearance 12
15.1 Effect of volume depletion in chronic renal failure 13
15.2. Polyuria 13
16. Antidiuretic honnone 13
17. Aidosterone 14
17.1. Hyperaldosteronism 14
17.2. Hyporeninaemic hypoaldosteronism 14
XII
2. The fluid compartments of the body 15
1. Fluid compartments 15
2. Composition of plasma and intracellular fluid 16
3. Role of the cell membrane pumps 16
3. What can intravenous therapy accomplish? 18
1. Use of intravenous therapy 18
2. Limitations of intravenous therapy 18
2.1. Limitation of volume 18
2.1.1. Amount of fluid loss 18
2.1.2. Age 18
2.1.3. Cardiac and renal function 19
2.1.4. Time 19
2.1.5. Previous intravenous therapy 19
3. Limitation of osmolality 19
4. Limitation of sodium 19
4.1. Sodium space 20
5. Limitation of hydrogen ion concentration 21
5.1. Respiratory acidosis/alkalosis 21
5.2. Metabolic acidosis 22
5.3. Metabolic alkalosis 22
6. Potassium deficiency 23
4. The clinical history 24
1. Deficient intake 24
2. Vomiting or aspiration 24
3. Loss from gastrointestinal fistulae 26
4. Loss of bile 26
5. Diarrhoea 26
6. Excessive urinary loss 27
7. Impaired renal function 27
8. Urinary diversion operations 27
9. Excessive loss of sweat 28
10. Drug-induced electrolyte disturbances 28
11. Electrolyte disturbances associated with intravenous therapy 31
12. Thirst 32
13. Dyspnoea 32
5. Physical examination of the patient 33
1. Weight 33
2. Temperature 34
3. Skin 34
4. Sweating 35