Fluids and Electrolytes Demystified - part 1 pdf

CONTENTS AT A GLANCECHAPTER 1 Key Elements Underlying Fluid and Electrolyte Balance 3 CHAPTER 2 Key Elements Underlying Acid–Base Balance 19 CHAPTER 3 General Nursing Assessments and Di

Fluids and Electrolytes

Demystifi ed

Medicine is an ever-changing science As new research and clinical experience broaden our knowledge, changes in treatment and drug therapy are required The authors and the publisher of this work have checked with sources believed

to be reliable in their efforts to provide information that is complete and generally

in accord with the standards accepted at the time of publication However, in view of the possibility of human error or changes in medical sciences, neither the authors nor the publisher nor any other party who has been involved in the preparation or publication of this work warrants that the information contained herein is in every respect accurate or complete, and they disclaim all responsibility for any errors or omissions or for the results obtained from use of the information contained in this work Readers are encouraged to confi rm the information contained herein with other sources For example and in particular, readers are advised to check the product information sheet included in the package of each drug they plan to administer to be certain that the information contained in this work is accurate and that changes have not been made in the recommended dose or in the contraindications for administration This recommendation is of particular importance in connection with new or infrequently used drugs

Fluids and Electrolytes

Albany State UniversityAlbany, GeorgiaBennita W Vaughans, RN, MSN

Nurse RecruiterCentral Alabama Veterans Health Care System

Montgomery, Alabama

New York Chicago San Francisco Lisbon London

Madrid Mexico City Milan New Delhi San Juan

Seoul Singapore Sydney Toronto

Copyright © 2008 by The McGraw-Hill Companies, Inc All rights reserved Manufactured in the United States of America Except

as permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the publisher

0-07-159565-1

The material in this eBook also appears in the print version of this title: 0-07-149624-6.

All trademarks are trademarks of their respective owners Rather than put a trademark symbol after every occurrence of a trademarked name, we use names in an editorial fashion only, and to the benefit of the trademark owner, with no intention of infringement of the trademark Where such designations appear in this book, they have been printed with initial caps

McGraw-Hill eBooks are available at special quantity discounts to use as premiums and sales promotions, or for use in corporate training programs For more information, please contact George Hoare, Special Sales, at george_hoare@mcgraw-hill.com or (212) 904-4069

TERMS OF USE

This is a copyrighted work and The McGraw-Hill Companies, Inc (“McGraw-Hill”) and its licensors reserve all rights in and to the work Use of this work is subject to these terms Except as permitted under the Copyright Act of 1976 and the right to store and retrieve one copy of the work, you may not decompile, disassemble, reverse engineer, reproduce, modify, create derivative works based upon, transmit, distribute, disseminate, sell, publish or sublicense the work or any part of it without McGraw-Hill’s prior consent You may use the work for your own noncommercial and personal use; any other use of the work is strictly prohibited Your right to use the work may be terminated if you fail to comply with these terms

THE WORK IS PROVIDED “AS IS.” McGRAW-HILL AND ITS LICENSORS MAKE NO GUARANTEES OR WARRANTIES

AS TO THE ACCURACY, ADEQUACY OR COMPLETENESS OF OR RESULTS TO BE OBTAINED FROM USING THE WORK, INCLUDING ANY INFORMATION THAT CAN BE ACCESSED THROUGH THE WORK VIA HYPERLINK OR OTHERWISE, AND EXPRESSLY DISCLAIM ANY WARRANTY, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE McGraw-Hill and its licensors do not warrant or guarantee that the functions contained in the work will meet your requirements or that its operation will be uninterrupted or error free Neither McGraw-Hill nor its licensors shall be liable to you or anyone else for any inaccuracy, error or omission, regardless of cause, in the work or for any damages resulting therefrom McGraw-Hill has no responsibility for the content of any information accessed through the work Under no circumstances shall McGraw-Hill and/or its licensors be liable for any indirect, incidental, special, punitive, consequential or similar damages that result from the use of or inability to use the work, even if any of them has been advised of the possibility of such damages This limitation of liability shall apply to any claim or cause whatsoever whether such claim or cause arises in contract, tort or otherwise

DOI: 10.1036/0071496246

To my mother, who has been my most powerful role model.

To my husband Larry, my daughter Virginia, and

my son Larry, who love me unconditionally.

To my friends and family, who sustain me.

To my students, who provide my motivation to teach and to write.

ABOUT THE AUTHORS

Joyce Y Johnson, PhD, RN, CCRN, serves as dean of the College of Sciences and

Health Professions at Albany State University, with primary oversight for the graduate and graduate programs in the Department of Nursing and three additional departments Dr Johnson has been a nurse for over 30 years and a nurse educator for 25 years She received her bachelor’s of science in nursing from Vanderbilt University, her master’s in nursing from Emory University, and her PhD from the University of Mississippi Dr Johnson is author of many nursing textbooks and book chapters, articles, and monographs Her research areas are in curriculum trends in nursing programs and facilitating nursing student success, in addition to various clinical topics

under-Edward Lyons, PhD, is a professor of biology in the Department of Natural

Sci-ences at Albany State University in Albany, Georgia Dr Lyons has been a science educator for over 35 years and has taught biology and anatomy and physiology to many nursing students during his tenure Dr Lyons received his bachelor’s and master’s degrees from Howard University and his PhD in cell biology from Atlanta University

Bennita W Vaughans, RN, MSN, is a nurse recruiter at the Central Alabama

Veterans Health Care System She has been a nurse educator for over 20 years and has provided care to adults in many health care settings

Copyright © 2008 by The McGraw-Hill Companies, Inc Click here for terms of use

CONTENTS AT A GLANCE

CHAPTER 1 Key Elements Underlying Fluid and Electrolyte

Balance 3

CHAPTER 2 Key Elements Underlying Acid–Base Balance 19

CHAPTER 3 General Nursing Assessments and Diagnostic

Tests Related to Fluid, Electrolyte, and Acid–Base Balance 29

viii Fluids and Electrolytes Demystifi ed

CHAPTER 9 Phosphorus Imbalances: Hypophosphatemia

and Hyperphosphatemia 135

CHAPTER 10 Acid–Base Imbalances 147

PART THREE APPLICATIONS FOR FLUID AND

ELECTROLYTE CONCEPTS

CHAPTER 11 Multisystem Conditions Related to Fluid,

Electrolyte, and Acid–Base Imbalances 159

CHAPTER 12 Conditions Resulting in Fluid, Electrolyte,

and Acid–Base Imbalances 185 Answers to Final Check-ups 207 References 211 Index 213

Acknowledgments xv Introduction xvii

CHAPTER 2 Key Elements Underlying Acid–Base Balance 19

Learning Objectives 19 Overview 20 What Is pH? 20 Acids 21 Bases 22 Acid and Base Balance 23

CONTENTS

For more information about this title, click here

x Fluids and Electrolytes Demystifi ed

Regulation 23 Conclusion 25 Final Check-up 26

CHAPTER 3 General Nursing Assessments and Diagnostic

Tests Related to Fluid, Electrolyte, and Acid–Base Balance 29

Learning Objectives 29 Overview 30 Laboratory Test Units of Measure 31 Laboratory Tests Indicating Fluid Imbalance 32 Nursing Assessments for Fluid Imbalance 33 Laboratory Tests Indicating Acid–Base Imbalance 34 Acid–Base Balance Assessment 38 Laboratory Tests Indicating Electrolyte Imbalance 42 Nursing Assessments for Electrolyte Imbalance 43 Potassium 43 Sodium 46 Chloride 48 Calcium 49 Magnesium 51 Phosphate 52 Blood Urea Nitrogen and Creatinine 54 Conclusion 54 Case Situation 55 Final Check-up 57 References 58 Web Sites 58

IMBALANCES

CHAPTER 4 Fluid Volume Imbalances: Hypovolemia

Learning Objectives 61 Overview 62

Contents xi

Normal Intake and Output 63 Fluid Regulation 64 Fluid Circulation 64 Hypovolemia 66 Hypervolemia 72 Conclusion 75 Final Check-up 76 References 77

CHAPTER 5 Sodium Imbalances: Hyponatremia

and Hypernatremia 79

Learning Objectives 79 Overview 80 Sodium Regulation 81 Hypernatremia 84 Hyponatremia 87 Conclusion 92 Case Application 92 Final Check-up 94 References 95

CHAPTER 6 Potassium Imbalances: Hypokalemia

Learning Objectives 97 Overview 98 Hyperkalemia 100 Hypokalemia 103 Case Application 105 Conclusion 106 Final Check-up 107 References 109 Web Site 109

CHAPTER 7 Calcium Imbalances: Hypocalcemia

and Hypercalcemia 111

Learning Objectives 111 Overview 112 Hypocalcemia 113 Hypercalcemia 118 Conclusion 120 Final Check-up 120 Reference 122 Web Sites 122

CHAPTER 8 Magnesium Imbalances: Hypomagnesemia

and Hypermagnesemia 123

Learning Objectives 123 Overview 124 Hypermagnesemia 125 Hypomagnesemia 128 Conclusion 130 Case Application 132 Final Check-up 133 References 134 Web Site 134

CHAPTER 9 Phosphorus Imbalances: Hypophosphatemia

and Hyperphosphatemia 135

Learning Objectives 135 Overview 136 Hypophosphatemia 139 Hyperphosphatemia 142 Final Check-up 144 Web Sites 145

CHAPTER 10 Acid–Base Imbalances 147

Learning Objectives 147 Overview 148 Acidosis 148

xii Fluids and Electrolytes Demystifi ed

Alkalosis 151 Impact of Acid–Base Imbalances/Complications 153 Conclusion 153 Final Check-up 154 References 155 Web Site 155

PART THREE APPLICATIONS FOR FLUID AND

ELECTROLYTE CONCEPTS

CHAPTER 11 Multisystem Conditions Related to Fluid,

Electrolyte, and Acid–Base Imbalances 159

Learning Objectives 159 Overview 160 Age Extremes 162 Case Application 167 Renal Conditions 169 Case Application 173 Conditions with High Impact on Fluid Balance:

Burn Injury and Pregnancy 175 Case Application 180 Conclusion 183 Final Check-up 184

CHAPTER 12 Conditions Resulting in Fluid, Electrolyte, and

Acid–Base Imbalances 185

Learning Objectives 185 Heart Failure 186 Endocrine Conditions: Diabetes Insipidus,

Syndrome of Inappropriate ADH (SIADH), and Diabetes (Diabetic Ketoacidosis [DKA]

and Hyperosmolar Hyperglycemic Syndrome [HHS]) 191 Conclusion 202 Case Application 203 Final Check-up 205

xiv Fluids and Electrolytes Demystifi ed

Thank you to Lynnette Johnson for assistance in manuscript preparation.

Thank you to Bennita Vaughans for her contributions to the manuscript

Thank you to Dr Edward Lyons for lending his expertise to the project

Copyright © 2008 by The McGraw-Hill Companies, Inc Click here for terms of use

This page intentionally left blank

Fluids and Electrolytes Demystifi ed is a detailed overview of the critical concepts

involved in fl uid, electrolyte, and acid–base balance and imbalance, collectively one of the hardest topics to master in undergraduate nursing Fluid and electrolyte balance and acid–base balance have challenged students for ages Some of the diffi culty in understanding this content may lie in the attempt to remember each individual detail or symptom associated with an imbalance combined with the diffi culty of mastering the physiology involved in each process The list of symptoms

of imbalance can be extensive; there is often duplication and overlap between

electrolyte and acid–base imbalances In Fluids and Electrolytes Demystifi ed, the

normal functions are discussed to provide baseline data The concepts of imbalance are presented individually, but the links between concepts are addressed The reader

is led toward two facts: that many of the fl uid, electrolyte, and acid–base imbalance symptoms are interrelated and that the imbalances themselves are interlinked

Fluids and Electrolytes Demystifi ed is a detailed, easy-to-understand overview

of the concepts; it focuses on the information that students need most to understand the conditions that result in fl uid and electrolyte imbalances The book emphasizes the most critical information in fl uids and electrolytes by discussing the underlying mechanisms involved in maintaining fl uid, electrolyte, and acid–base balance and

by discussing the factors that fail and result in an imbalance

To promote understanding, there is coverage of the developmental changes and major conditions that result in fl uid, electrolyte, or acid–base imbalances The nursing assessments, interventions, and evaluations are reviewed to provide a whole

picture of the patient’s needs and nursing care situation Fluids and Electrolytes

Demystifi ed contains clear language and helpful features to guide the student

through application of concepts to real-life situations

The content in Fluids and Electrolytes Demystifi ed is organized as follows:

Chapters 1 and 2 are overview chapters that discuss the physiology involved in

fl uid, electrolyte, and acid–base balance Chapter 3 discusses the diagnostic tests and basic nursing assessments related to fl uid, electrolyte, and acid–base balance

Copyright © 2008 by The McGraw-Hill Companies, Inc Click here for terms of use

xviii Fluids and Electrolytes Demystifi ed

Chapter 4 focuses on fl uid volume imbalances (i.e., hypervolemia and hypovolemia) and related symptoms and treatments Chapters 5 through 9 present the major electrolytes and concepts related to excessive or insuffi cient blood levels of sodium, potassium, calcium, magnesium, and phosphate Chapter 10 focuses on acid–base imbalances and discusses the procedures needed to determine the underlying source

of the imbalance and the appropriate treatments and patient care needed to address the imbalance Chapters 11 and 12 contain presentations of developmental conditions and disease conditions that involve imbalances in fl uids, electrolytes, and acid–base, with the aim of enabling the reader to apply the concepts learned in earlier chapters of the book

The reader is encouraged to review Chapters 1 and 2 to refresh his or her knowledge

of the underlying processes involved in maintaining homeostasis through fl uid, electrolyte, and acid–base balance If the reader has a solid background in the physiology involved in these processes, Chapter 3 will be the best starting point Once the reader has completed a thorough review of the material dealing with imbalances, the conditions presented in Chapters 11 and 12 should be explored to promote integration of knowledge from these chapters into actual patient situations

The text features of Fluids and Electrolytes Demystifi ed are organized as follows:

• Each detailed chapter begins with a list of Learning Objectives, each of which is discussed further in the text

• Key terms are identifi ed for the content area These terms are boldface

when fi rst presented and defi ned in the chapter text to highlight them

• A brief overview of the topic is provided

• Content is divided into a brief review of normal function followed by detailed discussion of the imbalances that occur

• Lists and bullet points are used to present key facts

• Figures are provided to further illustrate concepts discussed in the text

• Tables are provided to highlight and summarize important details

• The “Speed Bumps” feature serves as a checkpoint that enables the reader

to quickly gauge his or her understanding after a portion of the information

is presented

• A conclusion summarizes the content of the chapter

• At the end of the chapter, a fi nal check-up consists of NCLEX-style

questions that test the reader’s retention of the information from the chapter.The reader is encouraged to become familiar with the key terms and their defi nitions because these are used throughout the book If, at any point in the overview, the content seems unfamiliar, the reader should review the more detailed