Download MSN LAP 3.1 - Canadian Valley Technology Center

CANADIAN VALLEY TECHNOLOGY CENTER
SCHOOL OF PRACTICAL NURSING
Course
Medical-Surgical Nursing
LAP Title
Medical-Surgical Patient Care Problems: Fluid,
Electrolyte, & Acid-Base Imbalances
LAP Objective
Upon completion of this LAP, you will be able to describe promotion and maintenance of fluid,
electrolyte & acid-base balances in the body. You will also be able to describe basic
pathophysiology, signs/symptoms, diagnostic testing, treatment, and nursing responsibilities of
fluid, electrolyte, and acid-base imbalances. This knowledge will be evidenced by scoring a
minimum of 80% on the written assignment and the two exams.
Specific Objectives:
1. Define key terms.
2. Review the following: various functions that fluid performs in the body; the body’s
mechanisms for fluid regulation; and three ways in which body fluids are continually being
distributed among the fluid compartments.
3. Distinguish the signs & symptoms of various electrolyte imbalances.
4. Discuss why the elderly have more problems with fluid and electrolyte imbalances.
5. Recognize the disorders that cause specific fluid and electrolyte imbalances.
6. Compare the major causes and signs & symptoms of acid-base imbalances.
7. Discuss interventions to correct an acid-base imbalance.
8. Review IV therapy and types of solutions.
9. Describe how to assess patients for signs of dehydration.
10. Correctly assess for edema & signs of over-hydration.
11. Apply knowledge of normal lab values in order to recognize electrolyte imbalances.
12. Distinguish among interventions to correct specific fluid & electrolyte imbalances.
References
deWit, Susan. Medical-Surgical Nursing Concepts & Practices. St. Louis: Elsevier. 2009.
deWit. Student Learning Guide for Med-Surg Nursing Concepts & Practices. St. Louis: Elsevier.
2009.
Cooper. Virtual Clinical Excursions (for your Med-Surg Nursing Concepts & Practice). St. Louis:
Elsevier. 2009.
Educational Global Technologies. Physiology: Promoting Fluid & Electrolyte Balance.
Educational Global Technologies. Physiology: Promoting Acid Base Balance.
LAP #
MSN 3.1
Written: 3/09 RR
Rev: 11/10; 1/11;
3/28/11 RR
Prerequisite
Theory Hours
Lab Hours
MSN 2.1
8
0
Objectives continued from previous page.
13. Determine if a patient has an acid-base imbalance.
14. Review measures to prevent the complications of IV therapy.
15. Compare interventions for the care of a patient receiving total parenteral nutrition (TPN)
with one undergoing IV therapy.
16. Evaluate pharmacological effects of medications used to treat vomiting and diarrhea.
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Fluid, Electrolyte, and Acid-Base Imbalances
MSN LAP 3.1
Please initial each blank
as you complete the step.
LEARNING STEPS
1. READ
LAP and Specific Objectives on cover sheet of this LAP.
2. STUDY
deWit Med-Surg, Chap. 3- Fluids, Electrolytes, Acid-Base Balance,
and Intravenous Therapy.
3. VIEW
On Evolve website (http://evolve.elsevier.com/deWit) or your MedSurg CD – the Fluid & Electrolytes Module.
4. COMPLETE
deWit Med-Surg Student Learning Guide, Chap. 3.
5. COMPLETE
Virtual Clinical Excursions, Lesson 1, pp. 43 – 51. Turn in for grade.
Label as MSN Assign. #5. Worth 2 points.
6. COMPLETE
Worksheet Questions on p. 3 – 5 of LAP. Do not hand in – study for
exam.
7. STUDY
Information Sheet #1 on pages 6 – 8 of this LAP.
8.
Go to the website www.wisc-online.com and complete the fluids and
electrolytes, Acid/Base Balance, and Differentiating Acid Base
Disturbances activities.
COMPLETE
9. COMPLETE
Online at www.edgt.com – Promoting Fluid and Electrolyte Balance.
Turn in for grades the results from each of the 6 tests – as MSN
Assign. grades #6, 7, 8, 9, 10 and 11.
10. COMPLETE
Online at www.edgt.com – Promoting Acid Base Balance. Turn in for
grades the results from each of the 3 tests for MSN Assign. grades
#12, 13, and 14.
11. COMPLETE
ABG Worksheet pp. 9-11 of LAP. DO NOT HAND IN.
12. COMPLETE
Bonus Review Questions & NCLEX-PN Exam Style Interactive
Review Questions @ http://evolve.elsevier.com/deWit (the bonus
review questions are on your CD but the NCLEX-PN style questions
are only available at the website.
13. REVIEW
All material in LAP of exam. Make certain you can answer all the
objectives.
14. TAKE
LAP Exam. If you score 80% or above, go on to next LAP. If not,
repeat this LAP.
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GRADES/EVALUATIONS:
 Assign. #5 (2 pts)
 Assign. #6 (1 pt)
 Assign. #7 (1 pt)
 Assign. #8 (1 pt)
 Assign. #9 (1 pt)
 Assign. #10 (1 pt)
 Assign. #11 (1 pt)
 Assign. #12 (1 pt)
 Assign. #13 (1 pt)
 Assign. #14 (1 pt)
 Exam #3 (34 pts)
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Fluid, Electrolyte, and Acid-Base Imbalances Worksheet
MSN-1 LAP 3.1
(Do Not Hand In)
1.
Describe the differences among isotonic, hypotonic, and hypertonic solutions. (See page
37 in your textbook.)
2.
Explain the 4 mechanisms the body uses to manage and control fluid balance? (See
page 35 in your textbook.)
3.
Explain the normal functions of ADH and aldosterone. (See page 35 in your textbook.
Review an anatomy text if necessary.)
4.
What is the function of the baroreceptors in the aortic arch? (See page 35 in your
textbook. Review an anatomy text if necessary.)
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5.
Which patients are at risk for deficient fluid volume? (See page 38 in your textbook.)
6.
List the signs and symptoms of deficient fluid volume. (See page 39 in your textbook.)
7.
What is a frequent cause of excessive loss of fluids? (See page 39 in your textbook.)
8.
How do hematocrit values change in patients who are over-hydrated? (See page 43 in
your textbook.)
9.
Name the four general causes of edema. (See page 43 in your textbook.)
10.
Describe the differences between hyponatremia and hypernatremia, including signs and
symptoms. (See page 45 in your textbook.)
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11.
What is hypercalcemia, and what are its signs and symptoms? (See page 49 in your
textbook.)
12.
Name the three mechanisms that control or try to rebalance pH. Explain how each
mechanism works. (See page 50 in your textbook.)
13.
What is the chain of events that results in hypocalemia for the patient in early renal
failure. (See page 59 in your textbook.)
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MSN 3.1
Information Sheet #1
Acid-Base Balance Overview
ACIDS
An acid is a substance that can release, or get rid of, hydrogen ions (H+). The body constantly
produces acids as a result of various bodily functions and metabolism.
Carbon Dioxide (CO2)
As we discuss acid-base balance, we will consider carbon dioxide (CO2) to be an acid,
even though by itself it does not have any hydrogen (H) to release. It is considered to be
an acid because in the body, it bonds with water and forms an acid.
When a molecule of carbon dioxide (CO2) combines, or bonds, with a molecule of water
(H2O) there will then be: one C (carbon), two H (hydrogen) and three O (oxygen). This
forms carbonic acid (H2CO3). Carbonic acid does have the ability to release hydrogen
ions, thus it is an acid.
Because there is not a way to measure carbonic acid and we can measure carbon
dioxide, we use the carbon dioxide measurement for the acid component.
BASES OR ALKALIS
A base or alkaline substance is one that can bond with a hydrogen ion and produce a difference
substance.
Bicarbonate (HCO3)
The common base/alkaline substance assessed to determine acid-base balance is
bicarbonate (HCO3).
pH
The ratio between hydrogen (H) ions and bicarbonate (HCO3) ions must be maintained at a
specific ratio of 20:1 (20 bicarbonates to 1 acid) to keep the body’s pH at a level that will sustain
life. The pH is the number scale that represents this level of acidity versus the level of alkalinity
of the body fluid.
Hydrogen ions (H+) and hydroxide ions (OH-) are found in all water solutions. When there is an
equal number of hydrogen and hydroxide ions, the solution is "neutral". If there are more
hydrogen ions (H+) than hydroxide ions(OH-), the solution is acid. If there are more hydroxide
ions (OH-) than hydrogen ions (H+), the solution is alkaline (base). The scale we use to
measure this concentration is called the pH scale. It is a scale from 0-14, with 7 being neutral.
Anything above 7 is alkaline (base). Anything below 7 is acidic. The higher the concentration of
hydrogen ions (H+), the lower it's pH, the more acidic the solution. The lower the concentration
of hydrogen ions (H+), the higher it's pH, the more alkaline (base) the solution.
ACID BASE BALANCE
To maintain acid-base balance, a balance of the hydrogen ion (H+) and bicarbonate (HCO3)
concentration in the body's extracellular fluids must be maintained. The hydrogen ion
concentration is determined by the ratio of carbonic acid (H2CO3) to bicarbonate (HCO3) or
sodium bicarbonate (NaHCO3) in the extracellular fluid. Please note that bicarbonate and
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sodium bicarbonate may be used interchangeably. The only difference in their chemical
names is the "Na" for the sodium. The ratio to maintain balance is 20 parts bicarbonate
(HCO3) to 1 part carbonic acid (H2CO3). The extracellular fluid is used to measure our pH is the
arterial blood. The normal pH of blood falls within a very narrow range: between 7.35 and 7.45
which is slightly alkaline. Anything above 7.45 is too alkaline (base). Anything below 7.35 is too
acidic. The body works very hard to maintain the pH within this narrow range, to keep everything
balanced, to maintain homeostasis. It uses three systems to accomplish this feat: the bufferpairs system, the respiratory system, and the urinary system.
BUFFER-PAIRS SYSTEM
There are four buffer pairs in the body, but the one that is most important is the bicarbonate and
carbonic acid pair. They are like "chemical sponges". They work within a fraction of a second to
help prevent an excessive change in the hydrogen ion (H +) and hydroxide ion (OH-) balance.
They circulate throughout the body in pairs, combining with strong acids and alkaline
substances, which means they neutralize the excess acids and alkalis. If there are too many
OH- ions, there will be too much bicarbonate produced, allowing it to dominate and make the
solution too alkaline. If there are excessive H+ ions, too much carbonic acid will form and the
blood will become too acidic.
RESPIRATORY SYSTEM
Carbonic acid (H2CO3) is formed when carbon dioxide (CO2) bonds with a molecule of water
(H20). If there is an increase or a decrease of carbonic acid (H2CO3), the pH is affected. So,
the respiratory system plays a big role in the acid side of pH balance. The lungs can "blow off”
too much carbon dioxide (CO2), which then decreases the amount of carbonic acid (H2CO3)
which can be formed, making the pH more alkaline. Or the lungs can retain more carbon
dioxide (CO2), which allows more carbonic acid (H2CO3) to form, making the pH more acidic.
So, if the blood is too acidic due to a cellular or kidney dysfunction, the lungs attempt to
compensate by increasing the respiratory rate blowing off more carbon dioxide (CO2). If a
cellular or kidney problem cause the blood to be too alkaline, the lungs will try to compensate
and maintain the pH by slowing the respiratory rate This will cause more carbon dioxide (CO2)
to be retained in the blood and allow more carbonic acid (H2CO3) to form. This will help return
the alkaline pH back to neutral. The lungs are quick to react but they change the pH in smaller
increments than the urinary system.
URINARY SYSTEM
The kidneys play an important role in maintaining pH balance. They are the most effective in
controlling pH, though they are the slowest, taking hours to days. They are usually the last but
best defense against pH changes. They have selective control over excreting or retaining
varying amounts of acid in the form of hydrogen ions (H+) or excreting or retaining varying
amounts of base in the form of bicarbonate (HCO3). If the blood is too acidic, the kidneys help
maintain balance by excreting a higher amount of hydrogen (H+), which helps get rid of the acid.
Plus, the kidney will help neutralize the excess acid by retaining bicarbonate (HCO3). If the
blood is too alkaline, the kidneys help to compensate and restore balance by excreting more
bicarbonate and retaining the hydrogen. This increases the acidity which neutralizes the
excessive alkalinity.
These three systems must all work together to maintain homeostasis for life to be
sustained. They all have a common goal: to keep the arterial blood pH between 7.35 and 7.45.
IMPORTANT POINTS TO REMEMBER
pH Scale
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1.
2.
3.
4.
5.
pH measures the hydrogen concentration.
7 is neutral.
Above 7 is alkaline-the higher up the scale, the more alkaline it is.
Below 7 is acid-the lower down the scale, the more acidic it is.
The higher the hydrogen ion concentration, the more acidic it is, & the lower the pH.
Acid-base Balance
1. The acid-base balance of the body is measured by it's pH.
2. The arterial blood is where we measure this pH.
3. The normal range of arterial blood pH that must be maintained is between
7.35 and 7.45, slightly alkaline.
Buffer Pairs
1. Carbonic acid and sodium bicarbonate (bicarbonate) is the most important buffer pair.
2. For acid base balance to be maintained, the bicarbonate (HCO3) and carbonic acid
(H2CO3) ratio must be maintained at a 20:1 ratio (20 parts bicarbonate & 1 part carbonic
acid).
3. Carbonic acid and bicarbonate work as "chemical sponges" to help neutralize pH changes
in an attempt to prevent large changes in pH.
Respiratory System
1. Quick to react but less effective than the urinary system.
2. Is able to excrete or retain acid only, in the form of carbon dioxide (CO2).
Urinary System
1. Last to kick in, takes the longest (hours to days), but is the most effective system in
maintaining pH balance.
2. Is able to excrete or retain acid in the form of hydrogen.
3. is able to excrete or retain base in the form of bicarbonate.
Researched 10/98 by Linda Ludwig, BS, RN, Practical Nursing Instructor, Canadian Valley Technology
Center, Chickasha, Ok.
Revised 7/2010 by Linda Ludwig, RN, BS, MEd.
Resources: Fluids & Electrolytes Made Incredibly Easy. Springhouse Corp. Springhouse, Pa. 1997.
Thibodeau & Patton. The Human Body in Health & Disease. 2nd Ed. Mosby-Yearbook, Inc. St. Louis, Mo.
1997.
deWit, Susan. Medical-Surgical Nursing Concepts & Practice. St. Louis: Elsevier, 2009.
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MSN-1 LAP 3.1
ABG Worksheet (DO NOT HAND IN)
Name____________________________ Date___________________Grade____________
Normal ranges: pH: 7.35 – 7.45
CO²: 35-45
HCO³: 22-26
Interpret the following blood gases.
1.
pH -7.32
CO²- 49
HCO³-26
pH is: ____________________ (WNL [balanced], low [acidosis], or high [alkalosis]?)
CO² is: ____________________ (WNL, high causing acidosis, or low causing alkalosis?)
HCO³ is: ___________________ (WNL, low causing acidosis, or high causing
alkalosis?)
Answer: ____________________________________
2.
pH -7.48
CO²-31
HCO³-31
pH is: ____________________ (WNL [balanced], low [acidosis], or high [alkalosis]?)
CO² is: ____________________ (WNL, high causing acidosis, or low causing alkalosis?)
HCO³ is: ___________________ (WNL, low causing acidosis, or high causing
alkalosis?)
Answer: ____________________________________
3.
pH-7.51
CO²-29
HCO³-23
pH is: ____________________ (WNL [balanced], low [acidosis], or high [alkalosis]?)
CO² is: ____________________ (WNL, high causing acidosis, or low causing alkalosis?)
HCO³ is: ___________________ (WNL, low causing acidosis, or high causing
alkalosis?)
Answer: ____________________________________
4.
pH-7.29
CO²-37
HCO³-27
pH is: ____________________ (WNL [balanced], low [acidosis], or high [alkalosis]?)
CO² is: ____________________ (WNL, high causing acidosis, or low causing alkalosis?)
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HCO³ is: ___________________ (WNL, low causing acidosis, or high causing
alkalosis?)
Answer: ____________________________________
5.
pH-7.33
CO²50
HCO³-25
pH is: ____________________ (WNL [balanced], low [acidosis], or high [alkalosis]?)
CO² is: ____________________ (WNL, high causing acidosis, or low causing alkalosis?)
HCO³ is: ___________________ (WNL, low causing acidosis, or high causing
alkalosis?)
Answer: ____________________________________
6.
pH-7.30
CO²-47
HCO³-19
pH is: ____________________ (WNL [balanced], low [acidosis], or high [alkalosis]?)
CO² is: ____________________ (WNL, high causing acidosis, or low causing alkalosis?)
HCO³ is: ___________________ (WNL, low causing acidosis, or high causing
alkalosis?)
Answer: ____________________________________
7.
pH-7.49
CO²-40
HCO³-29
pH is: ____________________ (WNL [balanced], low [acidosis], or high [alkalosis]?)
CO² is: ____________________ (WNL, high causing acidosis, or low causing alkalosis?)
HCO³ is: ___________________ (WNL, low causing acidosis, or high causing
alkalosis?)
Answer: ____________________________________
8.
pH-7.45
CO²-30
HCO³-19
pH is: ____________________ (WNL [balanced], low [acidosis], or high [alkalosis]?)
CO² is: ____________________ (WNL, high causing acidosis, or low causing alkalosis?)
HCO³ is: ___________________ (WNL, low causing acidosis, or high causing
alkalosis?)
Answer: ____________________________________
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9.
pH-7.31
CO²-46
HCO³-20
pH is: ____________________ (WNL [balanced], low [acidosis], or high [alkalosis]?)
CO² is: ____________________ (WNL, high causing acidosis, or low causing alkalosis?)
HCO³ is: ___________________ (WNL, low causing acidosis, or high causing
alkalosis?)
Answer: ____________________________________
10.
pH-7.51
CO²-44
HCO³-28
pH is: ____________________ (WNL [balanced], low [acidosis], or high [alkalosis]?)
CO² is: ____________________ (WNL, high causing acidosis, or low causing alkalosis?)
HCO³ is: ___________________ (WNL, low causing acidosis, or high causing
alkalosis?)
Answer: ____________________________________
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