fluid and electrolytes
DESCRIPTION
Excellent workbook about fluid and electrolytes with exercises to reinforce learning. provided by VCH.TRANSCRIPT
FFFllluuuiiiddd
AAAnnnddd EEEllleeeccctttrrrooolllyyyttteeesss
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
1
Developed by Joanne Beestra, December 1988 Revised by Cindy Hartley & Laurie McLauchlin, September 2008
TABLE of CONTENTS
Learning Outcomes for the Module and the Workshop…………………… 3
Introduction……………………………………………………........................ 4
General Principles of Fluid & Electrolyte Imbalance……………………….. 6
Identify Patients at Risk……………………………………………………….. 7
Diffusion and Osmosis………………………………………………….......... 9
Assess Volume Status………………………………………………………… 11
Serum Electrolytes…………………………………………………………….. 12
Additional Assessments……………………………………………………….. 15
Volume Imbalance……………………………………………………………… 16
Volume Deficit…………………………………………………………………… 17
Treatment for Volume Deficit………………………………………………….. 20
Volume Excess…………………………………………………………………. 22
Treatment for Volume Excess………………………………………………… 23
Appendix A……………………………………………………………………… 25
References……………………………………………………………………… 27
Answer Key……………………………………………………………………… 28
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
2
DIRECTIONS
This module is a pre-requisite activity for the VCH Acute Medical & Surgical
Nursing (AMSN) Program AMSN - Level 2 Fluid & Electrolytes Workshop. As
you work through this module please complete the exercises to enhance your
learning. If you are having difficulty with any section please contact your Nurse
Clinician and/or Clinical Educator for assistance. The module will take
approximately two hours to complete.
Exercises are indicated by the following icon:
LEARNING OBJECTIVES (Learning Module and Workshop)
Before you begin this module please review the glossary found in Appendix A on
page 25 and ensure you have a solid understanding of the terms used within this
module. In addition, please review the anatomy & physiology of the renal system,
the gastrointestinal (GI) system, and the neuroendocrine system and their role in
fluid and electrolyte balance.
At the end of the learning module and workshop, you will have participated in a
review of Fluid and Electrolytes (F & E) allowing you an opportunity to apply your
knowledge and skills addressing F & E imbalances commonly seen in an acute
medical/surgical setting.
Specifically, you will:
1. Accurately interpret lab results in relation to fluid and electrolyte balance. 2. Articulate key electrolytes and symptoms of imbalance.
3. Identify and explain appropriate intravenous solutions related to patient
condition.
4. Identify patients who are at risk for disturbance of fluid and electrolytes.
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
3
INTRODUCTION
What are we talking about when we mention fluids and electrolytes? Fluid refers
to body fluid which is water and substances dissolved in water such as
electrolytes, non-electrolytes, acids, bases, and proteins. The regulation of the
body’s water is controlled by hydrostatic pressure, osmotic pressure and
hormones.
Electrolytes refer to charged particles found in body fluids that are required for
the transmission of electrical impulses for proper nerve, heart and muscle
function (Astle 2005).
Every organ system in the body participates in fluid and electrolyte regulation and
every organ system relies on fluid and electrolyte balance for normal function.
The body works very hard to maintain fluid and electrolyte balance. When
imbalance occurs, a number of compensatory mechanisms are available to
restore balance. When a patient becomes acutely ill it becomes increasingly
difficult for the body to compensate which means a fluid and electrolyte
imbalance can become rapidly life threatening.
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
4
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
5
Poor fluid balance management as well as poor documentation of fluid balance
records have been recognized as contributing factors in poor patient outcomes
(Scales & Pilsworth 2006). The ability to recognize and respond to actual or
potential imbalance is a key aspect of your nursing assessment.
The goal of this module and the workshop is to further develop your skills in
recognizing normal and abnormal physiology of fluid and electrolytes thereby
increasing your ability to respond prior to an imbalance in either fluid balance
and/or electrolyte imbalance becoming life threatening.
GENERAL PRINCIPLES OF FLUID & ELECTROLYTE IMBALANCE
There are three basic categories of fluid and electrolyte disturbance:
Volume Imbalance is a loss or gain of isotonic fluid
Concentration Imbalance is a loss or gain of hypotonic fluid
Composition Imbalance is a loss or gain of electrolytes Although each of these imbalances may be present simultaneously, they are
separate entities and must be considered as such when undertaking diagnosis
and treatment. For practical purposes, these imbalances occur first in the
extracellular (interstitial and intravascular) compartment. The intracellular
compartment may not be affected.
When we talk about fluids we must also consider intravenous (IV) fluids, most
hospitalized patients have some form of IV fluid therapy (David, 2007) initiated.
There are several different reasons why patients require IV fluid, it may be to
maintain a water balance or it may be to replace lost fluids. Whatever the reason
you need to know why your patient is receiving therapy to ensure that they are
receiving the correct type of fluid.
Assessment
Assessment of fluid and electrolyte balance is based on determining the quantity
(volume) of fluid in the patient followed by a determination of the quality
(concentration and composition) of the fluid.
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
6
Identify patients at risk
Virtually any disease or injury is capable of producing a disturbance in fluid and
electrolyte equilibrium. Imbalance may occur as a primary effect of the disease;
as a result of compensation to the disease; or, as a result of therapy for the
disease. Because the GI tract, the renal system, and the neuroendocrine system
are the major organs of fluid and electrolyte homeostasis, any disease or therapy
affecting these organs will have an immediate impact on fluid and electrolyte
balance. For example, acid-base status affects both renal excretion and internal
distribution of potassium, calcium and chloride; the integrity of the cell membrane
influences distribution of electrolytes and water between the intracellular and
extracellular compartments; metabolism of glucose impacts on cellular uptake of
potassium and phosphate as well as water balance and so forth.
As you review your patient’s history and current clinical status ask yourself the
following questions:
1. Does the patient have any disease that would cause a fluid and electrolyte
imbalance? If so, what imbalance is most likely to occur?
2. Is the patient receiving any medication or therapy that would cause a fluid
and electrolyte imbalance? Be very suspicious of patients receiving
diuretic therapy.
3. Is there an abnormal loss of body fluid? Where are the losses coming
from? Does the fluid contain electrolytes and if so, which ones?
4. How does the total intake of fluid compare to the total fluid output?
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
7
Where do we store body fluids?
There are three compartments can you name them?
1. ___________________________________________________________
2. ___________________________________________________________
3. ___________________________________________________________
Intravascular and interstitial are considered Extracellular
Self Check
1. Fluid inside the cell is _________________________________________
2. Fluid outside the cell is ________________________________________
3. Extracelluar fluid is divided into ______________ and ________________
Body fluids are made up of dissolved substances and a good example of this
would be sodium chloride. When added to a solution it separates into Sodium
(Na+) and Chloride (Cl-). A positive charge is a cation and a negative charge is
called an anion, to maintain balance there has to be an equal number of positive
and negative ions. The fluid in each compartment contains electrolytes which are
measured in milliequivalents (mEq)/L. Each of these compartments has its own
unique composition of electrolytes. A specific kind and amount of certain
electrolytes must be available for normal cell function (Weldy 1996).
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
8
If potassium is lost from a cell what is the danger?
Each compartment is surrounded by a semipermeable membrane, this allows for
mixing of extracellular (EC) fluids and intracellular (IC) fluids. These membranes
are considered selectively permeable in the fact that they allow some substance
through but not all. For example water moves freely through all fluid
compartments but the particles dissolved in the water (solutes) for example
sodium or chloride may not be able to pass.
DIFFUSION There are different mechanisms within the body that allow for movement of
solutes through the body. This movement is from an area of higher concentration
to an area of lower concentration. One such mechanism is diffusion. Diffusion
occurs within the fluid compartments and from one compartment to another if the
membrane allows. This is also referred to as simple diffusion. Sometimes solutes
need help to get across a membrane, or they need a carrier substance, this is
known as facilitated diffusion.
OSMOSIS Osmosis is defined as the movement of water across a membrane. During the
process of osmosis the water will move to the higher concentration of solute (a
lower concentration of water).
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
9
When the concentration is equal on
both sides it is considered isotonic.
Therefore when giving an isotonic IV
fluid such as 0.9% Normal Saline
(NS) there will be no fluid shift into or
out of the cells.
When a solution contains a lower
concentration of salt it is called
hypotonic. Two common hypotonic
solutions are 0.45% Normal Saline (NS)
and Dextrose 5% in Water (D5W). With
this type of solution the water will shift
out of the vascular bed and into the
cells.
Hypertonic fluids which have more
solute than the body’s water will pull the
water from the cells and interstitial
spaces and back into the circulation.
This can shrink cells.
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
10
Diffusion and Osmosis are passive processes; there is a flow from a higher
concentration to a lower concentration without any expenditure of energy from
the cells. With the active transport system you require energy or adenosine
triphosphate (ATP), as you are moving from a lower concentration to a higher
concentration. An example would be the sodium potassium pump, where the
potassium is greater inside the cell than outside. Sodium, potassium, calcium,
and magnesium all require active transport to move across the membrane.
ASSESS VOLUME STATUS
Volume disorders affect the intravascular and interstitial spaces and signs and
symptoms of volume imbalance will reflect changes in these:
1. Blood Pressure (BP): Hypotension reflects ____________________;
whereas hypertension reflects ____________________.
2. Heart Rate (HR): The HR will ____________________ in response to
volume deficit and may ____________________ in response to volume
excess
3. Pulse Quality: A full bounding pulse is seen in ____________________ ;
and a weak, thready, obliterated pulse occurs with __________________
4. Filling Pressures: Central Venous Pressure (CVP) will be ___________
in response to volume excess and would be ______________ in response
to volume deficit.
Assess Concentration Status:
The concentration of body fluid is determined primarily by _________ although
other substances that exert an osmotic force – especially serum glucose – may
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
11
impact as well. Concentration imbalances affect the intracellular compartment,
especially the cerebral cells:
Serum Sodium: Will be ____________in hypertonic states and ____________
in hypotonic states
Assess Neuromuscular Status:
Cellular edema associated with hypotonicity appears as neuromuscular
irritability; cellular dehydration associated with hypertonicity appears as
neuromuscular depression.
The acutely ill patient may have a decreased level of consciousness or be
irritable for any number of reasons.
Correlate the serum sodium with the clinical presentation.
ASSESS THE COMPOSITIONAL STATUS
Serum Electrolytes
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
12
Serum electrolytes should be monitored as ordered. In general, sodium,
potassium, hematocrit, glucose, BUN and creatinine are the most frequently
monitored. In the critically ill patient, serum electrolyte monitoring is performed
frequently as the patient’s condition warrants. For the acutely ill patient on the
other hand, they may have bloodwork monitored on a daily basis or perhaps as
needed (prn). Magnesium, calcium and serum proteins are monitored on a prn
basis. The patient should have “baseline” bloodwork drawn on admission, and
post-op day 1 following surgical procedures. Remember to include your patient’s
bloodwork results as part of your physical assessment especially if you have
identified the patient as being high risk for imbalance.
What are the normal values for the following electrolytes and
bloodwork?
Sodium ____________________________________________________
Potassium__________________________________________________
Calcium____________________________________________________
Magnesium__________________________________________________
Chloride___________________________________________________
BUN_______________________________________________________
Creatinine___________________________________________________
Hematocrit__________________________________________________
Glucose____________________________________________________
Arterial Blood Gas Analysis
pH__________
PaCO²__________
PaO²__________
HCO³__________
SaO²__________
SpO²__________
What are plasma proteins? __________________________________________
Can you name them and add normal values? ____________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
________________________________________________________________
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
13
What is the difference between these 2 parameters? __________________ ______________________________
When only one component of fluid and electrolyte balance is disturbed, it is fairly
easy to identify the imbalance. However, some acutely ill patients have mixed
imbalances. Be aware of the following common patterns as you analyze your
patient’s lab results:
What’s my problem? _________________________________
Na+ 165
K+ 5.0
BiCarb 30
BUN 18
Glucose 5.5
Creatinine 140
What’s my problem? __________________________________
Na+ 135
K+ 7.0
BUN 28
Glucose is 5. 5
Creatinine 900
Compositional disorders primarily affect excitable cells such as the muscle,
nerves and cardiac cells. Neuromuscular irritability or depression may be masked
or be caused by other clinical conditions. The ECG may reflect some
compositional imbalances, especially a potassium imbalance.
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
14
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
15
ADDITIONAL ASSESSMENTS
Renal function Renal function as reflected by urine output may be a symptom or cause of fluid
and electrolyte imbalance. Hypovolemia is the most common cause of decreased
urine output but it may also be caused by oliguric renal failure or an excess of
anti-diuretic hormone (ADH). A urine output of less than 30 ml/hour should be
investigated. A general rule of thumb for a healthy adult is 1mL/kg/hr (Scales,
Pilsworth 2008).
High urine output may occur with hypervolemia but it may also be caused by but
not limited to hyperglycemia, renal failure in the diuretic phase, or inadequate
ADH. Generally speaking, the hourly urine output is a good overall guide to fluid
balance.
Intake and Output
A record of intake versus a record of output is determined for each shift and
calculated daily. A cumulative balance of fluid gains and losses determines the
response to therapy. Continued gain or loss that is not explained by therapy (i.e.
volume change, diuretics) or normalization process (diuresis on 3rd postoperative
day) should be investigated.
Daily Weights
If this is a routine assessment parameter for your patient population it should be
done at the same time everyday, using the same scale and the patient should
have an empty bladder. Rapid weight gain or loss usually indicates changes in
fluid balance. A weight gain may be associated with a fluid shift from the
intravascular space to the interstitial space and is, therefore not a reliable
indicator of intravascular volume status.
VOLUME IMBALANCE Volume imbalance is an excess or deficit of water and electrolytes in the
extracellular (EC) compartment. Because the chief electrolyte of the EC fluid is
sodium, volume imbalance is primarily a loss or gain of sodium
When an isotonic saline solution is lost from or added to body fluid, only the
VOLUME of the EC compartment is changed. Intracellular (IC) volume will not be
affected because osmolarity or tonicity remains the same between the IC and EC
compartment.
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
16
Because there are no changes in concentration or composition of the EC fluid,
there are no readily available lab tests to aid in the diagnosis of volume
imbalance. Therefore, diagnosis is made on the basis of clinical signs and
symptoms. Signs and symptoms of volume imbalance usually appear first in the
intravascular space and are reflected as changes in blood pressure and
hemodynamic values. Symptoms associated with interstitial volume imbalance;
for example edema; generally occur later unless the change is rapid and severe.
VOLUME DEFICIT
Hypovolemia may result from either internal or external loss of isotonic fluid from
the extracellular compartment. The most common causes are associated with
external volume loss are:
Haemorrhage
Loss of GI fluid from vomiting, NG suction or diarrhea
Internal loss occurs when isotonic EC fluid moves into a non-functional
compartment such as tissue spaces or body cavities – the so-called Third Space
phenomena. The term non-functional is used because the fluid remains in the
body but cannot participate in the normal functions of the EC compartment.
Therefore, initial clinical outcomes are the same as those for external loss. In the
critically ill, third spacing is most often associated with conditions that cause
permeability changes in the microcirculation such as:
Burn injury
Septic Shock
Major fractures
Major surgery especially abdominal and thoracic
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
17
In these conditions, the capillaries become very leaky and allow intravascular
volume including water electrolytes, and serum proteins to escape into the
interstitium or into potential spaces such as the peritoneum and the pleural and
pericardial spaces. For example, a fractured hip is capable of sequestering up to
15 litres of fluid in the adjacent area. In most cases, this fluid will remobilize back
into the vascular space within 3 to 5 days as capillary integrity recovers. At this
time, if the patient has a limited cardiac reserve or impaired renal function volume
overload may occur. The problem with third space losses is that they are
invisible. The patient may have all the signs and symptoms of shock with no
evidence of overt volume loss. Therefore, you have to be aware of conditions
associated with third space loss and assess your patient accordingly.
Clinical Signs of Volume Deficit
Symptoms of volume deficit reflect contraction of the EC compartment. Because
there is a loss of isotonic fluid the intravascular and interstitial compartments
share the loss and intracellular volume is unchanged.
Symptoms of volume deficit will be quite familiar to you as these patients present
with the classic signs of hypovolemic shock. Cardiovascular (CVS) and central
nervous system (CNS) changes occur early with acute rapid loss. Changes in
tissue turgour may not appear until the deficit has existed for more than 24 hours.
CVS symptoms reflect depletion of circulating blood volume as well as the body’s
attempt to compensate for the deficit:
Primary
Hypotension (may be postural initially)
Decreased CVP
Flat hand veins
Prolonged capillary refill
Weak, thready pulses
Compensatory
Tachycardia to increase cardiac output
Peripheral vasoconstriction to shunt volume from non-vital organs such
as kidneys, gut and skin to vital organs such as the lung, heart and
brain
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
18
Compensatory Cont’d
Oliguria to preserve body fluid and as a result of decreased renal
perfusion
Aldosterone secretion to promote renal uptake of salt and water
ADH secretion to promote renal uptake of water
CNS symptoms reflect diminished perfusion of cerebral cells:
Initial anxiety and restlessness
Confusion
Stupor
Coma
Other organs suffer from the circulatory shunt that accompanies hypovolemia
Ileus
Oliguria progressing to renal failure
Cold, clammy extremities
Interstitial depletion is reflected primarily as changes in tissue turgour. These
changes are usually not evident until the deficit has existed for more than 24
hours and include:
Decreased turgour
Dry tongue and mucous membranes
Absence of sweating
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
19
Treatment of Volume Deficit
In the clinical setting, treatment of volume deficit is usually the number one
priority because of the stress it imposes on the heart and the systemic impact of
inadequate organ perfusion. Treatment of volume deficit is determined by the
patient’s cardiovascular and renal status, the cause of the deficit, and the nature
of the fluid that has been lost. Generally speaking, since isotonic fluid has been
lost, isotonic fluid should be replaced. Options include:
Red blood Cells
Packed red blood cells (PRBC) or whole blood is the obvious choice when
volume deficit is due to acute hemorrhage. You may also need PRBC when the
patient is having difficulty oxygenating/ventilating due to an acute loss of
haemoglobin. When infusing large amounts of PRBC, be alert for symptoms of
hypocalcemia.
Crystalloids
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
20
Since sodium is the primary ion of the EC compartment, the replacement solution
should contain sodium in relatively isotonic proportions. An isotonic salt-
containing solution will equilibrate with EC water in accordance with normal fluid
distribution i.e. 2/3 will pass in the interstitial space and 1/3 will stay in the
intravascular (IV) space. For example if 1 litre of NS is infused – 750 mL will
enter the interstitium and 250 mL will remain in the vessels. Solutions of choice
are Normal Saline and Ringers Lactate. These solutions expand the total EC
compartment; overload with crystalloid is more likely to result in tissue edema and diuresis than in circulatory overload. 5% DW is not an effective solution
treating volume deficit. This solution is hypotonic and will distribute itself
throughout the EC and the IC compartment. You’ll need a lot more 5% DW to
achieve the desired result and the patient will end up with a concentration
imbalance.
Colloids Colloid infusions consist of a balanced salt solution and protein, usually albumin.
Unlike crystalloid, these solutions remain in the intravascular space and produce
a greater intravascular expansion than the equivalent amount of crystalloid
because they draw the fluid from the interstitial space. For example 100 mL of a
25% albumin solution will increase intravascular volume by 450 mL by drawing
350 mL of fluid out of the interstitium into the vessels. Colloids are a good option
when rapid volume expansion is needed or when increased capillary permeability
is causing the deficit. Two precautions must be observed when infusing colloid
solutions:
Colloids produce a greater degree of intravascular volume expansion than
interstitial expansion. Therefore, they are likely to cause circulatory overload
in the vulnerable patient
When capillary permeability is at maximum, colloids may leak out of the
vessels into the interstitium as an osmotic gradient is established that draws
fluid out of the IV space and exacerbates IV volume depletion.
Synthetic Volume Expanders Consist of a balanced salt solution and synthetic substance such as a polymer or
polysaccharide. The most common solution of this nature is Pentaspan® Like
albumin, this solution remains in the vascular compartment. Pentaspan®
produces plasma expansion for approximately 18 - 24 hours. An IV infusion of
500 mL of Pentaspan® expands plasma volume by up to 750 mL.
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
21
The 2 main goals of therapy in volume deficit are to restore circulating blood
volume and maintain organ perfusion. 4 to 6 litres of replacement volume will be
required in patients with a moderate deficit and up to 10 litres may be needed in
severely depleted patients. All patients require close monitoring until the problem
is corrected. Watch for signs of hypervolemia that indicate that the deficit has
been overcorrected and decrease IV rate accordingly. Replacement is
considered adequate when:
Vital signs are within normal limits for that patient
Urine output is approximately _________mL/kg body wt. per hour
(average adult).
Volume Excess Hypervolemia usually occurs iatrogenically or secondary to renal insufficiency.
Iatrogenic volume excess is a frequent event in the acutely ill patient and results
from excessive administration of isotonic fluid such as Normal Saline (NS) to a
person, especially those with compromised cardiac or renal function. These
patients are also vulnerable to volume excess as third space fluid gets
remobilized back into the intravascular space. Especially vulnerable are patients
with Congestive Heart Failure (CHF) and chronic liver failure. These conditions
are characterized by progressive retention of salt and water due to over secretion
of aldosterone. Volume equilibrium is very tenuous in these patients and they can
easily get into trouble from overaggressive or inappropriate removal of and/or
additions of total body fluids.
Clinical signs of hypervolemia reflect overexpansion of the extracellular
compartment. Because there is a net gain of isotonic fluid the intravascular and
interstitial compartments share the excess therefore intracellular volume is
unchanged.
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
22
Signs of Circulatory overload predominate initially and include:
Hypertension * Full bounding Pulse
Increased CVP * Diuresis (if adequate renal function)
Distended hand veins
With adequate renal function diuresis will occur and the patient will be able to
remove the excess fluid.
Signs of interstitial overload appear later unless the excess is severe or the
patient has impaired cardiac and/or renal function:
Pulmonary edema
Peripheral edema
Overt tissue edema is a relatively late event in hypervolemia. A patient may
retain 4 – 8 litres of fluid before tissue edema is evident.
In the elderly or patients with pre-existing heart disease such as congestive heart
failure, pulmonary edema can develop quickly with only a moderate increase in
extracellular fluid volume.
Treatment of Volume excess
The goal of therapy is based on removing both fluid and salt from the body:
Simple restriction of sodium and water intake (with adequate renal
function)
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
23
If pulmonary edema is suspected, you may anticipate that diuretic therapy may
be necessary and ordered by the physician. Lasix® is a potent loop diuretic,
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
24
which will cause a salt and water diuresis but will also remove other electrolytes
from the body in the process. Potassium deficiency is a common complication of
loop diuretic therapy.
Supportive measures for treatment of hypervolemia include:
Maintain oxygenation – until pulmonary congestion is relieved as the
patient is at risk for hypoxia and will require supplemental oxygen. If
severely compromised the patient may require intubation.
Improve cardiac, renal and hepatic function – as indicated by the patient’s
clinical status
Remember high risk patients can experience hypovolemia if treatment is
overaggressive
APPENDIX A Glossary Define the following terms related to fluid and electrolytes
Acid _______________________________________________________
___________________________________________________________
Acidosis ____________________________________________________
___________________________________________________________
Active Transport _____________________________________________
___________________________________________________________
Alkalosis ___________________________________________________
___________________________________________________________
Base ______________________________________________________
___________________________________________________________
Buffer ______________________________________________________
___________________________________________________________
Capillary Hydrostatic pressure __________________________________
___________________________________________________________
Capillary Osmotic pressure _____________________________________
___________________________________________________________
Colloid _____________________________________________________
___________________________________________________________
Concentration Gradient ________________________________________
___________________________________________________________
Crystalloid __________________________________________________
___________________________________________________________
Diffusion ___________________________________________________
___________________________________________________________
Electrolytes _________________________________________________
___________________________________________________________
Evaporation _________________________________________________
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
25
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
26
___________________________________________________________
External Exchange ___________________________________________
___________________________________________________________
Facilitated Diffusion ___________________________________________
___________________________________________________________
Hypertonic __________________________________________________
___________________________________________________________
Hypotonic __________________________________________________
___________________________________________________________
Insensible loss _______________________________________________
___________________________________________________________
Internal Exchange ____________________________________________
___________________________________________________________
Isotonic ____________________________________________________
___________________________________________________________
Non-electrolyte ______________________________________________
___________________________________________________________
Osmolality __________________________________________________
___________________________________________________________
Osmosis ___________________________________________________
___________________________________________________________
Permeability ________________________________________________
___________________________________________________________
pH ________________________________________________________
___________________________________________________________
Plasma Proteins (name them) ___________________________________
___________________________________________________________
Specific Gravity (what is normal) _________________________________
___________________________________________________________
Tonicity ____________________________________________________
___________________________________________________________
REFERENCES
Astle, S. (2005), Restoring electrolytes. RN May 68(5) pg 34-39 David, K (2007) IV fluids: do you know what’s hanging and why? RN October
pages 35-40. Day, R., Paul, P., Williams, B., Smeltzer, S., and Bare, B. (2007). Brunner &
Suddarths Textbook of Medical Surgical Nursing, First Canadian Edition. Lippincott and Williams
Jarvis, C. (2009) Physical Examination & Health Assessment First Canadian
Edition; Saunders, Elsevier. Scales, K.;Pilsworth J (2008). The importance of fluid balance in clinical practice.
Nursing Standard, 22,(47), 50-57 Weldy, N. (1996) Body fluids and electrolytes a programmed presentation
seventh edition. Mosby, St. Louis Missouri. http://vchconnect.vch.ca/policies_manuals/reg_policy_clinical/clinical_care/transfusion_medicine/_docs/binary_44109.pdf
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
27
ANSWER KEY
Page 8
There are three compartments name them:
1. Intracellular
2. Intravascular
3. Interstitial
Self Check
1. Fluid inside the cell is intracellular
2. Fluid outside the cell is extracellular
3. Extracelluar fluid is divided into interstitial and intravascular
Page 11
BP: Hypotension reflects volume deficit; hypertension volume excess
Heart Rate: Will increase in response to volume deficit and may decrease
in response to volume excess
Pulse Quality: A weak, thready, obliterated pulse occurs with volume
deficit; a full bounding pulse is seen in volume excess
Assess Concentration Status: The concentration of body fluid is
determined primarily by sodium although other substances that exert an
osmotic force – especially serum glucose –may impact as well.
Concentration imbalances affect the intracellular compartment, especially
the cerebral cells:
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
28
Serum Sodium: Will be elevated in hypertonic states and decreased in
hypotonic states
VCH Acute Medical & Surgical Nursing Fluid & Electrolyte Workshop – Pre-reading Revised 2011
29
Page 13
Lab Values
Sodium (Na+) 135 – 145 mEq/L
Potassium (K+) 3.5 – 5.0 mEq/L
Calcium (Ca+) Serum 4.5 – 5.5 mEq/L Ionized 1.12 – 1.30 mEq/L
Magnesium (Mg) 0.70 – 1.10 mEq/L
Chloride (Cl-) 95 – 107 mEq/L
BUN 2.0 – 8.2
Creatinine 60 – 115 mmol/L
Hematocrit Female 36 – 46%, Male 41 – 53%
Glucose 3.9 – 11.0
Arterial Blood Gas
pH 7.35 – 7.45
PaCO² 35 – 45
PaO² 80 – 100
HCO³ 22 – 26 mmol/L (mEq/L)
What are plasma proteins?
Albumin 60 – 80 g/L
Globulin 20 – 35 g/L
Page 14
What’s my problem?
Dehydration
Renal failure