Hi, I'm Joanna Jackson and we're going to
review Fluid and Electrolyte Imbalances.
Many students find fluid and electrolyte imbalances
some of the most difficult content you have to learn.
Here are some tips to help you conquer this material.
Review lab values, immediately before the test begins.
Write them down on a blank piece of paper or dry
erase board that you're given as soon as the test starts.
Make up funny or quirky acronyms about medications
or processes that will help you remember them.
For example, the nursing process can be remembered
as ADPIE. Assess, diagnose, plan, implement
and evaluate. Here are some key terms. Listen for
these terms throughout this lesson, write the definition,
and practice using these words in sentences,
and visualize using them as a nurse.
First, we will talk about hypovolemia. As the name
implies, hypovolemia means volume depletion.
This volume depletion initially refers to loss
of fluid from the extracellular and eventually
the intracellular space. The clinical presentation
depends on the degree of hypovolemia. I.e. how much
fluid is lost. Initial signs and symptoms include
poor skin turgor, dry mucous membranes, tachycardia,
and decreased capillary refill. If the cause of
hypovolemia remains untreated it can lead to confusion,
agitation, hypotension and finally death. As you
can see on the slide, the most common causes
of hypovolemia include gastrointestinal losses,
excessive sweating, hemorrhage and loss of fluids
in the third space. Hypervolemia is the exact opposite
of hypovolemia. And refers to excess presence of
volume leading to expansion of the extracellular
space. It is caused by increased total body sodium
that results in increased extracellular water.
Be careful though. Although the total body sodium
is increased and this is the principle mechanism
of hypervolemia, this does not mean that there is
going to be hypernatremia. Hypernatremia refers to
the concentration of sodium. Not the amount of sodium
in the body. The majority of patients with hypervolemia
actually have hyponatremia because the water content is
greater than the sodium content. The most common
causes of hypervolemia are congestive heart failure,
liver cirrhosis, chronic kidney disease and
nephrotic syndrome. The symptoms depend
on the underlying condition. Patients with fluid
overload are most likely hypertensive and have edema.
Now, lets compare and contrast. Hypervolemia means
too much and hypovolemia mean too little body water.
Normal laboratory findings. It is really crucial and
important for your review and learn normal volumes
of each fluid and electrolyte imbalance. Again,
if you write these as soon as the test begins,
it will help you reference them when you get a question
about them. There are many different types of
electrolyte imbalances. The most common occur, in
relation to sodium, potassium, calcium, magnesium,
phosphorous and chloride. All of these have hypo
and hyper states. Let's review the most common.
Sodium is one common electrolyte that can be imbalanced
in the body.This is referred to as hyponatremia
or hypernatremia. Hyponatremia refers to low sodium
in a fluid excess. Hyponatremia refers to low sodium
in a fluid excess. Hyponatremia mainly manifests
itself with signs and symptoms from the
central nervous system such as confusion, seizures,
lethargy, and finally death. This can be caused by
GI losses, diuretics, kidney disease, sweating,
or heart failure. Hypernatremia refers to
increase sodium intake or sodium retention.
Hypernatremia most commonly occurs in elderly patients
due to diminished sense of thirst or access to fluids.
Since these patients do not drink water,
the water concentration decreases and the sodium
concentration increases. Pathologic states that
can lead to hypernatremia include hyperglycemic
states where increased glucose concentration
leads to osmotic diuresis and water loss. Diabetes
insipidus due to underproduction or diminished
action of ADH lead to excessive loss of water
from the kidneys leading to hypernatremia.
Hyponatremia is not strictly due to fluid excess.
It can mean increased, decreased or normal
extracellular fluid. I know that can be confusing,
so try and remember this by simply knowing that it
is a gain of water or a loss of sodium rich
fluids. Potassium is another major electrolyte.
This imbalance occurs in the intracellular
fluid. You have hypokalemia and hyperkalemia.
Hypokalemia refers to low potassium. Signs and
symptoms include bradycardia, nausea, vomiting
or diarrhea. This can be caused by GI losses, the
use of diuretics, kidney disease or even sweating.
Hyperkalemia refers to high potassium. The signs
and symptoms include weakness, fatigue, and arrythmias
that can potentially be life threatening. Hyperkalemia
can be caused by drugs such as ACE inhibitors and
beta blockers, chronic kidney disease,
acidosis, and Addison's disease.
What to expect on the exam? Expect questions that
give you lab values and symptoms, and ask you which
imbalance you're suspecting. Expect questions that
ask you which condition or disease is associated
with a particular imbalance. If you learn the signs,
symptoms and causes, it becomes very easy to
pick the correct treatment. Tips for success.
Always assess, diagnose, plan and then implement.
Always assess before taking any action. If two
answers feel correct, always choose the best answer.
And opposites attract, if two answers are complete
opposites, one is usually the correct answer.