Fluid and Electrolytes for Nursing Students | NCLEX RN Review (2019)

Welcome to this video tutorial on fluid & electrolyte
balance. Fluid and electrolyte balance is essential
to the process of life, and abnormal concentrations can be life threatening. In this video we will look at how fluid and
electrolyte disturbances occur, the simplified function of the electrolyte, normal values,
signs and symptoms, and basic treatment. The body is largely made up of water, or fluids,
in fact, it is approximately 50-60% of the body’s weight. Water has many important functions, including
maintenance of blood volume; cellular transport of vital substances, such as oxygen and glucose;
transport of waste products to the lungs and kidneys for removal; lubrication and cushioning;
breakdown of food in the digestive system; a medium for chemical reactions in cells;
and maintenance of body temperature. Body fluid is further broken down into intracellular
fluid (fluid inside the cell) and extracellular fluid (fluid outside the cell). All body fluid compartments contain fluids
and electrolytes. Cells maintain a balance by the transferring
of fluid and electrolytes in and out of the cell. The concentration of electrolytes depends
on the fluid volume and the body’s ability to regulate the fluid and solvents. The major intracellular electrolytes are potassium
and magnesium. The major extracellular electrolytes are sodium
and chloride. Electrolytes are ions that carry either a
positive or negative charge. Exact concentrations of electrolytes are vital
to body pH and overall homeostasis. These electrically charged ions move fluids
within the body, produce energy, contract muscles, and perform many other roles in the
body. The most prominent cations (positively charged
ions) are hydrogen, sodium, potassium, magnesium, and calcium. The anions (negatively charged ions) are chloride,
bicarbonate, sulfate, and phosphate. Most of these electrolytes come from our food
and fluid intake. Electrolytes can also be affected by medications,
hyperalimentation, blood administration, and IV fluids. (By the way for more info on types of IV fluids,
check out our video on IV Fluids: isotonic, hypotonic, and hypertonic.) Fluid and electrolyte imbalances can occur
due to various causes, such as nausea/vomiting, dehydration, surgery, trauma, burn injuries,
bleeding, and liver or kidney problems. The body’s electrolytes are regulated by the
endocrine system, the vascular system, the gastrointestinal system, and the kidneys. It’s important to know the normal ranges of
the major electrolytes, their basic functions, and the signs and symptoms of imbalances. So let’s start by looking at the reference
values you need to memorize remember that these lab values are a measurement of what
is in the ECF (extracellular fluid), it doesn’t measure the total body fluid. Also, these are guidelines, and each lab may
have a slight variation, but will also provide reference values with the test result. This list is in order from smallest to largest,
showing that the smallest quantity of electrolyte in the ECF is magnesium, compared to sodium,
which has the largest amount. Magnesium is 1.5-2.5 (it’s measured in mEq/L,
but don’t be overly concerned about remembering that it’s the number values that you want
to memorize). Phosphorus is 2.5-4.5. Potassium is 3.5-5.0, Calcium 8.5-10.5, Chloride
95-105, and Sodium is 135-145. Let’s look at each one in bold individually,
focusing on their basic function in the body, along with the signs & symptoms you will see. MAGNESIUM is a major intracellular cation
(meaning that magnesium is mostly inside the cell and just a small amount in the ECF). It’s normal range is 1.5-2.5 mEq/L. The basic
function of magnesium is muscle relaxation. So if you have a lot of magnesium, over 2.5
(called hypermagnesemia), then the muscles are too relaxed, causing muscle weakness,
vasodilation, hypotension, decreased DTR (deep tendon reflexes), respiratory arrest, and
cardiac arrest. On the other hand, if magnesium is low (called
hypomagnesemia), below 1.5, the effect is opposite muscles are excited, there’s neuromuscular
irritability, tremors, increased DTRs, tachycardia, confusion, and seizures. You often seen magnesium given in preterm
labor or preeclampsia to relax the contractions or decrease the blood pressure. You would need to assess the DTR’s during
magnesium administration, because if the magnesium level gets too high, the DTR’s will become
faint and diminish, which is a precursor to respiratory depression and cardiac arrest. POTASSIUM is also a major intracellular cation
in the body. Therefore, since the serum electrolyte value
is a measurement of the amount of potassium in the ECF, very small variances in the potassium
level make a big difference in the patient. Remember, normal level is 3.5-5.0 mEq/L. The
basic function of potassium is intracellular excitation which means it is crucial to heart
function, and can cause arrhythmias if the levels are too high or too low. Potassium also plays a role in conduction
of nerve impulses and skeletal muscle activity. Hyperkalemia is when the potassium level is
greater than 5.0 mEq/L, and can be life threatening. With a lot of potassium, there is an overexcitement
of cardiac tissue, and on the ECG you will see tall peaked T waves. You will also see muscle twitching and cramps
early on, then later, muscle weakness and paralysis, with possible life threatening
cardiac dysrhythmias. Hyperkalemia is often associated with renal
disease, because the patient is not excreting out potassium properly, but it can also be
a result of using salt substitutes and medications, such as potassium-sparing diuretics. Treatment involves renal dialysis, potassium
lowering medications, and restricting potassium containing foods. Hypokalemia is when serum potassium falls
below 3.5 mEq/L. It is usually a result of bodily fluid losses occurring from vomiting,
diarrhea, or sweating; as well as some medications such as diuretics, laxatives, or steroids. Because potassium affects the way neuromuscular
cells depolarize and repolarize energy, when potassium levels are low, the cells cannot
repolarize, are unable to fire repeatedly, causing muscles and nerves to not function
normally. Moderate hypokalemia results in muscle weakness
or spasms, leg cramping, numbness/tingling, fatigue, lightheadedness, heart palpitations,
bradycardia, and in severe cases, cardiac arrest. The ECG changes seen with hypokalemia include
a flattened T wave and possible extra U wave, because of the repolarization abnormalities. Treatment of the underlying cause and supplemental
potassium is usually given. Potassium is found in foods such as bananas,
melons, or raw spinach. Also, oral potassium supplements, IV fluids
with potassium, and switching to potassium-sparing diuretics will help increase the potassium
levels. Be sure IV potassium is diluted and administered
with an IV pump, because potassium can burn the vein and an overdose can cause cardiac
arrhythmias and death. Calcium is found primarily in the bones and
teeth (actually 99%), with the remaining 1% dissolved in the blood. The normal range for the total serum calcium
is 8.5-10.5 mg/dL, and about half of that is bound to plasma proteins, mainly albumin,
and the other half is ionized or free floating. Since albumin is made in the liver, someone
with liver problems or decreased albumin will show a low serum calcium without symptoms,
because the decrease is in the protein-bound rather than the ionized calcium. Patients who have lost ionized calcium will
be symptomatic. So let’s look at the simplified body function
of calcium neuronal excitability (or motor neurons sending signals to muscles, causing
them to contract). It’s a little confusing, because hypercalcemia
causes decreased muscle contraction, whereas hypocalcemia causes excess muscle contraction
and spasms. Think of it as a way to stabilize membrane
channels. In hypocalcemia, there are a lot of easily
excitable muscles, but calcium is not there to stabilize the membrane channels. Not enough calcium causes tetany (involuntary
contraction of muscles), vomiting & diarrhea (GI muscles are going crazy), convulsions,
and heart dysrhythmias. There are 2 classic signs of tetany that are
important to know First is Trousseau’s sign, where you inflate a blood pressure cuff above
systolic BP on the arm for 2 minutes, and the hand develops a contracted position. The other is Chvostek’s sign, which is elicited
by tapping the patient’s face lightly over the facial nerve, just below the temple, and
the result is facial muscle twitching. Treatment for hypocalcemia involves a high-calcium
diet, calcium supplements with vitamin D to enhance absorption; or for the more severe
cases with signs of tetany, an IV solution of calcium gluconate is given, along with
continuous cardiac monitoring. In hypercalcemia, there is too much calcium,
over 10.5 mg/dL. With the excess calcium stabilizing the membrane
channels, you will see decreased muscle contraction, constipation from decreased GI tract motility,
decreased DTR’s, lethargy, bone pain, and decreased activity of the cardiovascular system,
resulting in dysrhythmias and cardiac arrest. Treatment involves hydrating with fluids,
cardiac monitoring, and loop diuretics to promote calcium excretion. Sodium is the major extracellular fluid cation,
so it’s simplified body function is extracellular excitation. It has a big impact on the body’s fluid balance
and the functioning of muscles and the central nervous system. Sodium is most abundant in blood plasma, and
water follows sodium. For example, when the plasma has a high sodium
content, high levels of fluid in the plasma will occur. The normal range for sodium is 135-145 mEq/L.
Hyponatremia, or sodium level less than 135, is basically the result of having more water
than sodium. It is most commonly caused by diuretics, diarrhea,
congestive heart failure, liver disease, or renal failure. Signs & symptoms are primarily neurologic,
due to the shift of water into brain cells causing edema. These include headaches, confusion, seizures,
and coma. Other symptoms include nausea/vomiting, muscle
weakness, fatigue, restlessness, and irritability. Treatment includes correcting the underlying
cause, diuretic medications, IV sodium, and fluid restrictions. Hypernatremia, or sodium level higher than
145, results from too much sodium, not enough water. It can occur from various factors including
dehydration, fever, diabetes insipidus, Cushing’s Syndrome, long exposure to environmental heat,
or extensive exercise. Signs and symptoms of hypernatremia include
thirst, dry mucous membranes & skin, edema, agitation, restlessness, confusion, diminished
cardiac output, and in severe cases, seizures and coma. Like other electrolyte disorders, treatment
of hypernatremia includes the correction and management of underlying causes by administering
diuretics, measuring I/O, dialysis, and decreasing sodium intake. Remember, know the normal ranges and the basic
function of the primary electrolytes this will really help you in answering questions
related to fluid and electrolyte balance. Let’s look at a couple of sample questions… A nurse is caring for a patient with a calcium
level of 7.5 mg/dL. Which nursing interventions are necessary
based on this calcium level Choose all that apply. A. Assess for positive Trousseau sign
B. Implement seizure precautions C. Administer IV calcium gluconate
D. Implement continuous cardiac monitoring If you chose all of the answers, you’re correct! All of these interventions are necessary for
hypocalcemia. Here’s another one… A patient with a potassium level of 2.5 mEq/L
will exhibit the following symptoms: A. Muscle irritability, then weakness; tall
peaked T waves B. Increased DTR’s, neuromuscular irritability,
confusion C. Muscle weakness, numbness/tingling, flattened
T waves, U waves D. Relaxed muscles, vasodilation, hypotension,
decreased DTR’s If you chose C, you’re correct! Muscle weakness, numbness/tingling, flattened
T waves, and U waves, are all symptoms of hypokalemia. Great job! Thanks for watching this video tutorial on
fluid and electrolyte balance, and be sure to check out our other videos! Hope this helps you in your studies!

About the author


  1. I tried many other videos on fluid and electrolyte imbalance.. All those were difficult to understand and concentrate… This video was simple.. Very easy to understand… Helped me Alot ufreestanding Fluids and electrolytes… Thank you

  2. I gotta say, I love your video series. It's clear and straight to the point, and doesn't talk down to the viewer. Thank you! <3

  3. I love MoMetrix prep…Nurse Laura T. Is a fantastic teacher…im following these tutorials all the way to NCLEX RN!!
    Thanks Laura👍

  4. Very good that you included foods with high concentrations of certain electrolytes. NCLEX is VERY nutrition heavy! I love teaching fluids and electrolytes!

  5. Wooow…all videos are explained well with much enough content.the most common thing is the way of presentations of subjects …great job

  6. The video is very helpful and easy to understand but there is no information regarding phosphorus (hypo and hyper phosphatemia). Thank you!

  7. I love this video so much. I have watched many other videos and some are too simple and others are too deep. This is exactly what I was looking for. This is information presented in a way that I can understand it more than memorize it. Also the fact that you speak a bit like a robot and don't move, helps me focus more in the video. Also you remind me of EDI from mass effect 3. I normally don't write reviews but I really like this video. I am definitely going to subscribe and recommend. Thank you for helping nursing students.

  8. I have searched a ton of videos and listened to many lectures about F&E balance. This video is the best for me to grasp the understanding & knowledge of the patho. behind F& E. Thank you for sharing this! So helpful.

Leave a Reply

Your email address will not be published. Required fields are marked *