We are into finals and the library is open 24 hours every day for the week. Why does the library need to be open 24 hours? I vaguely remember this being important in undergrad/college because a billion years ago, I did not own a personal computer until my last year at school. I sat at the library writing endless amounts of papers. Now in this school life, I can’t see why the library needs to be open all the time? In this new life of studying – there is no cramming for finals, there are no papers to write. You either know the material or you don’t. It’s weeks of knowledge built upon a semester of knowledge.
Our Pharm final is on Tuesday and I’m reviewing acid/bases. As I was rereading my notes for this lecture, here is my personal application on acid/base, fluid balance.
When I competed in my first half ironman, 70.3. Everything that could go wrong went wrong that day. First, it was an ocean swim and I had never practiced that distance (1.2 mile swim) in an ocean. I ended up having a terrible time sighting the shore line because of the sun, and I swallowed horrible amounts of salt water, making me feel nausea when exiting the swim. When exchanging empty water bottles for full water bottles on the 56 mile bike course, I failed to practice drinking the course provided fluid mix and was repulsed by the flavor. It made me want to vomit and I ended up only drinking water. By the run course, the mid day heat had started, and I sweated excessively while only drinking water. I wanted to finish the race because if I went to a medical station while on the course I would be stamped with a DNF (did not finish). I figured if I passed out on the course, someone would scoop me up, so I finished the 13.1 run and then went to the medical tent to get IV fluids. What went wrong – here’s the real life application:
Normally – your cells are isotonic – same amount of intracellular fluid = extracellular fluid, solute to water concentration are the same on both sides of the cell. In my race, I had a loss of salt from sweat, and taking in too much water without other solutes to balance my water-fluid concentration, which is called hyponatremia. HYPOTONIC (more solutes inside the cell, water follows solutes inside the cell, and your cells SWELL). Water moves from extracellular to intracellular and your fingers/feet swell. Serious complications, left untreated can result in coma, seizures, respiratory arrest. Sodium levels are less than 135 mEq/L. Admin: (I think is a hypotonic solution of D5W.)
Next application example: When I biked the U.S., there was one very hot day in the Ozarks (Missouri). I had 20 miles left in our day, and I had drunk all my water. I felt dizzy and looked for a shady patch to stop. I looked up in the tress, and instead of seeing leaves swaying in the wind, I saw people dancing. Upon closer inspection, there were not people dancing in the trees, but there were leaves. Clearly, I was on my way to having heat stroke, but some how compelled myself to finish, arrive at camp and replenish my fluids and take a cool shower. If I did go to the hospital, I think I would have received a (hypertonic) solution of D5 1/2 NS D5NS for fluid replacement. A nurse would have monitored my BP, pulse rate and quality of lung sounds, as well as NA and urine output.
The opposite of hyponatremia is HYPERnatremia. It is inadequate water, excessive water excretion usually from dehydration, heat stroke, or too much sodium (kidney failure). Sodium is greater than 145 mEq/L. Cells are HYPERTONIC – more solutes are outside than inside the cell, water follows solutes outside of the cell, cell shrinks. Left untreated can result in significant neurological, endocrine, and cardiac problems.
If you have trouble remembering hypotonic vs. hypertonic. Hypo sounds like hippo – and I think of Fiona, the hippo at the Cincinnati zoo. She’s made recent headlines. She’s growing and is huge, therefore SWELL. And, hyper is just the opposite.
I don’t have any personal application for the other solutes we have to remember so here they are:
When dissolved in water, electrolytes separate into ions and then conduct either a positive (cations: magnesium, potassium, sodium, calcium) or negative (anions: phosphate, sulfate, chloride, bicarbonate) electrical current.
Na – major extracellular fluid cation, regulates osmotic forces and water balance, regulates acid-base fluid balance (buffer), facilitates nerve conduction and neuro-muscular function, active and passive transport across cellular membrane. Sodium levels 135-145 mEq/L.
Potassium – K (3.5-5 mEq/L) – major intracellular fluid cation, maintains cell electrical neutrality, facilitates neuromuscular transmission of nerve impulses; vital role in cell metabolism; functioning of cardiac, lung, muscle tissues, acid-base balance (leg cramps). Reciprocal action with sodium.
HYPOkalemia –potassium less than 3.5 mEq/L. Result of increased loss of K (avocados, dried fruit, cantaloupe, bananas, potatoes, spinach).
HYPERkalemia – potassium greater than 5.0 mEq/L. results of inadequate renal excretion (kidney function), life-threatening – risk of cardiac arrhythmia/cardiac arrest.
-potential, ECF shift – insufficient insulin/acidosis (diabetic), trauma/surgery, fever, uncontrolled diabetes
Magnesium – Mg (1.5-2.5 mEq/L) – smooth muscle contraction (whole grains, dark vegs)
HYPOmagnesemia – less than 1.5, (malnutrition, alcohol use disorder, laxative use) – increased nerve impulse
HYPERmagnesemia – higher – chronic kidney disease.
Calcium – Ca (4.5-5.5 mEq/L) – cell permeability, bone and teeth formation, cardiac action potential, muscle contraction, blood clotting.
HYPOcalcemia – less than 4.5 mEq/L – Crohn’s disease (malabsorption), Vitamin D deficiency (alcohol use disorder, chronic kidney disease)
HYPERcalcemia – too much – bone cancer…
Here are some questions for you to answer after reading:
- What are examples of isotonic, hypertonic, and hypotonic iv fluids that a nurse would administer? What would be important to monitor when administering a hypertonic solution?
- What are the major cations and ions located in the intracellular and extracellular fluids?
- What is the normal range and role of the following electrolytes: sodium, potassium, calcium, and magnesium?
- What happens to cells when they are placed in isotonic, hypertonic, hypotonic extracellular fluids?
- What does isotonic, hypertonic, and hypotonic mean?