What major complications can occur with fluid and electrolyte imbalances?
Severe fluid and electrolyte imbalances can cause life-threatening complications such as:
- respiratory depression
What main organ controls fluid and electrolyte balance?
What are the normal lab values for each electrolyte?
lab values are:
- Na: 135 - 145
- K: 3.5 - 5
- Cl: 98 - 106
- Mg: 1.6 - 2.6
- Ca: 8.5 - 10.5
- Phos: 2.6 - 4.5
It's fine if you have slightly different values memorized.
Electrolytes are important for _____ and ______ function.
Electrolytes are important for nerve and muscle function.
Electrolytes affect all the systems!
Dehydration causes which electrolyte imbalances?
Dehydration causes electrolyte levels to increase especially:
- hypernatremia and hyperkalemia
- hypercalcemia, hypermagnesemia, and hyperphosphatemia can also occur
There is hemoconcentration of the electrolytes causing the levels to look elevated.
Sodium affects which types of cells?
Sodium affects brain and muscle cells.
Sodium imbalances cause "neuro" symptoms.
What are the early symptoms of a sodium imbalance?
- neuro: headache, confusion and restlessness
- muscle: twitching and weakness
What are the late symptoms of a sodium imbalance?
- decreased level of consciousness
- ↓ respirations
- Very late symptoms: seizures and coma
Are there different symptoms for low and high sodium levels?
Low and high sodium imbalances basically have the same symptoms.
What is a characteristic symptom of hypernatremia?
Sodium has an inverse relationship with _________.
Sodium has an inverse relationship with potassium.
- ↑ sodium = ↓ potassium
- ↓ sodium = ↑ potassium
When the sodium level goes up, the potassium level goes down and vice versa.
Why does drinking too much water or receiving too much D5W (an IV fluid with a lot of water) cause hyponatremia?
Too many fluids cause the sodium level to become diluted and < 135.
What are tap water enemas and why do they cause hyponatremia?
Tap-water enemas are given in the colon to treat constipation.
Too much water can get absorbed by the colon causing hyponatremia.
What is the syndrome of inappropriate anti-diuretic hormone (SIADH) and why does it cause hyponatremia?
SIADH is a neuro and endocrine disorder that causes the body to release too much ADH.
ADH causes the body to hold onto fluids. This causes the FVO and the sodium level to become diluted and < 135.
Why does NOT drinking enough water cause hypernatremia?
NOT drinking enough water causes the sodium in the blood to become concentrated and > 145.
Why would a client not drink enough water and then get hypernatremia as a result?
Clients don't drink enough water and get hypernatremia because:
- dementia: can't remember to drink
- immobility: can't get up to get a drink of water
- elderly: older age decreases the sense of thirst
Why does too much salt intake cause hypernatremia?
Too much salt intake from diet or IV fluids makes the sodium in the blood concentrated and >145.
Why do tube feedings, when not given with additional water, cause hypernatremia?
Tube feedings have sodium in it and without water, the sodium gets concentrated and > 145.
What is diabetes insipidus (DI) and why does it cause hypernatremia?
DI is a neuro and endocrine disorder that prevents the body from making ADH.
Decreased ADH causes the body to urinate a lot. This causes FVD and the sodium level to become concentrated and >145.
Potassium affects which types of cells?
Potassium affects cardiac cells
Potassium imbalances cause dysrhythmias.
Potassium has an inverse relationship with _____.
Potassium has an inverse relationship with sodium.
↑ potassium = ↓ sodium
↓ potassium = ↑ sodium
When the potassium level goes up, the sodium level goes down and vice versa.
What are the early and late symptoms of a potassium imbalance?
- muscle issues like cramps, paresthesia or weakness
- respiratory muscle weakness and difficulty breathing
Which common cardiac medications should the potassium level be checked before giving?
Check potassium level first before giving:
- diuretics: diuretics cause the client to urinate; potassium can also be excreted
- digoxin: low potassium levels can cause digoxin toxicity
- ACE inhibitors: potassium can be increased with these meds because the client is losing sodium (↓Na = ↑K)
When potassium levels are low, it can be given as a medication to the client.
Q: How should potassium NEVER be given?
Potassium is NEVER given IV push.
The potassium can be quickly increased in the blood and the client can get a cardiac dysrhythmia and die.
~Death row inmates are given potassium IV push to stop the heart.~
Why does diarrhea and vomiting cause hypokalemia?
When there is diarrhea or vomiting the client loses potassium because potassium is in body fluids.
Why do potassium-wasting diuretics cause hypokalemia?
Potassium-wasting diuretics are a type of medication that causes the client to excrete fluids and potassium.
Why does alkalosis cause hypokalemia?
Alkalosis causes hypokalemia.
The decreased acid compensates by leaving cells and entering the blood. This puts potassium back into the cells and out of the blood.
This process lowers the serum potassium level.
What are the main causes of hyperkalemia?
Main causes of hyperkalemia:
- kidney failure: can't excrete potassium
- Addison's disease: there aren't enough steroids to hold onto sodium and water. This increases the potassium level
- too many potassium supplements
- acidosis: increased acid compensates by entering cells and releasing potassium into the blood
Why does acidosis cause hyperkalemia?
The increased acid compensates by entering cells and leaving the blood. This takes potassium out of the cell and into the blood.
This process increases the serum potassium level.
Why does Addison's disease cause hyperkalemia?
Addison's is when there aren't enough steroids to hold onto sodium and water. The client loses sodium and the inverse relationship increases the potassium level.
Why would a client take potassium supplements?
Potassium supplements are commonly taken when a client takes potassium-wasting diuretics.
Too many potassium supplements can cause hyperkalemia.
What are the interventions for hyperkalemia?
Interventions for hyperkalemia:
give glucose and insulin
- insulin drives the potassium back into the cells
- doesn't decrease K, but protects the heart from dysrhythmias
- cation exchange
What endocrine gland controls calcium balance?
The parathyroid (that is located behind the thyroid) controls calcium balance.
↑ PTH = ↑ Ca = ↓ Phosphorus
There is an inverse relationship between calcium and phosphorus.
(PTH = parathyroid hormone)
Where is calcium stored?
Calcium is stored in the bones.
Why does lactose intolerance cause hypocalcemia?
Clients with lactose intolerance can't digest lactose in dairy products, which contain calcium.
Why does Crohn's disease and diarrhea cause hypocalcemia and hypomagnesemia?
The client can't absorb calcium or magnesium because Crohn's disease is bowel inflammation where there is a loss of calcium and magnesium through diarrhea.
Why does low vitamin D cause hypocalcemia?
A client low in vitamin D would be unable to absorb calcium because vitamin D is needed to absorb calcium.
How would a client become hypocalcemic through a loss of fluids?
Calcium is excreted from the body through diarrhea and wound drainage.
Why does kidney failure generally cause hypercalcemia, hyperkalemia, and hypermagnesemia?
The damaged kidneys can NOT excrete calcium, potassium or magnesium.
Why does immobility cause hypercalcemia?
Bones that don't bear weight release calcium into the blood, causing hypercalcemia.
Why do thiazide diuretics cause hypercalcemia?
Thiazide diuretics make the client urinate but prevent the excretion of calcium.
Why does cancer cause hypercalcemia?
Cancer can invade bones and release calcium into the blood, causing hypercalcemia.
What are the complications of a consistently low and high calcium level?
- Consistently low calcium levels can cause osteoporosis.
- Consistently high calcium levels can cause kidney stones.
How can diet cause hypomagnesemia, hypokalemia, and hypocalcemia?
Certain foods contain magnesium, potassium, and calcium.
A diet that lacks in these types of foods and electrolytes can cause low electrolyte levels.
What is common between magnesium and calcium?
Magnesium and calcium both control the same nerve and muscle cells.
This causes the same signs and symptoms for Mg and Ca.
When calcium and magnesium levels are low, what are the symptoms?
↓ Ca and ↓ Mg have "high" symptoms:
- paresthesia & tetany
- ↑ deep tendon reflexes (DTRs)
- positive trousseau's and chvostek's sign
- EKG changes
- Late signs are seizures and death
When calcium and magnesium levels are high, what are the symptoms?
↑ Ca and ↑ Mg have "low" symptoms:
- ↓ deep tendon reflexes (DTRs)
- fatigue and muscle weakness
- sluggish blood flow and risk of blood clots
- Late signs are coma
Paresthesia and Tetany
Paresthesia: numbness and tingling
Tetany: muscle spasms
These symptoms are common with low calcium and low magnesium serum levels.
What are deep tendon reflexes (DTRs)?
A DTR is how the client's muscles respond to being tapped with a reflex hammer.
Abnormal findings are an indication of an electrolyte imbalance or a neuromuscular disease. Click HERE for a video showing how to test DTRs.
How are deep tendon reflexes (DTRs) graded and what does each number indicate?
- 0 = no response; always abnormal
- 1+ = a slight but present response; may or may not be normal
- 2+ = a brisk response; normal
- 3+ = a very brisk response; may or may not be normal
- 4+ = a tap elicits a repeating reflex (clonus); always abnormal
What is trousseau's sign and chvostek's sign?
Both signs occur with hypocalcemia and hypomagnesemia.
Trousseau sign: a muscle spasm caused by inflating the blood-pressure cuff to a level above systolic pressure for 3 minutes.
Chvostek's sign: twitching of the facial muscles in response to tapping over the area of the facial nerve.
Why do antacids and laxatives cause hypermagnesemia?
Antacids and laxatives contain magnesium.
Which medication is given to lower magnesium levels?
Calcium gluconate is the antidote to too much magnesium.
Why do alcoholics have hypophosphatemia?
Alcoholics have poor phosphorus intake by foods. They drink alcohol and don't eat.
How is hypophosphatemia treated?
Give phosphorus replacements.