Electrolyte balance Flashcards
electrolytes to focus on:
NA, K, CA, MG, P, CL
electrolytes in body fluids functions, diff of osmolarity/osmolality
- Electrolytes function as a group
- To promote neuromuscular irritability (how muscles move, how body functions)
- Maintain body fluid volume and osmolality
- Osmolality is the measure of the concentrating ability of the kidney (measure of fluid; solvent)
- Osmolarity is the concentration of particles in the blood. An indication of hydration (275-295 mOsm/kg) (measure of particles; solutes)
- help distribute body water between fluid compartments
- regulate acid-base balance
electrolytes
- Solutes are substances that are dissolved in body fluids
- Nonelectrolytes
- Do not separate into charged particles
- Example: glucose
- Electrolytes
- Do separate into charged particle
- Cations (+)
- Anions (-)
- Normally total number of+/- charges are equal on both sides of cell, not necessarily the same electrolytes, but the same charge.
- Do separate into charged particle
- Nonelectrolytes
regulation mechanisms for electrolytes
Thirst
Kidneys: Volume and osmolality
RAA Mechanism:
-Responds to hypotension
-Vasoconstriction
-Na+ regulation
-ADH
-osmolality
-blood volume
-aldosteroneinside the cell is mostly what electrolyte? outside? their charges?
inside: mostly K
outside: mostly Na
both have pos charge. big big influencers on charge inside/outside cell
lost electrolytes thru?
-Losses that override bodys homeostatic abilities, theres a problem. losses happen via •GI tract •Urinary tract •Sweat •Vomit •Nasogastric suctions •Wound drainage, hemorrhage
sodium functions
- maintain ECF volume
- regulate acid base balance with ions
- conduct nerve impulses
sodium normal
135-145 meq/L
what regulates sodium
aldosterone, ADH, ANP
hypernatremia pt teaching
look in book for pt teaching and tx
hypernatremia definition, causes
> 145.
more water is lost than sodium.
causes: cushings syndrome, diabetes insipidus.
hypernatremia leads to?
cellular dehydration
hypernatremia s/s
thirst low grade fever peripheral/pulmonary edema postural hypotension AMS neuromuscular irritability coma/seizures
hypernatremia tx
oral water replacement
cerebral edema risk if water replacement given too fast
hyponatremia, causes, effect on cells
(Low Serum Sodium)
• Water retention, loss or inadequate intake of sodium
• Diuretics
• Vomiting, diarrhea, GI suctioning
• Wound fluid loss
• Overuse of certain IV fluids ( too much 1/2 NS –> hyponatremic blood )
• Cells have reduced ability to depolarize
hyponatremia s/s
- lethargy
- headache
- confusion
- personality changes
- apprehension
- seizure, coma
- brain damage is possible(SIADH)
what electrolyte has the most impt role for tonicity, fluid shifts
Sodium has THE most impt role with tonicity, fluid shifts when it comes to composition of blood/interstitial fluid/cells if we could measure them
hyponatremia tx
restrict water
intake sodium
oral unless very severe (risks with IV)
treat the underlying cause
potassium functions, normal
normal: 3.5-5.5 (narrow therapeutic range)
- intracellular osmolality
- cellular depolarization and repolarization
- cellular integrity
- neuromuscular impulses
- acid base balance
- carbs into energy
- amino acids into proteins
- cardiac contractions (the biggest concern!)
why is potassium important for the body
Also plays bigbig role because there’s lot of potassium in cell and also because it has huge impact on cardiac function: we worry if K is outisde normal, high or low, either one puts pt at risk for fatal dysrhythmia. It also has very narrow therapeutic range: 3.5-5.5 per the book
hyperkalemia causes
> 5.5
- increased K intake
- decreased urinary excretion
- cellular damage, trauma (crush injuries and such) (Most common electrolyte in the cell: enough cells die from injury and insides of cell leak into bloodstream –> hyperkalemia)
- inappropriate iv fluids
- renal failure
- potassium sparing diuretics
- severe acidosis
- sepsis
- decrease in aldosterone, insulin
- addison’s disease
hyperkalemia s/s
- irregular pulse
- irritability
- ABD distension
- cramping
- muscle weakness (sometimes the first sign)
- paresthesia, numbness
- diarrhea
- EKG changes
hyperkalemia ekg changes
The first change we will see with hyperkalemia is peaked T waves, but if it gets bad enough then it becomes a fatal dysrhythmia (severe hyperkalemia)
hyperkalemia tx
-treat underlying cause
-reduce K intake
-potassium reducing agents
In order from mild to severe tx:
1. loop diuretics (lasix PO) for potassium loss
2. kayexalate PO. Helps K exit body. Exits thru severe diarrhea. But better than having too much potassium. Let pt know, bathroom access.
3. calcium plus glucose (D50) plus insulin: IV calcium, glucose, and insulin. This draws K out of bloodstream because insulin helps open the door so glucose goes in, and K at same time comes out. Stays out. Decreases level very fast. However, it’s still in body unlike Kayexalate (also give them a loop diuretic) so it’ll very slowly go back into blood.
4. dialysis (very bad hyperkalemia)
hypokalemia, causes
serum potassium <3.5
- certain diuretics
- hypomagnesemia
- GI/renal disorders
- cushing’s disease
- elevated insulin
- vomiting, diarrhea, nasogastric suction
hypokalemia s/s
- muscle weakness, cramps
- n/v
- paresthesias
- weak, irregular pulse
- ekg changes
hypokalemia ekg changes
atrial and ventricular flat T’s
presence of U waves
hypokalemia tx
- treat underlying cause
- foods high in potassium (it’d actually take like 10 bananas/day to equal the minimum dose of potassium, 10meq)
- IV only if life-threatening (IV k: Don’t wanna run it any faster than 20meq/hr. Running pure K is very painful, causes site burning (assure pt the IV is fine, the K is just irritating to lining of veins. can ice the site to make the pain better, or slow it down, but better to ice it so pt is not in pain for longer)
- PO potassium. Don’t wanna give more than 20meq PO at a time, sometimes will see orders for 40, but body won’t absorb it as well at that dose. Usually 20, 4 times a day.
calcium functions, normal range
normal: 9-11 helps with: -neuromuscular transmission -muscle contraction -blood clotting -bones and teeth -cellular membranes -energy conversions
regulation mechanisms for calcium
- Vitamin D
- calcitonin
- parathyroid hormone (One of the biggest diseases affecting Ca is a main pathology)
hypercalcemia causes
- primary hyperparathyroidism
- bone malignancy
- drug toxicity
- other less common causes
hypercalcemia s/s
bone weakness
bone demineralization
cardiac irregularities
hypercalcemia tx
underlying cause
acute severe cases: furosemide
Drugs: bisphosphonates, glucocorticoids, calcitonin
hypocalcemia causes
- decreased PTH
- elevated phosphorus
- decreased mg
- hypoalbuminemia
- alkalosis
- Vit D deficiency
- renal failure
- pancreatitis
hypocalcemia s/s
- dysrhythmia, bradycardia, hypotension
- numbness of hands, hyperactive reflexes around mouth, bronchioles
- confusion, hallucinations, anxiety, depression, psychosis
- seizure
hypocalcemia tx
oral/IV calcium
monitor phosphorus, Vitamin D
risk for cardiac arrest, hypotension
magnesium functions, normal
enzymatic activities, neuromuscular interactions, neurotransmission, cardiac contraction, energy conversion, carbohydrate metabolism, protein synthesis
Normal: 1.8-3.0
hypermagnesemia causes
Renal failure, adrenal insufficiency, IV Mg in obstetrical setting, DKA
hypermagnesemia s/s
- Hypotension, bradycardia, respiratory or cardiac arrest.
- N/V
- mental changes, respiratory depression, decreased deep tendon reflex
hypermagnesemia tx
Treat underlying cause
Avoid Mg
Iv administration of supplements to decrease absorption, dialysis, diuretics
hypomagnesemia causes
Alcoholism Diabetes Loop diuretics Malnutrition Vomiting, diarrhea Malabsorption syndromes
hypomagnesemia s/s
severe deficiency:
- Confusion, lethargy, seizures, tetany, deep tendon hyperreflexia, hallucinations
- N/V
- HTN, dysrhythmia (ST depression, prolonged QT, SVT)
- death possibly
hypomagnesemia tx
oral treatment
IV if severe and acute
phosphorus functions, normal
- carbohydrate, lipid, and protein metabolism
- nerve/ muscle function
- part of basic energy units
- cellular and organelle membranes
- RBCs
Normal: 2.5-4.5
phosphorus regulators
calcitonin, PTH, vitamin D
hyperphosphatemia causes
Renal disease, decreased excretion, excessive replacement, overuse of phosphate based enemas, acidosis, cellular destruction
hyperphosphatemia s/s
deposition of calcium phosphate in soft tissues, dysrhythmias, occurs w/ hypocalcemia
hyperphosphatemia tx
Phosphorus binding antacids
calcium based antacids
hypophosphatemia causes
Vitamin D deficiency, bowel disorders, phosphate bind antacids, alcoholism, diabetic ketoacidosis, resp alkalosis
hypophosphatemia s/s
- Confusion, apathy, delirium, hallucinations
- coma, seizure
- peripheral neuropathy
- ascending motor paralysis
- dysrhythmias, hypoxia, heart block
- resp failure
chloride functions, normal
Chloride:
Electrical neutrality, Na reabsorption, hydrochloric acid for digestion, bicarbonate.
its main thing is acid-base balance.
Normal: 97-107
hypophosphatemia tx
Treat underlying cause
High phosphate diet
Avoid phosphate binding antacids
IV for severe cases or bowel dysfunction
hyperchloremia causes
Acidosis, hyperparathyroidism, dehydration, resp alkalosis
hyperchloremia s/s
Increased depth and rate of respiration, lethargy, stupor, disorientation, coma
hyperchloremia tx
look in book
hypochloremia causes
Loss of GI fluid (vomiting, duodenal ulcer), DKA, bartter’s syndrome
hypochloremia tx
look in book
hypochloremia s/s
Hypochloremic alkalosis, paresthesia of face and extremities, muscle spasms and tetany, slow shallow respirations, dehydration
main thing about chloride, what to suspect or look at when its abnormal
its main thing is acid-base balance. so it’s always hardest lab to address when abnormal. it’s usually very minorly out of range; look at things like dehydration, Parathyroid. mainly think about hydration status for abnormal chloride.
