Fluid And Electrolytes Flashcards
Two main fluid components of body
Extracellular— subgroups are plasma and interstitial fluids (fluid that bathes cells)
And Intracellular
How much does one liter of water weigh?
1 kg
is there more intracellular or extracellular fluid?
ICF 66%
What is main cation and anion of ECF?
Sodium + and chloride-
What are main cation and anion of ICF?
Potassium + and phosphate -
Define diffusion.
Movement of molecules from high to low until balanced.
Define active transport.
Movement of molecules from area of low to high…being pushed uphill…takes energy. Example is sodium potassium pump. Atp is the fuel
Define osmosis.
Movement of water from area of low solute to high solute. Water tries to “water down” substance. Water follows salt. Water attempts to balance
What is normal plasma osmolality value and what is its significance?
280-295 mOsm/kg milliosmoles/kg
This is an important indicator of water balance in body. Too high and it means water deficit…too low and it means water excess. This is because this is measurement of molecules to water.
What happens to a cell if bathed in a hypotonic solution? (ECF)
Water moves into cell…water is following the saltier of the two spaces
What happens to cell if bathed in ECF that is hypertonic?
Water leaves cell..shrinks…water is following the saltier of the two spaces.
What is hydrostatic pressure?
The pressure water exerts on membrane. Think pressure water exerts on inside of a water hose wall.
What is oncotic pressure, also called colloidal osmotic pressure?
Pressure the plasma colloids (proteins) exert in a solution. This draws water into vessels to water down the proteins.
What is fluid spacing?
The distribution of body water
What is first spacing?
Normal balance between ICF and ECF
What is second spacing?
Abnormal accumulation of interstitial fluid (fluid that bathes the cells) seen as edema
What is third spacing?
Excessive fluid collecting in areas that it becomes trapped…ascites, edema from burns, trauma or sepsis
What role does the hypothalamus and pituitary play in water balance?
Osmorecetors in the hypothalamus are activated by an increase in plasma osmolarity or water deficit. This is the chain that follows:
Increase salt or decrease body water….
Hypothalamus alarms….
Thirst kicks in…
Pituitary sends out ADH (vasopressin) to kidneys….
Kidneys hang onto water
This combo of increased thirst and conservation of water restores balance
What role does the hypothalamus and pituitary play in water balance?
Osmorecetors in the hypothalamus are activated by an increase in plasma osmolarity or water deficit. This is the chain that follows:
Increase salt or decrease body water….
Hypothalamus alarms….
Thirst kicks in…
Pituitary sends out ADH (vasopressin) to kidneys….
Kidneys hang onto water
This combo of increased thirst and conservation of water restores balance
What does the RAAS do?
Manages drops in BP by activating Angiotensin 2 and aldosterone to increase BP
How does Angiotensin 2 increase BP?
Vasoconstriction and increases blood volume
How does Aldosterone increase BP?
Retains Na and excretes potassium
What are the natural antagonists hormones to the RAAS system?
Natriuretic peptides made by the heart…
Atrial natriuretic hormone ANH
and B type natriuretic peptide BNP. These work to lower BP
What is normal range for serum sodium?
135-145 mEq/L
What is the major body system affected by sodium imbalances?
Neurological.
Looks like changes in mental status
Agitation, restlessness, lethargy, confusion, tremors, seizures
What is relationship of sodium and potassium?
Inverse. They balance each other. Any factor that increases sodium decreases potassium and vice versa
When rebalancing sodium in body what is the caution?
Must do it slowly with careful monitoring or could cause dangerous fluid shifts into cells.
What are some common causes of hypernatremia?
Impaired thirst cues, water loss without salt loss, too much salt ingestion or hypertonic IV solution (3% NS), Cushings syndrome (affects cortisol in body by increasing cortisol and remember too much steriod=too much sodium),
Hypernatremia s/sx.
Think big and bloated.
Late signs:
SWOLLEN DRY TONGUE
N/V
INCREASED MUSCLE TONE
Confusion
Red skin
Edema
Low grade fever
Diarrhea
Remember: Sodium affects the neuro system profoundly
What is SIADH?
Syndrome of inappropriate ADH
In this syndrome ADH is elevated—meaning water is retained and dilutes sodium. This leads to a certain type of hyponatremia called Euvolemic hyponatremia. Too much water-too little sodium.
Signs and Symptoms of hyponatremia.
Think neurological s/sx.
Depressed and deflated—–
Lethargy, confusion, agitation, restlessness, SEIZURES AND COMA, TACHYCARDIA, WEAK THREADY PULSE, RESPIRATORY ARREST, diminished reflexes, muscle spasms, abdominal cramping
Interventions for SIADH.
Fluid restrictions, Declomycin-remember no dairy or antacids with.
What are normal potassium serum levels?
3.5—-5.0 mEq/L
Anything over 7 is extremely dangerous
What are two main body systems affected by potassium imbalances?
Neurological and muscular
Causes of hyperkalemia.
Burns or any major tissue damage (destroys cells and they release K+)
Acidosis
Adrenal insufficiency (Addisons disease)
RENAL FAILURE—most common
Potassium sparing diuretics (aldactone, triamterene)
NSAIDS, ACE inhibitors
Signs and symptoms of hyperkalemia.
Think neuro/muscle..overstimulated.
Everything tight and contracted!
GI muscle will be jumpy–think cramping, diarrhea, vomiting
Confusion, irritability, fatigue, muscle weakness, increased DTRs, decreased muscle tone.
Dsyrhythmias—Tall peaked T wave, widened QRS, Loss of p wave, Bradycardia, hypotension
Nursing interventions for hyperkalemia.
Monitor cardiac, respiratory, and neurological.
Restrict potassium intake
Dialysis
Kayexalate (slow acting)
Lasix (potassium wasting diuretic)
Thiazides (potassium wasting diuretics)
Hypertonic solution of insulin and glucose (moves K+ back into cell.)
Dextrose 20% and insulin (fast acting)
Causes of hypokalemia.
Think abnormal loss from kidneys/GI tract.
Diuretics that waste potassium. (Lasix)
Corticosteroids
Cushings syndrome. (too much aldosterone)
Fluid loss (diarrhea, NG suction, vomiting)
Alkalosis
Signs and symptoms of hypokalemia.
Think low and slow in muscle and neuro.
Constipation, PARLYTIC ILIUS, weak pulse, hypotension, muscle weakness, muscle cramps, decreased DTRs, shallow respirations, EKG changes (depressed ST, PROMINENT U WAVE, flat T wave.
Interventions for hypokalemia.
Cardiac monitoring. Watch glucose levels and Na levels as these are all needed to reverse hypokalemia.
Watch magnesium levels (will also decrease in hypokalemia and if mag stays low difficult to bring K+ up)
Watch respiratory and GI systems.
Oral potassium or Potassium infusion—never give as IV push, IM or SQ. Highly irritating to veins/muscles. Give slowly in a drip. Watch for phlebitis or infiltration. Hold potassium wasting diuretics. Don’t give with digoxin.
What hormones regulate calcium levels?
Parathyroid hormone and calcitonin keep serum calcium levels in balance.
What are the two main causes of hypercalcemia?
Hyperparathyroidism
Cancer
What are signs and symptoms of hypercalcemia?
Swollen and slow and Sedating effect—reduces excitability of muscles and nerves.
Kidney stones
Increased BP
Constipation
Decreased DTRs
What are signs and symptoms of hypocalcemia?
Decreased BP
numbness, tingling in extremities and around mouth
Chvostek sign
Trousseau sign
Diarrhea
Prolonged QT intervals
Muscle spasms
Tetany
Confusion, irritability
Same as hypomagnasemia and hyperphosphatemia
laryngeal stridor
dysphagia
What is Chvostek sign?
Twitching of facial muscles when tap on cheek in front of ear. Sign of hypocalcemia
What is Trousseau sign?
Hand drawing up (carpal spasm) when BP cuff inflated
What is main cause of hypocalcemia?
Anything that would create PTH deficiency (usually surgery of parathyroid glands) or malabsorption issues that would prevent absorption of calcium.
What is normal calcium serum level?
9.0—10.5 mg/dL
What is the relationship of Calcium and phosphate?
They are inverse. Calcium up-phosphorus down and vice versa.
What does Calcium do in the body?
Bones, teeth, blood clotting, muscle and nerve function
What is a normal phosphate serum level?
3.0—4.5 mg/dL
What is the role of phosphate in body?
Building bones/teeth, muscle and nerve function. Kidneys are the regulator.
What organs regulate phosphate?
kidneys and parathyroid. Vit D is needed for phosphate absorption
Causes of low phosphate.
Antacids–cause malabsorption
Low Vit D
Hyperparathyroidism
Respiratory alkalosis
Kidneys wasting phosphate (diuretics, diabetes)
Main reason why high phosphate level.
Kidney failure
Hyperphosphatemia s/sx same as hypocalcemia s/sx. What are they?
Chvostek
Trousseau
Numbness/tingling in extremities and mouth
hyperreflexes
Muscle spasms
Tetany
Low BP
Confusion and irritability
Laryngeal spasms
Dysphagia
What is role of magnesium in body?
Muscle contraction/relaxation
Neurotransmitter release
Cardiac function
Neuro function
What two organs control mag levels in body?
Kidneys and GI system
What is normal range for mag in body?
1.3—2.1 mEq/L
Most common cause of hypermagnesemia.
Renal insufficiency
S/sx of hypermagnesemia.
Think too much control-over zealous sheriff in town.
Everything too calm and quiet.
Bradycardia, hypotension, heart block, prolonged PR intervals
Urinary retention, Decreased DTRs, muscle paralysis, hypoactive bowel sounds, respiratory depression
Causes of hypomagnesemia.
Malabsorption, Alcoholism, fluid loss
S/Sx of hypomagnesemia.
Everything is buck wild with no sheriff in town.
Increased DTR
Cardiac: V fib, tachycardia
Eyes: Nystagmus
GI: Diarrhea
Same as hypercalcemia
What are some foods high in potassium?
Beans, avocados, bananas, dried fruit, oranges, potatoes, tomatoes, nuts and seeds
What lab tests do you run for Na and K levels?
CMP, HTN panel, electrolyte panel, general health panel
What lab tests do you run for Ca levels?
BMP, CMP and renal panel
Do loop diuretics spare any electrolytes?
No they spare nothing.
Lasix (furosemide)
Bumex (bumetanide)
Edecrin (ethacrynic acid)
Demadex (torsemide)
What are some potassium sparing diuretics?
Aldactone or Carospir (spironolactone)
Inspra (eplerenone)
Dyrenium (triamterene)
Midamor (amiloride)
What are normal phosphate levels?
3.0—-4.5 mg/dL
How does the adrenal gland affect fluid balance?
The adrenal cortex releases glucocorticoids (cortisol)
and mineralocorticoids (aldosterone)
Remember—aldosterone and cortisol makes kidneys hang onto water and excrete potassium.
What is max KCl IV dose per hour?
Not to exceed 10 mEq/hr
—the exception is a critical situation but must have constant EKG monitor and must be put in central line—(remember it’s highly irritating to vein)
What is normal urine specific gravity range?
1.002——1.025
High means concentrated or dehydration
Low means diluted or over hydrated
What are some foods high in phosphate?
Dairy
Meat
Canned fish
What is the relationship and role of bicarbonate and chloride?
Inverse. The balance each other to keep acid base balance.
What is classic distinguishing sign of hyperchloridemia?
Fever
What effect does fluid loss have on Hct and BUN?
Raises.
Hct becomes more concentrated
BUN becomes more concentrated
What is average amount of insensible water loss every day?
600—-900 mL
What is ratio of hemoglobin to hematocrit roughly?
1:3
Hemoglobin 1 to Hematocrit 3
What are some hypertonic IV solutions?
D5W/0.45%NS
3% NS
D10W
Common uses for hypertonic IV solutions
Raises osmolality of ECF
Draws water out of cells
Some (D10W and D5/0.45NS) provide calories
Septic shock
What are cautions when using hypertonic IV solutions?
Can raise serum sodium too high
Can raise BP too high
What are the isotonic IV solutions?
LR
NS 0.9%
D5W
What is effect of isotonic IV solutions on body water?
Expands only ECF
Doesn’t do anything in ICF
No fluid shifts
What type of solution is D5W and what are uses?
Isotonic
No electrolytes-only water replacement
170 cal/L
Used for hypernatremia, water replacement
What are common uses of NS 0.9%?
Isotonic
Compatible with most meds
Used to prime blood tubing
Used when need to get BP up fast
What are common uses of LR?
Isotonic
Burns
GI losses
Most like plasma
–Contraindicated in hyperkalemia and lactic acidosis–
What are uses and examples of hypotonic IV solutions?
D5W
0.45% NS
Moves water from ECF into ICF
Use in DKA and severe dehydration
Use in maintenance fluids
What is difference between hypovolemia and dehydration?
Dehydration=water loss only
hypovolemia=water and electrolyte loss
What are clinical signs of hypovolemia?
Mental deterioration
Thirst
Tachycardia
Delayed cap refill
Orthostatic hypotension
Urine output of <30 mL/h
Cool, pale extremities
Increased RR
Dry mucous membranes
What are some nursing managements for hypovolemia and dehydration?
I’s/O’s
Labs:CMP, CBC, Urine Specific Gravity
Cardio:Watch BP and weak pulses
Resp: Watch for increased RR
Daily weight
Assess reflexes, muscle strength, mentation
What are some causes of hypervolemia?
Renal failure
CHF
Excessive Na ingestion
Long term steroid use
What are some nursing managements of hypervolemia?
Fluid restrictions
Daily weights
Assess for lung sounds
Assess mentation changes
Assess for skin breakdown
Diuretics
What are some clinical signs of hypervolemia?
Cardio: Bounding pulse, Increased BP
Edema
Wet lungs
Weight gain
Changes in mentation
Headache, Seizures
