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the movement of WATER btwn two compartments separated by a semipermeable membrane.
Water moves thru the membrane from an area of of low solute concentration to an area of high solute concentration.
Water moves from the more dilute compartment (more water) to the side that is more concentrated (less water)
movement of molecules from high concentration to low.
- Stops when concentrations are equal in both areas.
- (liquids, gases, and solids)
molecules moving against the concentration gradient using ATP as it's energy.
Example of active transport
sodium moves out of the cell and potassium moving in to the cell to maintain a concentration gradient.
Oncotic pressure/Colloid osmotic pressure
osmotic pressure exerted by colloids (proteins) in a solution.
Proteins attracting water, pulling fluid from the tissue space to the vascular space.
Proteins are too large to get out of the vascular space.
ECF is made of
Consists of interstitial, intravascular and transcellular fluid
ICF is made of
Consists of fluid within the cell itself
used to describe fluids inside the body...
ie-concentration of urine and plasma
used to describ fluids outside of the body.
- normal is btwn 275-295
- above 295 =high concentration or low water content "water deficit"
below 275=little solute for the amount of water or too much water "water excess"
Solution in which the solutes are less concentrated than the cell...
Solution in which the solutes are more concentrated than the cells ....
If a cell is surrounded by hypotonic fluid, water moves....
in to the cell causing it to swell and possibly burst
If a cell is surrounded by hypertonic fluid, water moves....
out of the cell to dilute the ECF, causing the cell to shring and possible death
transfer of water and dissolved substances thru a permeable membrane from a region of high pressure to low pressure
Insensible losses are from respiration and fever. They are pure water losses and are __________ losses. Leaving the body fluids in a ___________state.
Positively charged ions
Cations-Ca, K and Na
Negatively charged ions
Anions-Cl (chloride) and HCO3 (bicarb)
General functions of electrolytes (4)
- promote neuromuscular irritability needed for proper functioning of nerves and muscles
- regulate acid/base balance
- distribute body water btwn fluid compartments
- maintain body fluid volume and osmolality
- Water moves in same proportion as body fluids
- 0.9% NS
- D5W (w is water)
- D5 1/4 NS
- D5 & 1/4 NS
- LR (Lactated Ringer)
Causes less movement of body water than body fluids do.
- 1/2 NS (0.45% sodium chloride solution)
- 1/4 NS (0.225% sodium chloride solution)
- Causes more movement of water than body fluids do
- 3% (or greater) Sodium Chloride Sol.
- 10% (or greater) D/W
- 5% D 1/2 NS
- 5% D/0.9% NS
- 5% D in Ringers Lactate Solution
Increased Osmolarity and Osmolality and Hyperosmolar =
Increased particles in the solution
Hypertonic, Decreased Osmolality and Osmolarity, and hypo-osmolar and hypotonic=
Decreased particles in the solution
How much water do the lungs remove daily through exhalation?
300mL....insensible water loss
What does ADH do?
- Antidiuretic Hormone
- Causes the body to retain water by water reabsorption
If the body senses too high of BP...what does it do?
decreases the amount of ADH released, allowing for water loss
What does the secretion of Aldosterone do?
causes sodium and water to be retained and the excretion of potassium
decrease in aldosterone causes sodium and water loss and potassium retention
What does Angiotensin II do?
stimulates the adrenal cortex to release Aldosterone
causes vasoconstriction of arterial smooth muscles.....increasing BP
Parathyroid Hormone does what?
increased PTH causes elevated serum calcium and lowered serum phosphate.
decreased PTH causes lowered serum calcium and increased serum phosphate.
Elevation of one means a decrease in the other
When plasma proteins are lowered, by colloid osmotic pressure, the fluids are shifted from the intravascular compartments in to the interstitial space. These fluids are not available for use by the body. (ascites)
How much urine should we expel in 24hrs or per hour?
- 30mL's for 2 hours....call Dr.
- minimal amount is 400-600mL/day
Fluid loss in stool, respiration and perspiration
an equal loss of fluids and electrolytes from the ECF
NO shift of fluid from intracellular space-lose sodium and water in = amounts
What causes isotonic dehydration?
- Sport/marathon runner
- NG Suctioning
losing more solutes from the ECF than water
Causing ECF to have a lower osmotic pressure than ICF so fluid shifts from ECF to ICF causing vascular swelling
What causes hypotonic dehydration?
- Anorexia/Severe malnutrition
- Chronic renal failure
- Over admin of hypotonic IV fluids (0.45 NS or D5)
a greater loss of EC Fluid than electrolytes
Causes a shift of fluid from ICF to ECF, resulting in cellular dehydration and shrinking
What are serum sodium levels in hypotonic dehydration and hypertonic dehydration?
hypotonic sodium is low
hypertonic sodium is high
What causes hypertonic dehydration?
- decreased water intake
- excess loss of water without loss of elctrolytes
- increased solute intake without sufficient water
- excess accumulation of solutes due to disease process
Example of decreased water intake that causes hypertonic dehydration
NPO for a procedure....procedure may get pushed back to NPO for all day!
Example of excess loss of water without loss of elctrolytes causing hypertonic dehydration
- watery diarrhea
- increased respiratory rate
Example of increased solute intake without sufficient water that causes hypertonic dehydration
Example of excess accumulation of solutes due to disease process causing hypertonic dehydration
S/S of deficient fluid volume
Subjective-c/o dry mouth, dysphagia, weakness, hx of vomiting, diarrhea, polyuria
- Objective-output greater than intake
- dry skin-tenting turgor
- Increased HR, RR and depth, temp, but decreased BP
- Decreased urine output
- Elevated specific gravity-above 1.0125
When you have deficient fluid volume what happens to H&H?
it will increase but you dont have more blood cells
What happens first when a person has deficient fluid volume?
decreased urine output
Where do you assess skin turgor in the elderly?
S/S of fluid volume excess:
Subjective-SOB, weight gain, fatigue, HTN, Hx of cardiac or renal disease, steroid therapy, history of use of excessive tap water enemas
S/S of fluid volume excess:
- pedal or sacral edema (+1-+4)
- Shiny taut skin
- Increased BP, bounding pulse
- Decreased urinary output
- Change in behavior-confused and lack of coordination
accumulation of fluid in all body tissues-can hear as fluid in lungs
What causes fluid volume deficienty?
What causes Isotonic fluid volume excess?
- causes ECF excess and edema
- fluid overload
- Renal failure
- Increased secretion of Aldosterone
- Steroid therapy
- inflammatory rxns
- 3rd spacing
What causes hypo-osmolar volume excess aka water intoxication?
- causes Cellular edema....
- excess intake of electrolyte free fluids-athelete drinking pure water
- Renal failure
- Sodium deficit
Interventions for fluid volume deficiency
- Control vomiting/diarrhea/reduce fever
- daily weights
- replace fluid loss as order by MD(IV or parentally)
- monitor vs
BP test to see if a pt has fluid volume deficiency....
- BP taken laying, sitting and standing with 2 min. btwn each.
+ sign is 15mmhg drop in systolic or 5 mmhg drop or +10 in diastolic
How do you treat isotonic dehydration?
replace with isotonic iV solution
How do you treat hypertonic dehydration?
replace with isotonic or hypotonic solutions (solutions that contain less electrolytes or solutes than the bloodstream)
How do you treat hypotonic dehydration?
replace with isotonic or hypertonic solutions (solutions that contain more electrolytes or solutes than the bloodstream
Interventions for fluid excess...
- Encourage pt. to decrease salt intake
- keep edematous extremity elevated above heart
- Fluid restriction as ordered
- Monitor I&O
Normal Serum Na levels
Normal serum Potassium levels
Normal serum calcium levels
S/S of hyponatremia
- delussions and hallucinations
- muscle weakness
- abdominal cramps/anorexia/NV
- Postural Hypotension
Biggest symptoms of hyponatremia are brain issues...why?
it causes brain cells to swell....cerebral edema and ICP
S/S of hypernatremia
- Dry, sticky mucous membranes
- low urinary output
- rubbery tissue turgor
- Manic excitement
S/S of hypokalemia
- apathy, confusion, coma
- muscle weakness
- abdominal distention/cramping
- shallow breathing
- CARDIAC ARRHYTHMIAS
No clinical symptoms in mild cases
- Initially-skeletal muscle spasms
- Later-muscles become weak
- cardiac arrhythmias
S/S of hypocalcemia
- muscle spasms and rigidity
- Tingly lips, nose and fingertips
- Anxiety, irritability, seizures
Where do you first notice muscle spasms for hypocalcemia?
- hands and feet
- Chvostek sign-cheek spasm
- Trousseau's sign-blood pressure cuff tightened and muscle contraction occurs at hand and wrist
S/S of hypercalcemia
- Severe thirst
- GI upset-anorexia, NV and constipation
- Respiratory weakness
- Lethargy, confusion, coma
- Bone and flank pain (kidney stones)
What causes hyponatremia?
- Potent diuretics
- GI Suctioning
- Decreased aldosterone
What should you irrigate GI tubes and body cavities with? Why?
- NS only
- Using water will deplete Na
What can you use normal water with when it comes to NG tubes?
flushing tubes, before, between and after medication administration
Disease processes that cause hyponatremia
- Renal disease
- Cirrhosis fo the liver
- Syndrome of Inappropriate Antidiuretic Hormone
- Excess secretion of ADH causing hyponatremia
If a person uses plain water enemas, or replenishes after sports with plain drinking water....what will happen?
What causes hypernatremia?
- Renal failure/Cushings
- Use of corticosteroids
- Diabetes Insipidus
- Fever, infection, excessive diaphoresis, dehydration
What will happen if a person is NPO without IV replacement and the person has no access to H2O?
How do you get hypokalemia?
- Chronic Steroid use
- Potent loop diuretics
- Loss of gastric/intestinal juices
What happens with hyperaldosteronism?
over secretion of aldosterone, which causes the kidneys to hold on to water and excret K+
How does admin of insulin cause hypokalemia?
insulin causes K+ and glucose to move in to the cell and lowers serum K+
What causes hyperkalemia?
- decreased secretion of aldosterone (adrenal insufficiency)
- Excessive admin of parenteral K+
- Respiratory acidosis
- Renal failure
- Tissue trauma
- Medication with K+ sparing diuretics
How does respiratory acidosis cause hyperkalemia?
H+ moves in to the cell and K+ moves in to the ECF
What causes hypocalcemia?
- Acute pancreatitis
- Renal failure
- Malabsorption syndromes (Crohns/Celiac)
- Diarrhea/GI wound drainage
- Lack of sunlight
What causes Hypercalcemia?
- Excessive calcium intake
- V. D intoxication
- Metastatic cancer of the bone
- Prolonged immobilization
How does acute pancreatitis cause hypocalcemia?
when pancrease is inflamed, it releases an enzyme that reacts on fatty tissue to release fatty acids...which combine with Ca+ and inactives it
How does renal failure cause hypocalcemia?
serum phosphate levels rise in renal failure...two have an inverse relationship, if phospherous rises, calcium decreases and vice versa
How does hyperparthyroidism cause hypercalcemia?
it causes excessive amounts of CA+ to be released from the bone
How does prolonged immobilization cause hypercalcemia
disuse causes increased bone resorption...CA+ moves from the bones in to the ECF
Interventions for hyponatremia
- IV 0.9% NS
- Monitor VS
- Monitor for ICP/seizure precuations
- Watch for fluid overload
- Treat whatever is causing imbalance
Interventions for hypernatremia
- Water replacement orally or D5W
- Monitor for fluid overload
- Reduce salt intake
Best interventions for hypokalemia
- K+ replacement-orally is best:
Other interventions for hypokalemia
IV...but watch for hyperkalemia and cardiac arrest!!
Eat foods rich in K+
What shouldn't the infusion rate exceed when administering Potassium?
Foods rich in K+
Interventions for hyperkalemia
- Hold K+ admin
- Kayexalate admin
- IV infusion of dextrose and insulin (if ordered)
What does Kayexalate do?
- treats hyperkalemia by:
- exchanging K+ for Na+ in the bowel, so K+ is excreted in the stool
Must retain enema for 45 minutes!!!
How does IV infusion of dextrose and insulin correct hyperkalemia?
by tricking K back in to the cell and out of the vasculature
How do you treat hypocalcemia?
- Admin of calcium-IV calcium gluconate
- admin of v. D
- Ca supplements
What do you need to watch when giving a patient calcium by IV?
When should a person take calcium supp?
Foods rich in calcium
- green leafy vegetables
Calcium has a strong effect on neuromuscular mechanisms. What nursing measures can be taken to prevent tetany and convulsions?
- decrease stimulation by:
- lights out
- speak calmly
- seizure precuations
What does long term calcium loss place a pt at high risk for?
Interventions for hypercalcemia
- hydration to prevent kidney stones
- admin of meds to inhibit CA resorption
- assess bowel activity and treat constipation
Example of drugs that inhibit calcium resorption
What are the effects of potassium imbalance on patients receiving digitalis preparations?
people taking digoxin experience increased digoxin toxicity if their serum potassium is low
Skeletal muscle weakness and paralysis may occur
What are the actions of medications used to lower serum potassium levels?
Increase elimination of potassium by diuretics
Force potassium from the ECF to the ICF by admin of IV insulin or IV sodium bicarb
Admin of IV calcium gluconate to reverse the membrance excitability (membrane potential)
What are the implications of fluid and electrolyte imbalances in the elderly client?
- physiologic changes increase their susceptability to this:
- renal fxn changes-excretion of problems
- hormonal changes-decreased/increased release
- Skin changes
- Decrease in thirst mechanism
- Musculoskeletal changes-cant hold cup
If you see a foley bag with a lot of urine....what do you assume?
the person has excreted lots of K+, if it is low....then they are holding on to K+
Describe pitting edema scale
+1 is barely perceptible...when push on skin the pit is lasting up to 5 seconds
+4 is edema when the pit lasts 20-30 seconds and is 1 inch deep
Name some food sources that are high in sodium
- salt shaker
- Processed meats
Most important NANDA for electrolyte imbalances
Risk for injury
How do you administer K-Lyte
it is an effervescent tab that must be DISSOLVED in water
Normal magnesium levels
What IV solution is compatible with most meds and blood?
Which hypertonic solutions change to hypotonic once it enters the blood stream?
- 5% D 1/2NS
- 5% D 0.9%
- 5% D in Ringers Lactate Solution
Colloid osmotic pressure does what?
Hydrostatic pressure does what?
osmolality vs. osmolarity
osmolality is concerned with weight (kg)
osmolarity is concerned with fluids (litres)
With water intoxication what are 2 key nursing interventions?
- change positions every 2 hours
- watch for SKIN BREAKDOWN, especially in edematous areas