Exam 4 Flashcards
Explain the Calcium Regulation cycle if Ca2+ levels are too HIGH
Thyroid releases CALCITONIN, which:
Increases Ca2+ deposition in bones
Decreases Ca2+ uptake in intestines
Decreases Ca2+ reabsorption in kidneys
Calcium levels fall and return to homeostasis
Explain the Calcium Regulation cycle if Ca2+ levels are too LOW
Parathyroid releases PTH which:
Increases Ca2+ and phosphorus release from bones
Increases Ca2+ uptake in intestines
Increases Ca2+ reabsorption and phosphate excretion in kidneys
Ca2+ levels rise and return to homeostasis
Which type of serum calcium is biologically active and what are a few of its functions?
Free-ionized calcium is biologically active. It is essential in nerve impulse transmission, muscle and myocardial contractions, and cross-linking of fibrin threads (clot formation)
What are the causes of hypocalcemia?
Vitamin D deficiency/ impaired absorption of Vitamin D
Kidney disease (Can’t reabsorb Ca2+)
Hypoparathyroidism (not able to secrete enough PTH)
Hypoalbuminemia (low bound Ca2+ = low total Ca2+)
Hyperphosphatemia (Binds to Ca2+)
Hypomagnesemia (severe) (Mg2+ needed for PTH release)
Diuretics (cause excretion)
Chronic alcohol use ( impairs the absorption of Ca2+ in the GI tract)
What are the symptoms of hypocalcemia?
Hyperreflexia
Tetany (Chvostek/Trousseau)
Numbness & tingling in extremities and around mouth (d/t early AP threshold)
Cardiac dysrhythmias ( d/t early depolarization)
What are the nursing implications for hypocalcemia?
Increase Vit D and Ca2+ intake
Monitor post-op thyroid/ neck surgery pts for symptoms of hypocalcemia
Hold diuretics
Assess sensation, reflexes, and cardiac rhythm
Monitor Vit D, Ca2+, PO4, Mg2+, albumin (possibly PTH level)
What are the causes of hypercalcemia?
Hyperparathyroidism (secretes excess PTH)
Cancer with bone metastasis (osteolytic) and other cancers (produce factors that cause excess PTH release )
Excess Ca2+ intake and antacids (contain calcium)
What are the symptoms of hypercalcemia?
Hyporeflexia
Muscle weakness
Lethargy, confusion, cardiac dysrhythmias
Kidney stones (hypercalciuria)
What are the nursing implications for a patient with hypercalcemia?
Monitor Ca2+ level
Low Ca2+ diet
Assess mentation, reflexes, and cardiac rhythm
Maintain adequate hydration
Increase weight bearing exercises
Filter urine if needed (to catch kidney stones to be sent to the lab)
What are the functions of Phosphate?
Helps convert C6H12O6 (carbs), proteins, and fat into energy (ATP)
Essential for muscle function (because muscle needs ATP)
RBCs need phosphate to release O2 to body cells
Nervous system - produces and maintains myelin sheath
Acid-base buffering system
What are the causes of hypophosphatemia?
Inadequate intake
Malabsorption issues (chronic alcoholism, celiac disease (causes diarrhea))
Chronic diarrhea
Vitamin D deficiency
Daily use of phosphate-binding anatacids (Mg+, Al3+, Ca2+ - TUMS)
Hyperparathyroidism (increases PTH)
What are the symptoms of severe Hypophosphatemia (1.8 or lower)?
Similar to hypercalcemia sxs
Confusion
Muscle weakness
Respiratory muscle weakness
Cardiac dysrhythmias
What are the nursing implications for hypophosphatemia?
Increase vitamin D & phosphate intake
Assess neuro, respiratory and cardiac rhythm
Assess use of antacids
Monitor vitamin D, Mg+, Ca2+, and phosphate levels
What are the causes of hyperphosphatemia? (>4.5 mg/dL)
Renal failure
hypoparathyroidism
chronic use of phosphate enemas
What are the symptoms of hyperphosphatemia?
hyperreflexia
tetany (Chvostek/Trousseau signs)
numbness and tingling to extremities and around the mouth
cardiac dsythythmias
What are the nursing implications for pts with hyperphosphatemia?
Restrict food high in phosphate (dairy products)
Assess use of phosphate related meds
Assess sensation, reflexes, cardiac rhythm
Monitor calcium, phosphate, magnesium, and possibly PTH levels
They may need phosphate-binders and diuretics
How is urea nitrogen formed?
The liver produces ammonia (NH3) from protein breakdown and then converts the nitrogen to urea. Then urea travels to the kidneys to be excreted.
What do BUN levels indicate?
Liver and Kidney function
What does an elevated BUN level indicate?
increased protein intake, kidney disease, fluid volume deficit (hypovolemia/dehydration)
What does a decreased BUN level indicate?
Liver disease, low protein diet, fluid volume excess (hypervolemia)
What are the nursing implications for a patient with BUN imblances?
Assess protein levels, hydration status, assess other liver and kidney function tests (liver function panel)
What is creatinine?
A waste product from protein digestion and normal muscle breakdown. (It is proportional to the mass of skeletal muscle)
What is creatinine a sensitive indicator of?
Kidney function (it is excreted by kidneys)
What could an elevated Creatinine level indicate?
kidney damage, acute myocardial infarction, high protein intake, fluid volume deficit
What does a decreased Creatinine level indicate?
inadequate protein intake
What are the nursing implications for Creatinine imbalances?
Assess hydration, protein levels, urine output and color
What are the functions of Magnesium (Mg2+)?
transmission of nerve impulses
- muscle contraction and relaxation
needed for PTH secretion
needed to maintain K+ level via renal channels
regulation of insulin secretion by pancreatic cells
- stimulates glucose uptake from skeletal muscle
What organs regulate magnesium?
The kidneys and GI tract
What are the causes of hypomagnesemia?
chronic alcoholism
inadequate intake
Diarrhea
diuretics
What are the symptoms of hypomagnesemia?
Resemble hypocalcemia sxs, (decreased PTH will cause hypocalcemia)
increased excitability, tetany (Chvostek’s/Trousseau’s)
decreased insulin sensitivity and secretion will increase glucose levels
increased blood pressure and heart rate (low magnesium causes vasocontriction)
Cardiac dysrhythmias
What are the nursing implications for hypomagnesmia?
increase magnesium intake IV/PO
Assess labs:
- calcium, phosphate, potassium, and glucose levels
Assess vitals:
-sensation, reflexes, cardiac rate/rhythm, BP
Review medications
What are the causes of hypermagnesmia?
renal failure
IV/PO magnesium containing medications
what are the symptoms of severe hypermagnesmia?
lethargy
muscle weakness
diminished deep tendon reflexes
decreased blood pressure and heart rate
depresses heart conduction (ECG changes)
What are the nursing implications for hypermagnesmia?
Assess:
intake of Mg containing meds
kidney function
neuromuscular function
BP, HR, rhythm
possibly diuretics and IV calcium to oppose Mg
What cells secrete insulin?
pancreatic beta cells of the islet of langerhans
What are the causes of hypoglycemia?
insufficient food intake
excessive physical exertion
hypoglycemic agents
What are the symptoms of hypoglycemia?
fatigue
weakness
headache
dizziness
confusion
slurred speech
coma (if very severe)
What are the nursing implications for hypoglycemia?
assess neurological status
monitor glucose
consider dietary modifications
What are the causes of hyperglycemia?
excessive glucose intake
insulin deficiency
emotional/physical stressors
corticosteroid use (reduces the action of insulin)
parenteral therapy
What are the signs and symptoms of hyperglycemia?
polydipsia
polyuria
polyphagia
fatigue
blurry vision
infections or injuries heal more slowly than usual
What are the nursing implications for hyperglycemia?
Assess:
dietary intake
glucose
output
corticosteroid use
wound healing
What are the symptoms of low hemoglobin?
fatigue, weakness, pale skin, SOB, dizziness or lightheadedness, irregular HR, chest pain, headace
What are the nursing implications for low hemoglobin/ hematocrit?
Measure VS and monitor trends, respiratory status, surgical sites and drains
What do isotonic fluids have a similar osmolality to?
Plasma
Where do Isotonic fluids remain?
in the ECF
What do Isotonic fluids increase
intravascular volume
What are a few examples of Isotonic fluids?
0.9% Sodium Chloride (“NS”)
Lactated Ringer’s (LR)
5% Dextrose in water (D5W)* (dextrose is rapidly absorbed and becomes hypotonic
What are the indications for isotonic fluids?
resusitation (NS)
replacement to increase volume, used with other IV Txs (NS)
mild hyponatremia (NS)
hypercalcemia (except LR)
Which IV fluid is most similar to the composition of blood?
Lactated Ringer’s (aka sodium lactate)
When is Lactated Ringer’s contraindicated?
liver disease, alkalosis
When is Lactated Ringer’s indicated?
Replacement and maintenance (surgery)
What are the nursing implications for isotonic fluids?
Assess for hypervolemia:
- pulmonary edema
-hemodilution
-peripheral edema
Assess electrolytes during therapy
What are types of hypotonic fluids?
5% Dextrose in water (D5W)
0.2% Sodium Chloride (1/4 NS)
0.45% Sodium Chloride (1/2 NS)
What are the indications for hypotonic fluids?
hyernatremia, hyperosmolar hyperglycemia
Why is D5W both an isotonic solution and a hypotonic one?
It is isotonic in the bag but hypotonic once dextrose metabolizes
What is the indication for D5W?
Hypernatremia
What are the nursing implications for hypotonic fluids?
As they can increase cellular swelling monitor for cognitive changes from cerebral edema
They should be administered for a short period of time
They may cause intravascular depletion and worsen existing hypovolemia and hypotension
What are the types of hypertonic fluids?
3% NS
5% Dextrose 0.9% sodium chloride (D5NS)
5% Dextrose Lactated Ringer’s (D5LR)
tonicity is increased with added electrolytes
What are the indications for hypertonic fluids?
Severe hyponatremia (3% NS) (ICU)
Expand intravascular volume
Cerebral edema
Maintain/ replace electrolytes
What are the indications for Colloid IVF (Albumin)?
fluid volume deficit
low albumin levels
for patients who cannot tolerate large infusions (liver/ kidney disease)
What are the nursing implications for Albumin in IVF?
Monitor for fluid volume overload
Assess for pulmonary edema
Assess protein and albumin levels
When is Albumin use contraindicated?
In patients with HF
What is edema?
the accumulation of fluid in the interstitial space (aka second spacing)
What are the causes of edema?
increased venous hydrostatic pressure (IV fluids, HF)
Decreased plasma oncotic pressure (low plasma protein)
Increased interstitial oncotic pressure (accumulation of protein in interstitial space)
What are the S/sx of edema?
peripheral edema
increased BP
Polyuria
Weight gain
Crackles in lungs and dyspnea
What is third spacing?
fluid accumulates (gets trapped) in non-functional areas between cells
What are the causes of third spacing?
liver disease
Burns
Trauma
Sepsis
What are the signs and symptoms of third spacing?
hypotension
edema
decreased urine output
What is the difference between hypovolemia and dehydration?
hypovolemia - loss of water and solutes (sweating, diarrhea, trauma, burns, diuretics)
Dehydration - loss of water alone (not drinking enough water)
What are the signs and symptoms of dehydration?
Tachycardia
Orthostatic hypotension
Thirst
Dry mucous membranes
Poor skin turgor
oliguria
weight loss
What should be assessed in a patient with or suspected of dehydration?
skin turgor and mucous membranes
intake and output
urine color and quantity
urine specific gravity (>1.025)
Labs
Explain the Anti-diuretic Hormone (ADH) feedback loop
increased osmolality sensed by hypothalamic osmoreceptors and activate the release of ADH which cause:
kidneys to retain more water
decrease water loss by sweat glands
arteriole vasoconstriction
Osmolality decreases and ADH secretion decreases or stops
