Exam 4 Flashcards
Calcium function
-Regulated by calcitriol, parathyroid hormone, and calcitonin
-99% is in bone
-Combines with MG and Phosphorus for rigidity and structure
-involved in forming fibrin and in clotting
- involved in nerve transmission, muscle contraction and relaxation
Total serum Calcium = free ionized + albumin bound
Hypocalcemia
<8.5 mg/dL
-causes osteoporosis
-can cause muscle spasm and tetanus
-Chvostek’s (facial construction) and Trosseau’s (carpal spasm)
Causes of Hypocalcemia
“The hyper hippo has alcoholism so his albumin and magnesium levels are low, and has renal insufficiency”
-Hypoparathyroidism: can’t secrete PTH to increase calcium. (Neck injury)
-Hyperphosphatemia: calcium and phosphate are bound and when there are more Phosphorus ions, less free Ca+ in blood
- Renal insufficiency: can’t convert Vitamin D into Calcitriol
-Low Magnesium: Magnesium plays a role in PTH secretion
-Chronic Alcohol: promotes Ca+ excretion and prevents reabsorption by the kidneys
-Loop Diuretics: most potent/dumps everything
-Low Albumin: Calcium binds to albumin
Hypocalcemia Sx
-Hyperreflexia: Exaggerated contractions; happens bc there are more depolarizations
- Tetany (Chvostek/Trousseau)
-Numbness/tingling in extremities and around the mouth
-Cardiac dysrhythmias
Hypocalcemia Nursing Implications
-Increase Ca+ dietary sources and Vitamin D supplements
-Assess diuretic intake
-Assess post-opp thyroid or neck surgery
-Assess motion, sensation reflexes
-Assess changes in cardiac rhythm.
-Assess labs
Serum Calcium levels
8.5-10.5 mg/dL
Explain Calcium Regulation (High Levels)
When serum Calcium is too high, thyroid secretes calcitonin, which stimulates osteoblasts to remove ca from blood and deposit into bone; tells intestines to stop reabsorbing Calcium, and kidneys to stop reabsorbing calcium–> ca levels go down.
Explain Calcium Regulation (Low levels)
If serum Calcium levels are low, parathyroid secretes PTH which stimulates osteoclasts to break down bone and put into blood, and tells intestines and kidneys to reabsorb Calcium–> ca levels go up
Explain what happens to phosphorus when PTH is secreted
PTH tells the kidneys to increase calcium reabsoption and dump phosphorus, and increases the conversion of alpha hydroxylase into Vitamine D
PTH will increase phosphorus absorption in bone
The small intestine responds to increased Vitamin D levels produced by the kidney and is stimulated to reabsorb both calcium and phosphorus into blood
Hypercalcemia serum levels
> 10.5 mg/dL
Causes of hypercalcemia
-hyperparathyroidism: too much PTH being secreted
-bone cancer : all types of cancer actually. Tumor factors are secreted and stimulate osteoclastic activity
-excess intake of calcium
Hypercalcemia Symptoms
-muscle weakness
-lethargy, confusion
-cardiac dysrhythmias
-bone pain, fractures - too much osteoclatic activity
-kidney stones
“The quad-fecta + bone fractures and stones”
Hypercalcemia Nursing Implications
-low calcium diet
-fluid intake
-assess neurological functioning
-assess cardiac rhythm
-filter urine if needed
-assess labs
-bedrest
Phosphorus Levels
2.5-4.5 mg/dL
Functions of Phosphorus
-energy production from CHO, fat, and protein (ATP)
-acid-base buffering system
Hypophosphatemia
<2.5 mg/dL
Causes of hypophosphatemia
-inadequate intake/absorption issues
-chronic alcoholism
-vitamin D difficiency: can’t convert into calcitriol–> no reabsorption from GI
-overuse of phosphate binding antacids (Tums)
-hyperparathyroidism:P is Regulated by kidney: too much PTH = excessive dumping of P
Symptoms of Hypophosphatemia
-muscle weakness
-lethargy, confusion
-respiratory weakness
-cardiac dysrhythmia
similar to hypercalcemia
Hypophosphatemia Nursing Implications
-Assess neurological and respiratory function
-Assess cardiac rhythm
-Assess alcohol consumption
-Assess antacid use
-Assess for malabsorption issues
-Assess for hypercalcemia
Hyperphosphatemia levels
> 4.5 mg/dL
Causes of Hyperphosphatemia
-renal failure
-chronic use of phosphate enemas
-hypoparathyroidism
Symptoms of hyperphosphatemia
-hyperflexia
-tetany (Chvostek/Trousseau)
-numbness/tingling to extremities and around mouth
-cardiac dysrhythmia
similar to hypocalcemia
Hyperphosphatemia Nursing Implications
-Assess ROM, sensation reflexes
-Assess cardiac rhythm
-Assess kidney function
-Assess for hypocalcemia
Magnesium levels
1.8-2.2 mg/dL
Function of Magnesium
-second most abundant ICF cation
-50-60% stored in muscle and bone and 30% in cells
-Regulated by kidneys and GI
-cofactor in CHO metabolism, DNA and protein synthesis, blood glucose control, and BP regulation
-regulation of insulin secretion by pancreatic beta cells
-muscle contration/relaxation
-neurotransmitter release and neurological function
Hypomagnesemia
<1.8 mg/dL
Causes of hypomagnesemia
“C triple D”
-chronic alcoholism
-dietary intake
-diarrhea
-diuretics
Hypomagnesemia symptoms
-low MG interferes with PTH release–> same as hypocalcemia
-cardiac dysrhythmia
-Hyperglycemia
-elevated BP
Hypomagnesemia Nursing Implications
-Assess CA, K, and glucose levels
-Assess CMS
-cardiac rhythm & BP
-alcohol consumption
-GI/medical history
-review meds
Hypermagnesemia
> 2.2 mg/dL
Causes of hypermagnesemia
-renal failure
-ingestion of Mg containing medications
Hypermagnesemia symptoms (severe)
-lethargy
-muscle weakness
-diminished deep tendon reflexes
-low BP
Hypermagnesemia Nursing Implications
-ASSESS:
-intake of mg containing meds
-kidney function
-neuromuscular function
-bp
Elements in a crystallography solution
-water
-Glucose
-Electrolytes
-Vitamins
Glucose
70-110 mg/dL
-primary source of fuel
-levels fluctuate with intake and excess stored as glycogen
-insulin secreted by beta cells of islets of langerhans
Causes of Hypoglycemia
<70mg/dL
-insufficient food intake
-excessive physical exertion
-hypoglycemic agents (insulin or oral)
-alcohol: liver gets distracted from glucose regulation bc it has to detoxify body
Hypoglycemia Symptoms
-hungry
-shaky or diaphoretic
-Dizzy
-Headache
-Confusion/difficulty speaking
-weak/tired
-nervous or upset
Hypoglycemia Nursing Implications
-Assess Neurological status
-monitor glucose
-consider modifications to diet
-consider modifications to meds ( Mayne insulin dose too high or too frequent)
Hyperglycemia causes
> 110 mg/dL
-excessive CHO intake
-insulin deficiency
-empotional/physical stressors: post opp pts can develop hyperglycemia
- corticosteroids reduce effect of insulin
-parenteral therapy: some crystalloids contain dextrose
Hyperglycemia Symptoms
-sleepy
-slow wound healing
* 3 P’s:
-Polydipsia (excessive thirst)
-Polyurea (frequent urination)
-Polyphagia (hunger)
Hyperglycemia Nursing Implications
-Assessment diet
-Asses glucose levels (especially in pt with 3Ps)
-Assess output
-Assess corticosteroid use (concerned for wound healing)
-Assess parenteral therapy
-Assess wound healing (BG needs to be under 180 to facilitate wound healing)
Hemoglobin
12-18 g/dL
-is a protein combo of heme and globin
-heme carries iron; the perforin give it the red pigment
-carries 02 and CO2 back to lungs and tissues
-important for perfusion and transport of nutrients
Causes of Low levels of hemoglobin
- Anemia due to blood loss : loss of RBC and reduced ability to carry O2; possible after surgery
- Hemodilution: most common with IV fluid use “pseudo-anemia” –> RBC ratio gets diluted but no loss of RBC
Symptoms of Anemia
-fatigue/weakness
-pale
-SOB/dizzy/weakness.
-headache
-irregular HR/chestpain
Anemia Nursing Implications
-Assess for improvement of symptoms
-monitor vitals and trends
-monitor RR and O2 sat
-Assess surgical sites and drains
Hematocrit
36-50%
Volume percentage of blood that contains RBC
Hemoglobin and hematocrit have a 1:3 ratio
Low hematocrit causes
- Anemia due to blood loss
- Hemodilution
nursing Implications and SX are same as hemoglobin
Isotonic Crystalloids
-between 250 and 375 mOsm/L
-will stay in intravascular space
Examples:
- 0.9% NS
-Lactated Ringer’s
-Dextrose 5% in water “D5W”
Indications for Isotonic Crystalloids
-maintain fluid balance
-replace losses
-increase BP
-to support other IV therapies such as antibiotics
-NS can be used to treat mild hyponatremia and hypercalcemia (flushes kidneys)
Why is Lactated Ringers unique?
- it contains electrolytes and lactate
-it’s the closest to blood composition
-lactate is a base that metabolized by the liver
Do not administer to pts with Hyperkalemia, alkalosis, or pt with liver disease (lactate metabolized by liver)
Nursing Implications for isotonic crystalloids
-Assess for hypervolemia
-pulmonary edema
-hemodilution
-peripheral edema
-electrolyte labs : anytime someone is receiving IV fluids labs are drawn every morning
Hypotonic Crystalloids
<250 mOsm
Fluid will move from the intravascular space into body cells (swelling) ; left running can deplete circulatory system
Examples:
-0.45% NS
-0.2% NS
-5% dextrose (note this is also in hypotonic)
Why is D5W unique ?
-the solution itself is isotonic but after 20 mins, glucose is metabolized and it becomes hypo
-can be used for mild hypernatremia bc there isn’t Na, but monitor for normalizing values otherwise hyponatremia
Hypotonic solution Indications
-mild hypernatremia,
-hyperosmolar hyperglycemia: this is when so much glucose is in the blood cells are crenating (BG 700) need hypotonic to help rehydrate cells and dilute glucose
Hypotonic Crystalloid Nursing Implications
-monitor for changes in cognitive: cerebral edema is a concern; especially for pts with brain injury (hydrocephalus) you don’t want to administer hypo
-only administer for short periods of time
-may reduce BV intravascular space bc of fluid shifting into cells
-can worsen hypovolemia and hypotension
Hypertonic Crystalloids
> 375 mOsm
Fluid will shift from intravascular space into body cells (crenation)
-good blood volume expander
Example:
-3% NS : this one used for severe hyponatremia in ICU–>usually seizures (118-120 na level)
-10% Dextrose in water
-5% Dextrose, 0.9% NS
-5% Dextrose, Lactated Ringers
Hypertonic crystalloid indications
-severe hyponatremia (NS only)
-to expand intravascular volume
-maintain or replace electrolytes
* you would chose this over an iso if someone needed electrolytes
Hypertonic Nursing Implications
-risk of fluid volume overload
Use cautiously in cardiac and renal pt : heart and kidney help get rid of excess fluid
-administer for a short period
Colloid: Albumin
-protein that stays in intravascular space bc it can’t cross capillary membranes
- has a high affinity for water and Na and exerts “colloidal oncotic pressure” that pulls water into intravascular space
-it’s a strong (100x crystalloid) intravascular expander used for fluid volume deficit or low albumin levels
Albumin Nursing Implications
-monitor for fluid overload
-Assess urine output, protein, albumin levels
-contraindicated in heartfailure
Albumin Nursing Implications
-monitor for fluid overload
-Assess urine output, protein, albumin levels
-contraindicated in heartfailure
How are the Vitamin D cycle and calcium regulation connected?
When serum Calcium is low, parathyroid hormone is secreted. This tells the kidney that ut needs to:
1. Reabsorb calcium into blood
2. Slow reabsorption of phosphorus (P bind to Ca–>less in blood)
3. Convert calcidiol into calcitriol (Vitamin D) this is how the kidney communicates to the intestines that calcium needs to be reabsorbed; phosphorus is also reabsorbed here.
Significance of Mg
It is needed (in addition to potassium) to secrete insulin from pancreas
It also is responsible for triggering the release of parathyroid hormone
Functions of phosphorus
-85% is bound in bones and teeth
-it requires renal function
-it’s acquired from food
-primary ICF anion
