Ch. 13 Flashcards
dehydration means that there is a lack of ___ in the body
- fluid intake is less than what is needed to meet the body’s fluid needs
- no water or no salt or both
causes of dehydration
- inadequate fluid intake
- loss of sodium in diet (ie maybe they completely cut out sodium from diet)
- loss of fluid and electrolytes (ie. vomiting and diarrhea, or diabetes insipidus, excessive sweating)
- excessive caffeine intake, alcohol intake
- fever of 102/103- diaphoretic
- medication: diuretics
adverse effects of dehydration: 0% body weight loss
thirst
adverse effects of dehydration: 2% body weight loss
- stronger thirst
- vague discomfort
- loss of appetite
adverse effects of dehydration: 3% body weight loss
- decreasing blood volume
- impaired physical performance
adverse effects of dehydration: 4% body weight loss
- increased effort for physical work
- nausea
adverse effects of dehydration: 5% body weight loss
- difficulty concentrating
adverse effects of dehydration: 6% body weight loss
- failure to regulate excess temperature
adverse effects of dehydration: 8% body weight loss
- dizziness
- labored breathing with exercise
- increased weakness
adverse effects of dehydration dehydration: 10% body weight loss
- muscle spasms
- delirium
- wakefulness
adverse effects of dehydration: 11% body weight loss
- inability of decreased blood volume to circulate normally
- failing renal function
clinical manifestations of dehydration
- cardiovascular changes: decreased plasma volume, increased HR, low BP
- respiratory changes: increased RR
- skin changes: dry, moist (fever)
- neurologic changes: confusion, lethargic
- renal changes: decreased urinary output, dark/concentrated urine
laboratory assessments of dehydration
elevated:
- hemoglobin
- hematocrit
- serum osmolarity
- glucose
- BUN
- electrolytes
hemoconcentration causes the blood to be very concentrated and elevate these levels
*assess in correlation with physical findings, labs on their own don’t conclude dehydration
analysis/patient problems of dehydration
- poor perfusion due to excess fluid loss or inadequate fluid intake
- potential for injury due to blood pressure changes and muscle weakness
dehydration: nurse management
- safety
- strict I&O**
- monitor labs
- monitor cardiovascular/ respiratory status
- daily weights**
- skin care, oral care (very dry- make sure that they are moist/clean)
- monitor for complications
1L of water is ____ lb of water, which is __ kg
2.2 lbs, 1 kg
weight change of 1 lb = fluid volume change of ___ mL
500 mL
fluid overload
- excess of body fluid
- hypervolemia
dilution of sodium and potassium can lead to ___
- seizures
- coma
- death
severe fluid overload can lead to ___
- heart failure
- pulmonary edema (RRT needed)
hyponatremia
- sodium level below 136mEq/L
(more common than hyper)
causes of hyponatremia
- increased sodium loss
- excess water- dilutional (kidneys are not working well)
- dehydration* most likely cause
- liver disease
- adrenal insufficiency
clinical manifestations of hyponatremia
- sodium loss vs fluid gain
- *neurologic: lethargic, seizures, confusion
- CV: low BP, high HR
- skin: dry, decreased skin turgor
- GI: nausea, diarrhea
*affects neuro the most
hyponatremia interventions
- treat underlying cause
- sodium replacement
- monitor
hyponatreamia interventions: sodium replacement
- IV (hypertonic) (0.9% NS)
- diet (foods with sodium)
- medications (mannitol if dilutional)
hyponatremia interventions: monitor for
- I/O
- urine specific gravity
- BP, CV, respiratory status
- neurologic status
- daily weights
- edema (effect from the treatment- fluid volume overload)
hypernatremia
- serum sodium level over 145 mEq/L
causes of hypernatremia
- dehydration
- excessive sodium intake (high sodium diet)* most likely cause
- regulatory abnormalities
- hypercortisolism
- kidney disease
clinical manifesations of hypernatremia
- neurologic
- renal: underlying kidney disease
- cardiovascular: elevated BP
- respiratory (if caused by dehydration)
- integumentary (if caused by dehydration)
hypernatremia interventions
- safety (seizure monitoring)
- medication: diuretic (lasix)
- IV therapy: sodium free fluids initially
- diet: low sodium diet, fluids if dehydrated
- monitor: VS, I&O, daily weights, edema
*depends on cause (water loss or sodium gain)
hypernatremia interventions: diet
- fluids if dehydrated
- low sodium diet
hypernatremia interventions: monitor for
- VS
- I/O
- daily weights
- edema
hypokalemia
serum potassium level below 3.5mEq/L
*can be life threatening because every body system is affected
causes of hypokalemia
- abnormal losses: diuretics, GI losses (vomiting, NG tube, diarrhea)
- other conditions: metabolic and respiratory alkalosis
- fluid overload
- insulin administration
- hyperaldoseteronism
clinical manifestations of hypokalemia
- cardiovascular: irregular beat and rhythm- should be on heart monitor
- metabolic: muscle weakness, falls
hypokalemia interventions
- safety
- potassium replacement (PO or IV)
- educations: diet (citrus, banana), diuretic use (electrolyte checks)
potassium replacement IV should not be faster than _____
10 mEq/hr **NO FASTER
can potassium replacement be given as IV push?
no- never
- can cause cardiac arrest –> heart stops –> kill patient
hyperkalemia
serum potassium greater than 5.0 mEq/L
what is the most severe problem that results from hyperkalemia?
cardiovascular changes
- also the most common cause of death in patients with hyperkalemia
causes of hyperkalemia
- dehydration
- kidney disease
- acidosis
- adrenal insufficiency
- crush injuries
- medication (potassium-sparing diuretic: spironolactone, ACE-Inhibitors)
- blood transfusion
clinical manifestations of hyperkalemia
- cardiovascular
- neurologic: muscle weakness
- GI: diarrhea
hyperkalemia interventions
- safety
- drug therapy
- monitoring
- health teaching
drug therapy for hyperkalemia
- sodium polystyrene (drink- causes patient to have a BM, gets rid of potassium through BM)
- IV insulin (pulls potassium from blood stream back into cell) and glucose (balancing out the blood sugar)
hyperkalemia interventions: monitoring
- cardiac - life threatening
- neurologic
hyperkalemia interventions: health teaching
- diet (no citrus, low sodium diet)
- avoid salt substitutes
- increase fluid intake (helps dilute potassium)
hypocalcemia
total serum calcium level below 9.0 mg/dL
causes of hypocalcemia
- dietary intake
- inadequate absorption
- increased phosphorus
- decreased PTH
- vit D deficiency
- hypothyroidism
- hypoparathyroidism
- kidney disease
- excessive intake of phosphorus-containing foods and drinks
clinical manifestations of hypocalcemia
- neurologic (tingling/numbness)
- cardiovascular changes (bradycardia, EKG changes)
- intestinal changes (cramping)
- skeletal changes (charlie horse, tingling in muscle)
chvostek’s sign: decrease calcium in the blood results in facial twitching when the facial nerve is tapped
hypocalcemia inteventions
- drug therapy (Vit D)
- nutritional therapy (encourage foods high in calcium: yogurt, milk)
- environmental management (potentially, seizure precautions)
- injury prevention strategies (taking vitamins to prevent bone fractures
hypercalcemia
total serum calcium level above 10.5 mEq/L
causes of hypercalcemia
- hyperparathyroidism
- increased CA or Vit D
- malignancy
- prolonged immobilization
- hyperthyroidism
clinical manifestations of hypercalcemia
- effects of hypercalcemia occur first in excitable tissues
- cardiovascular (most important)
- GI
- renal
hypercalcemia interventions
- drug therapy
- dialysis
- cardiac monitoring
hypercalcemia interventions: drug therapy
- IV 0.9% sodium chloride
- furosemide
- calcium chelators
agents that prevent hypercalcemia
- phosphorus
- calcitonin
- biphosphonates
- prostaglandin synthesis inhibitors
hypophosphatemia
serum phosphorous level below 3 mEq/L
hyperphosphatemia
serum phosphorous level above 4.5 mEq/L
what two ions exist in the blood in a balanced reciprocal relationship?
- calcium and phosphorous
assessment of hypophosphatemia
- low phosphorus , high calcium
assessment of hyperphosphatemia
- high phosphorus, low calcium
management of hypophosphatemia
think high calcium (hypercalcemia interventions)
- drug therapy (IV 0.9% NS, furosemide, calcium chelators
- dialysis
- cardiac monitoring
management of hyperphosphatemia
- drug therapy (Vit D)
- nutritional therapy (encourage foods high in calcium: yogurt, milk)
- environmental management (potentially, seizure precautions)
- injury prevention strategies (taking vitamins to prevent bone fractures
hypomagnesemia
serum magnesium level below 1.3 mEq/L
effects of hypomagnesemia are caused by
- increased membrane excitability
- accompanying serum calcium and potassium imbalances
- malnutrition
- alcoholism
- ketoacidosis
clinical manifestations of hypomagnesemia
- neuromuscular changes
- CNS changes
interventions for hypomagnesemia
- drugs: IV mag sulfate
hypermagnesemia
serum magnesium level above 2.6 mEq/L
when magnesium excess occurs, excitable membranes are ___
less excitable
- need a stronger than normal stimulus to respond
clinical manifestations of hypermagnesemia
- cardiac changes
- CNS changes
- neuromuscular changes
- respiratory changes
hypermagnesemia interventions
- magnesium-free IV fluids
- furosemide
- calcium
percentage of the body composed of fluid
> 50%
body fluids deliver _____ to all tissues and cells in the body
nutrients and electrolytes
two main compartments of body fluids
- ECF
- ICF
three processes that control fluid and electrolyte balance
- filtration
- diffusion
- osmosis
filtration
movement of fluid through cell or blood vessel membrane because of differences in water pressure (hydrostatic pressure)
- water volume pressing against confining walls
diffusion
free movement of particles (solute) across permeable membrane from area of HIGHER to LOWER concentration
osmosis
movement of water only through a semipermeable membrane to achieve an equilibrium of osmolarity from area of LOWER concentration to HIGHER concentration
clinical example of filtration
blood pressure
hydrostatic pressure is
“water pushing pressure”
- force that pushes water outward from a confined space through a membrane
what determines the amount of pressure? (re: hydrostatic pressure)
the amount of water in any body fluid space
example of hydrostatic pressure
blood pressure
- moving whole blood from the heart to capillaries where filtration occurs to exchange water, nutrients, and waste products between the blood and tissues
this process is important in the transport of most electrolytes
diffusion
other particles diffuse through ____
cell membranes
clinical example of diffusion
- transport of most electrolytes and other particles through cell membrane
- sodium pumps
glucose cannot enter most cell membranes without help of ___
insulin
osmolarity
number of milliosmoles in a liter of solution
osmolality
number of milliosmoles in a kilogram of solution
1L of H2O = __ kg
1 kg
normal osmolarity for bodily fluids:
270-300 mOsm/L
osmosis and filtration work together to ___
act at capillary membrane to maintain normal ECF and ICF volumes
example of how osmosis helps maintain homeostasis:
thirst mechanism
the feeling of thirst is caused by ___
activation of brain cells responding to changes in the ECF osmolarity
fluid types
- isosmotic or isotonic (normotonic)
- hyperosmotic or hypertonic-osmolarity
- hypo-osmotic or hypotonic-osmolarity
isosmotic or isotonic (normotonic): osmolarity
270-300
hyperosmotic or hypertonic-osmolarity: osmolarity
> 300
hypo-osmotic or hypotonic-osmolarity: osmolarity
< 270
fluids are regulated through the
thirst drive
fluids enter the body mostly as
liquids
adults need ___ (amount) of water per 1000kcal
1000mL per 1000kcal
fluids loss occurs through
several routes
- sweating
- urine
minimum amount of urine needed to excrete toxic waste products is ___
400-600mL
insensible water loss is (amount)
500-1000mL
what 3 hormones control fluid and electrolyte balance
- aldosterone
- antidiuretic hormone (ADH)
- Natriuretic peptides
what are the most important fluids to keep in balance?
- blood (plasma) volume
- intracellular fluid
what organ is the major regulator of water and sodium?
the kidneys
the kidneys maintain ____ and ___ to all tissues/organs
- blood pressure and perfusion to all tissues/organs
what do the kidneys secrete when they sense a low parameter?
renin
RAAS (renin-angiotensin-aldosterone system) is greatly stimulated when ____
- when in shock
- when stress response is stimulated
electrolyte imbalance can occur in healthy people as a result of
changes in fluid intake and output
electrolyte imbalance includes:
- sodium
- potassium
- calcium
- magnesium
causes of hypermagnesemia
- kidney disease
- hypoparathyroidism
- adrenal insufficiency
causes of hypochloremia
- fluid overload
- excessive vomiting or diarrhea
- adrenal insufficiency
- diuretic therapy
causes of hyperchloremia
- metablic acidosis
- respiratory alkalosis
- hypercortisolism
causes of hypo-osmolarity
- fluid overload
- hyponatremia
- hypoproteinemia
- malnutrition
causes of hyperosmolarity
- dehydration
- hypernatremia
- hyperglycemia
normal sodium range
136-145 mEq/L
normal potassium range
3.5-5.0 mEq/L
normal calcium range
9.0-10.5 mg/dL
(2.25-2.62 mmol/L)
normal chloride range
98-106 mEq/L
normal magnesium range
1.3-2.1 mEq/L
(0.65-1.05 mmol/L)
sodium often enters the body through
foods and fluids
- smoked or pickled foods, snack foods, condiments
where sodium goes, ___ follows
water
major cation of ICF:
potassium
potassium is highest in what? (food)
- meat
- fish
- many vegetables
- fruits
calcium enters the body through
intake of dairy products
- milk
- cheese
- yogurt
absorption of calcium requires what vitamin?
the active form of Vit D
calcium stored in what part of the body?
bones
what hormone is released when more calcium is needed?
PTH (parathyroid hormone)
what hormone is present when there is excess calcium?
the thyroid gland secretes TCT (thyrocalcitonin)
magnesium is stored in what body parts?
- bone
- cartilage
magnesium assists with:
- skeletal muscle contration
- carbohydrate metabolism
- generation of energy stores
- vitamin activation
- blood coagulation
- cell growth
dehydration: nursing priorites
- fluid replacement-IV fluids
- drug therapy
- patient safety
difference in treatment of mild vs severe dehydration
mild: regular fluids
severe: IV fluids
assessments for fluid overload
- shortness of breath
- edema
- crackles in lungs
- high BP
- distention of jugular vein
fluid overload: nursing priorities
- patient safety (falls)
- restore normal fluid balance
- prevent future fluid overload
- drug therapy: diuretic (ie. furosemide- monitor electrolytes with diuretics)
- nutrition therapy (low-sodium diet)
- strict monitoring of I/O’s, daily weights
IV potassium causes what sensation to patients?
burning
