Fluid and Electrolytes Flashcards
Measurable intake
oral fluid, tube feedings, parentral fluids, enemas, retained irrigation fluid
Non-measurable intake
solid foods, metabolism
Measurable output
urine, emesis, feces, drainage from body cavities
Non-measurable output
sweating, vaporization through the lungs
Intake sources
liquids, solid foods, metabolism
Fluid loss routes
kidneys, skin, lungs, GI tract, drainage
Sodium
- Major extracellular electrolyte
- Controls regulation and water balance
- Imbalances cause neuro problems
Potassium
- Major intracellular electrolyte
- Helps maintain intracellular water balance
- Transmits nerve impulses to muscles and contract skeletal and smooth muscles
- Levels increase with poor kidney function and decrease with excessive urination, diarrhea, and vomiting
- Imbalances cause cardiac problems
Chloride
- Works with sodium to maintain osmotic pressure
- increase with poor kidney function and decrease with excessive vomiting or diarrhea
Calcium
- Transmission of nerve impulses, heart and muscle contractions, blood clotting, formation of teeth and bones
- Requires vitamin D for absorption
Phosphate
-Balance intertwined with calcium
Serum osmo
- Increase water deficit (concentrated)
- Decrease water excess (dilute
Distribution of body fluids and electrolytes
-Intracellular (2/3)- potassium, phosphate
-Extracellular (1/3)- sodium, chloride
Body water:
-Extracellular 33% -Interstitial 25%-Plasma 8%
-Intracellular 66%
JG cells
- Sense low sodium
- releases renin
- Converts angiotensinogen to angio 1 then to angio 2
- Stimulates the release of Aldosterone
Adrenal Cortex
- Senses decreased serum osmo or sodium
- Releases aldosterone
- reabsorbs sodium into the blood
- increases potassium excretion into urine
- increases serum osmo
Hypothalamus
- senses increase in serum osmo or sodium
- stimulates thirst
- triggers release of ADH
- retains water in blood
- concentrates urine
- mildly constricts blood vessels
- decreases serum osmo
Heart
- senses increase volume through stretch receptors in right atrium
- secretes ANP and BNP
- inhibits ADH
- stops RAAS
- increased sodium excretion through the urine dilates blood vessels
- decreases serum osmo
Fluid spacing
- 1st spacing: Normal
- 2nd spacing: Edema
- 3rd spacing: ascites, burn edema
Isotonic IV fluids
- balanced, maintenance
- NS, D5W, LR
Hypertonic IV fluids
- shifting fluid out of the cell causing it to shrink
- 3% NS, D51/2NS, D10W
Hypotonic IV fluids
- shifting fluid into the cell causing size to increase
- 1/2 NS
hx considerations for fluid and electrolyte imbalances
-Nutrition, I/Os, insensible losses, use of diuretics/ laxatives, weight changes, kidney or endocrine disorders, LOC, mental status, depression, eating disorders, alcohol intake
physical considerations for fluid and electrolyte imbalances
-hydration status, skin turgor, mucous membranes, I/Os
Dx tests for fluid and electrolyte imbalances
-electrolyte levels, BUN, glucose, creatinine, pH, bicarb, osmolality, Hgb, Hct, urine dipstick, urine pH and specific gravity
Plasma
- Extracellular fluid (ECF)
- the fluid portion of the blood
Interstitial fluid (IF)
- Extracellular fluid (ECF)
- fluid in spaces between cells
Intracellular fluid (ICF)
-fluid contained in cells
ECF cation/anion
- Sodium is the chief cation
- Chloride is the major anion
ICF cation/anion
- Potassium is the chief cation
- Phosphate is the chief anion
Sodium/potassium pumps
-Continually readjust the concentrations so that there is more sodium in the ECF and more potassium in the ICF
ADH
- stored in the pituitary
- acts on the kidneys decreases the amount of water that is lost in urine, making it more concentrated
- alcohol inhibits the release of ADH
- decreased BP and plasma volume means that the baroreceptors aren’t being stretched which stimulates ADH
Atrial Natriuretic Peptide (ANP)
- Promotes excretion of sodium and chloride followed by water excretion to decrease blood volume
- Released by heart tissue in response to increased stretch
- Acts on the kidney
