Fluid And Electrolytes Flashcards
What do body fluids do
Transports nutrients and wastes to and from cells, acts as a solvent for electrolytes and non-electrolytes; plays role in maintaining body temp, digestion and elim, acid-base balance, lubrication of joints and body tissues
What is body fluid?
Water containing dissolved/suspended substances like glucose, electrolytes, and proteins
70% of body fluid is this
Intracellular
30% of body fluids is this
Extracellular—interstitial (between cells) and intravascular (blood plasma)
Osmosis
Mvt of water down the concentration gradient from low solute conc to high solute conc across a semipermeable membrane
Diffusion
Movement of molecules from high conc of molecules to low conc of molecules
When does osmosis stop
When conc difference is gone or when hydrostatic pressure builds and opposes further movement
What does water follow?
Electrolytes; driven by osmotic pressure
Colloids
Substances that inc colloid oncotic pressure by moving fluid from interstitial compartment to blood plasma compartment
3 primary colloids and how they are measured
Albumin, globulin, fibrinogen; total protein level
Factors that decrease colloid oncotic pressure
Age and overall malnutrition
How are colloids increased?
Colloid replacement fluid
What do fluids and colloids maintain in the body?
Pressure
Hydrostatic pressure
Force of fluid in a compartment pushing against a cell membrane or vessel wall; generated by BP; at a capillary level, pushes fluid out of vascular space into interstitial space
Oncotic pressure aka colloid oncotic pressure
Caused by plasma colloids like albumin that attract water, pulling fluid from tissue space into vascular space (capillaries)
Electrolytes
Electrically charged in solution; affect fluid balance, nerves, heart rhythm, acid-base balance
Electrolytes work together
Change in one affects change in another; give fluid of opposite charge to fix imbalance
Conc of electrolytes in the body are dependent on…
Intake, absorption (anatomy), distribution, excretion (can kidneys excrete)
Extracellular electrolytes
Na, Cl, HCO3
Intracellular electrolytes
Potassium, magnesium, phosphorous
Normal lab value of sodium
136-145 meq/L
Normal lab value of potassium
3.5-5 meq/L
Magnesium normal lab value
1.7-2.2 mg/dL
Calcium normal lab value
9-11 mg/dl
Phosphate normal lab value
3.2-4.3 mg/dl
Causes of hyponatremia
GI loss, vomiting, diarrhea, pee lots, skin loss—wound and burn, fasting, drinking excess water (polydipsia)
S/s of hyponatremia
Altered LOC, confusion, anorexia, muscle weakness, if severe, seizure and coma
Dilutional hyponatremia
Excess water that dilutes Na; sx are hypervolemia, inc BP, weight gain, bounding rapid pulse, inc urine specific gravity
Depletional hyponatremia and sx
Lack both Na and fluid; hypovolemia, Dec BP, tachycardia, dry skin, weight loss, Dec urine specific gravity
Tx for hyponatremia
Give Na SLOWLY to avoid large, rapid shifts; PO or IV usually IV with NS; restrict fluids for dilutional hyponatremia, treat the underlying problem
Sodium bicarbonate indication and MOA
Tx for hyponatremia; PO, long-term Na deficit; MOA: dissociates to give bicarbonate ion which neutralizes ion concentration and raises blood and urinary pH
Sodium bicarbonate SE
edema, cerebral hemorrhage, hypernatremia, electrolyte imbalance, flatulence, tetany, pulmonary edema, heart failure exacerbation
Vesicant
Kills surrounding cells; IV sodium bicarb is one (only given IV for metabolic acidosis, acid-base prob, or low Na chronically), IV calcium, maybe potassium…
NC for sodium bicarb
Monitor cardiac, ABGs, electrolytes, monitor IV and patency if given; many drug intx; give 1-3 hours before/after meals for better absorption
Hypernatremia causes
Caused by IVF, tube feed, near drowning in salt water, NOT Food, low water or excess water loss, cognitive impairment, fever, heatstroke
S/s of hypernatremia
Altered LOC, confusion, seizure, coma, thirst, dry stick membranes, cramps
Hypernatremia tx
Slowly add water or remove sodium, slowly remove tube feeds, focus on improved Na levels within 48 hours
Potassium functions and source
Cardiac muscle cell contraction, cell excitability; diet is main source; kidneys are main source of K loss—pee it out
Hypokalemia cause
Renal or GI loss from diuresis especially lasix; diarrhea, acid-base problem
Hypokalemia s/s
Cardiac rhythm problem—can be lethal, muscle weakness, leg cramp, Dec bowel mobility, constipation, nausea, ileus
Potassium Chloride
Tx/prevention for hypokalemia; give oral/liquid and DILUTE with water or juice bc tastes awful and can cause GI bleeds, N/V/D, give slowly through IV and ALWAYS dilute
Which patients can you give IV potassium to?
Only for pt with documented urine output and tele; dialysis and end stage renal may NOT get it; may cause phlebitis and pain
How to give IV potassium
Never give fast and NEVER PUSH; <40 mEq, rate below 10-20 mEq
Hyperkalemia causes
Dec K output (renal failure, not peeing), burns, crush injuries, sepsis—massive cell injury, K-sparing diuretics, ACEs, ARBs
S/s hyperkalemia
Cardiac rhythm disturbance, muscle cramps, muscle weakness, peaked T waves
Kayexalate/sodium polystyrene sulfonate
Cation exchange resin that binds to K in digestive tract replacing K with Na; given in oral suspension, oral/rectal powder, rectal enema
SE and NC for Kayexalate
Poop out the K so only for people with normal bowel function; N/V/D, constipation, hypokalemia, intestinal obstruction, intestinal necrosis
D50/Insulin for Hyperkalemia
Usually for emergencies where cardiac rhythm disturbance is seen; combo shifts potassium into cell temporarily; give 10 units of insulin and 1 ampule of D50 (D50 prevents blood sugar from getting super low); check blood sugar and may give again
Magnesium functions
Stabilizes cardiac muscle and blocks/control Mvt of K+ out of cells, stabilizes smooth muscle
Causes of hypomagnesemia
Diuresis, GI/renal loss, pancreatitis, alcohol abuse, limited intake, hyperglycemia
Hypomagnesemia s/s
Hyperactive reflux, confusion, cramp, seizure, tremor, NYSTAGMUS—eyes drift
hypomagnesemia tx
Give PO or IV (Mylanta or Magnesium sulfate) or IV (magnesium sulfate/oxide) given over several days often (can IVP if needed)
Causes of hypermagnesemia
Inc intake accompanied by renal failure; chronic renal failure who take milk of magnesium (for constipation), OB patients (given mag sulfate to prevent preeclampsia sx)
Hypermagnesemia s/s
Lethargy, floppy, muscles weak, Dec reflex, flushed/warm skin, Dec pulse and BP
Hypermagnesemia tx
Stop replacement; if chronic replacement—dialysis
Mag sulfate and oxide s/s
Hypermagnesemia, slow Mvt, SOB, nausea, dizziness, abnormal heart rhythm
Mag oxide
Antacid—can be given for long term low mag
Calcium
Controlled by thyroid and parathyroid glands and released from and absorbed into bone
Where is most calcium located
In bones—99%; mostly protein bound, ionized and ready for use
Calcium functions
Stability and strength, enzyme reactions, membrane potential, muscle contractions, NT release, cardiac contrast, blood clotting
Causes of hypocalcemia
Calcium can’t mobilize from bones bc hypoparathyroidism, Hypomagnesemia, inc renal loss, renal failure, inc binding issues, Dec abs of vit D, acute pancreatitis, THYROID and PARATHYROID surgery (removal)
Sx of hypocalcemia
Inc neuromuscular activity—Parasthesias (numb/tingle), muscle cramps, bone pain, tetanus, laryngeal spasm, hyperactive reflexes, cardiac insufficiency (fatal arrhythmia), positive Chvostek’s sign, positive Trosseau’s sign
Positive Chvostek’s sign
Twitching in cheek muscle and eye close when facial nerve anterior to ear is tapped
Positive Trousseau’s sign
Spasm in carpal muscle when BP cuff is inflated
Tx of hypocalcemia
IV calcium—CaCl or calcium gluconate—both thru central line (vesicant); oral calcium—elemental calcium, calcium carbonate (tums), give vit D
Hypercalcemia causes
Caused by hyperparathyroidism, cancers (breast and lung), tums overdose
Hypercalcemia s/s
Sedative, fatigue, lethargy, confusion, seizure, coma; kidney stones if chronic
Hypercalcemia tx
Hydrate, diuretic with NaCl, dialysis
Phosphorous function
Works with calcium inversely (high Calcium, low phosphorous and vice versa); found mostly in bone and some Intracellular
Organic phosphate
Intracellular, we don’t measure
Inorganic phosphate
Circulates in bloodstream; we measure
Phosphate functions
Bone formation, ATP formation, enzymes needed for glucose, protein, fat metabolism, DNA and RNA; acid-base buffer, normal function of WBCs and platelets
Hypophosphemia causes
Rare; caused by Dec abs, antacids overdose, severe diarrhea, inc kidney elim, malnutrition (alc, TPN, recovery from manutrition)
Hypophosphatemia s/s
Tremor, parathesia, confusion to coma, seizure, muscle weakness, joint stiffness, bone pain, hemolytic anemia, pit dysfunction, impaired WBC function, kidney problems
Hyperphosphatemia causes
Kidney failure, lax/enema with phosphorus, intro-extra shift, stroke, heat, trauma, hypoparathyroid
Hyperphosphoremia s/s
Asymptomatic often; muscle spasm, paresthesia, tetany
Hypophosphatemia tx and NC
IV or oral replacement; given IV over a long time; inc oral intake, take care with CKD or Hypercalcemia (inc risk of calcifications)
Hyperphosphatemia tx
Treat the cause—calcium-based phosphate binders, hemodialysis—renal failure
Osmotic pressure
The amt of pressure needed to prevent the Mvt of water across a cell membrane
