Fluids & Electrolytes Flashcards
Hydrostatic pressure
- pressure based on amount of fluid in vessels (mainly capillaries)
- oncotic pressure outside vessels keeps balance
What is osmolality?
Number of particles dissolved in a fluid
ie. serum and urine
Types of fluid concentrations
- isoosmolar = balanced, no net movement
- hypoosmolar = more water than solutes (edema)
- hyperosmolar = more solutes than water (dehydration)
What is tonicity?
concentration of IV solutions in comparison to osmolality of body fluids
What should be considered for fluid replacement?
- all routes of fluid intake and loss
- daily water requirements (2300-2900mL/day for adults)
- water/electrolyte/protein (15-20g/meal) requirements
- pt weight, caloric needs, body surface area
- illness, surgery
Types of IV solutions
crystalloids (iso/hypo/hyper), colloids, blood and blood products, lipid emulsions
Crystalloids
used for short-term maintenance, dehydration, and electrolyte imbalance
Which IV solutions are iso, hypo, and hypertonic?
iso: D5W, 0.9% NaCl (NS), LR
hypo - 0.45% NaCl (1/2 NS)
hyper - 3% NaCl, D5 1/2 NS, D5 NS
LR is similar to blood plasma, D5 1/2 NS is physiologically hypertonic
Colloids
big proteins, volume expanders
Dextran, albumin, hetastarch
Blood products
- whole blood (~500mL) = everything
- Packed red blood cells (PRBCs) (~350mL) = RBCs w/o plasma and platelets; preferred b/c of O2 carrying capability w/o extra volume
- plasma
- platelets
Lipid Emulsions
- phospholipid solutions
- used for parenteral nutrition
Electrolyte functions
nerve impulses, muscle contraction, kidney function, ATP production, protein production, acid-base balance, cellular fluid osmolality regulation
Potassium
K+
- major intracellular cation
- major electrolyte for cardiac system
- 3.5 - 5 mEq/L
- administered orally, or IV drip (never pushed)
- foods: banana, citrus, tomatoes
- diuretics, laxatives, antibiotics, and steroids can affect levels
Hypokalemia
Symptoms mild to severe
- <3.5 mEq/L
- muscle weakness, fatigue, anorexia, nausea, vomitting, paresthesia, leg cramps, decreased bowel motility, palaytic ileus, confusion, rhabdomyolysis, myoglobinuria, dysrhythmias, cardiac arrest, respiratory arrest, death
Hyperkalemia
Symptoms mild to severe
- > 5 mEq/L
- dysrhythmias, tachycardia followed by bradycardia, paresthesia of face, tongue, hands, and feet, GI hyperactivity (N/V/cramping), metabolic acidosis
Sodium
Na+
- major extracellular cation
- major neurological electrolyte
- 135 - 145 mEq/L
- dietary requirement <2g/day
- foods: processed foods, meats
Hyponatremia
- <135mEq/L
- muscle weakness, decreased reflexes, headaches, confusion, lethargy, abdominal cramps, N&V, pallor, dry mucous membranes, cerebral edema, altered mental status, confusion, seizure
corrected via NS, 3% Saline, 5% saline depending on serum sodium level
Hypernatremia
- > 145mEq/L
- dry/sticky mucous membranes, flushed/dry skin, agitation, elevated body temp, rough/edematous/dry tongue, N/V, anorexia, tachycardia, hypertension, muscle twitching, hyperreflexia, cerebral dehydration, seizure, coma
Calcium
Ca2+
inverse to P, proportional to Mg
- most abundant mineral in body
- major electrolyte for musculoskeletal system
- 8.6 - 10.2 mg/dL total serum
- 4.64 - 5.28 mg/dL ionized
- more than 90% in bones/teeth, half of remaining bound to albumin, rest ionized (free)
- foods rich in vitamin D
acidosis = increased ionized, alkalosis = decreased ionized
decreased albumin = decreased total calcium (ionized unaffected)
Hypocalcemia
- <8.6 mg/dL
- anxiety, irritability, tetany, twitching, hyperreflecia, spasms of hands/wrists/feet/ankles, spasmodic contractions, laryngeal spasms, seizures, decreased cardiac output, dysrhythmias
twitch, twitch, seize, seize, chvostek’s, trousseau’s
Hypercalcemia
- > 10.2 mg/dL
- fatigue, muscle weakness, hyporeflexia, confusion, impaired memory, anorexia, N/V, constipation, kidney stones, decreased heart rate, dysrhythmias
Magnesium
Mg
- maintains Ca2+ and K+ balance
- major for neuromuscular control
- 1.5 - 2.5 mEq/L
Proportional relationship w/ Ca2+
Hypomegnesemia
- <1.5 mEq/L
- asymptomatic until ~ 1 mEq/L
- neuromuscular excitability, dysrhythmias, hypertension, tachycardia, v-fib
Hypermagnesemia
- > 2.5 mEq/L
- loss of deep tendon reflexes, lethargy, drowsiness, weakness/paralysis, hypotension heart block
Chloride
Cl-
- major anion in ECF
- 96 - 106 mEq/L
- acid-base balance, gastric acidity, osmolality of ECF
Hypochloremia
- <96 mEq/L
- tremors, twitching, slow & shallow breathing
Hyperchloremia
- > 106 mEq/L
- weakness, lethargy, deep & rapid breathing, unconsciousness
Phosphorus
- major anion in ICF
- 2.4 - 4.4 mEq/L
- bone/teeth formation, neuromuscular activity, cellular osmotic pressure, acid-base balance, DNA/RNA, intracellular energy transfer
inverse relationship w/ Ca2+
Hypophosphatemia
- <2.4 mEq/L
- muscle weakness, tremors, paresthesia, bone pain, hyporeflexia, seizures, hyperventilation, anorexia, dysphagia, hemolytic anemia, platlet dysfunction, reduced oxygen transport
Hyperphosphatemia
- > 4.4 mEq/L
- hyperreflecia, tetany, flaccid paralysis, muscular weakness, tachycardia, nausea, diarrhea, abdominal cramping, chronic kidney disease
