12. Fluid Volume and Electrolytes Flashcards
3 categories of extracellular fluids
- interstitial: surrounds the cells
- intravascular: within blood vessels
- transcellular (third space): mucus, GI secretion, CSF, synovial, pericardial, and ocular fluids
fluid found inside the cells
intracellular fluid
number of particles dissolved in the serum (mainly Na, glucose, and urea)
osmolality
normal osmolality of human blood
275-295 mOsm/kg
fluid that has the same weight proportion of particles in water
isoosmolar
fluid that contains fewer particles than water
hypoosmolar
fluid that contains more particles than water
hyperosmolar
measurement of concentration of IV solutions compared w/ osmolality of body fluids
tonicity
characteristics of hemostasis
- anions and cations are balanced
- fluid compartments are in osmotic equilibrium
4 types of fluid and particle movement
- osmosis
- diffusion
- hydrostatic pressure
- active transport
common electrolytes in serum
- K (major intracellular cation)
- Na (major extracellular cation)
- Mg
- Ca
- Cl
- phosphorus (phosphate)
- sulfate
- H
- HCO3
movement of water across a semipermeable membrane from areas of low solute concentration to areas of high solute concentration
osmosis
movement of particles from an area of high concentration to low concentration
diffusion
force within a fluid compartment
hydrostatic pressure
requires metabolic activity and the use of energy to move a substance across a cell membrane
active transport
fluid replacement considerations
- all routes of fluid intake and loss
- daily water requirements
- water, electrolytes, and protein requirements
- patient weight and caloric need
- body surface area
- illness
- surgery
types of IV solutions
- crystalloids (includes isotonic, hypertonic, and hypotonic)
- colloids
- blood and blood products
- lipid emulsion
characteristics of crystalloid IV solution
- fluid and electrolytes only
- move freely across capillary walls
- don’t contain proteins
- short-term maintenance therapy
- may be isotonic, hypotonic, or hypertonic
uses of crystalloid IV solution
treat dehydration and electrolyte imbalances
examples of crystalloid IV solution
- dextrose in water (D5W): isotonic unless continuous or rapid
- norma saline (0.9% NSS): isotonic
- lactated ringers
explain hypotonic IV solution
- less osmolality
- allows fluid to move into cells
- can rupture RBCs in excess (fluid shifting into cells)
- may see decreased BP and decrease vascular fluid volume
explain hypertonic IV solution
- exerts greater osmotic pressure than extracellular fluid
- pulls fluid to vascular fluid and away from intracellular fluid
- causes cellular shrinkage
- monitor for circulatory overload (ex CHF)
characteristics of colloid IV solution
- contain protein or other large molecular substances that increase osmolality without decrease in solution
- don’t pass through semipermeable membranes in capillaries
- remain in intravascular space and pull fluid from interstitial space into plasma
- can be called “volume expanders”
examples of colloid IV solutions
- dextran solutions
- albumin
- Hetastarch
examples of blood and blood products
- whole blood
- packed RBCs (most common) - due to less fluid volume overload
- plasma
- platelets
examples of blood and blood products
- whole blood
- packed RBCs (most common) - due to less fluid volume overload
- plasma
- platelets
characteristics of blood for transfusion
- use 19G needle (usually 18G)
- once out of refrigerator must be administered within 4 hours
- use Y tubing w/ micro-aggregate filter tubing
- isotonic NS used w/ infusion
characteristics of lipid emulsions
- part of total parenteral nutrition (TPN)
- must be given through central line or PICC line (diluted in large vessel)
- high risk for infection
electrolyte functions
- transmission and condition of nerve impulses
- contraction of cardiac, skeletal, and smooth muscles
- normal kidney function
- change carbs to energy
- change AA to proteins
- role in acid-base balance
- regulates osmolality of cellular fluids
normal serum range of K
3.5-5 mEq/L
functions of K
- transmission and conduction of nerve impulses
- condition of cardiac, skeletal and smooth muscles
- enzyme action to change carbon, hydrogen, and O2 to energy and AA to proteins
- promotes glycogen storage in liver
- promotes osmolality of cellular fluids
sxs of hypokalemia
- N/V
- dysrhythmias
- ABD distension
- soft flabby muscles
sxs of hyperkalemia
- nausea
- stomach cramping
- tachycardia (initial bradycardia)
- oliguria
- weakness/numbness/tingling
correction of hypokalemia
- replace K oral (w/ food or at least 8oz of water or juice) or IV (more severe)
- encourage foods w/ K (fruits, vegetables, and fruit juice)
T/F: IV K causes irritation to peripheral vessels
True
correction of hyperkalemia
- restrict K intake (includes salt substitutes)
- IV Na bicarb, insulin w/ glucose (more serious)
normal serum Na
135-145 mEq/L
functions of Na
- transmission and conduction of nerve impulses
- maintain water balance
- maintains Na/K pump
- promotes acid-base balance
sign of hyponatremia
- muscle weakness
- headaches
- lethargy
- confusion
- seizures
- ABD cramps
- N/V
- tachycardia
- hypotension
signs of hypernatremia
- flushed dry skin
- agitated
- elevated body temp
- elevated BP
- rough dry tongue
- N/V anorexia
- tachycardia
- muscle twitching/hyperreflexia
normal Ca range
8.6-10.2 mg/dL
functions of Ca
- promotion of normal nerve and muscle activity
- aids in heart contraction
- maintains cellular permeability
- promotes blood clotting
- promotes bone and teeth formation
sxs of hypocalcemia
- bone fractures
- anxiety
- irritability
- tetany
- siezures
- Trousseau sign
- Chovstek sign
- EKG changes: prolonged QT interval and elongated ST segments
sxs of hypercalcemia
- fatigue
- muscle weakness
- depressed deep tendon reflexes
- confusion/impaired memory
- anorexia
- N/V
- constipation
- kidney stones
- EKG changes: shortened QT and ST segments and bradycardia
correction of hypocalcemia
- oral replacement (may be IV if severe)
correction of hypercalcemia
- correct the cause
- use IV saline to dilute
- calcitonin and diuretics (promote rapid excretion of Ca)
normal range of Mg
1.5-2.5 mEq/L
function of Mg
- promotion transmission of neuromuscular activity and cardiac contraction
- activates enzymes for metabolism
- promotes transportation of Na and K across cell membranes
sxs of hypomagnesemia
- neuromuscular excitability
- loss of deep tendon reflexes
- hypotension
- cardiac dysrhythmias
sxs of hypermagnesemia
- lethargy
- weakness
- paralysis
- loss of deep tendon reflexes
- hypotension
- heart block
foods high in Mg
- green vegetables
- fruits
- nuts/grains
- fish
normal serum range of chloride
96-106 mEq/L
function of chloride
- principle anion in ECF
- acid-base balance
- gastric juice for acidity
- maintains osmolality of ECF
sxs of hypochloremia
- tremors
- twitching
- slow shallow breathing
- hypotension
sxs of hyperchloremia
- weakness
- lethargy
- deep rapid breathing
- unconsciousness
normal range of phosphorus
2.4-4.4 mEq/L
functions of phosphorus
- major anion in ICF
- bone and teeth formation
- neuromuscular activity
- important component of DNA and RNA
- maintains cellular osmotic pressure
- supports acid-base balance
sxs of hypophosphatemia
- muscle weakness
- tremors
- paresthesia
- bone pain
- hyporeflexia
- seizures
- hyperventilation
- anorexia and dysphagia
sxs of hyperphosphatemia
- hyperreflexia
- tetany
- flaccid paralysis
- muscle weakness
- tachycardia
- nausea
- diarrhea
- ABD cramping
foods high in phosphorus
- whole grain cereal
- nuts
- milk
- meat
which electrolyte is a separate blood test from the rest
Mg
