Disorders of Fluid, Electrolyte, & Acid-Base Imbalaces Flashcards
Intracellular fluid
fluid inside the cells
Extracellular fluid
fluid outside of the cells
Interstitial fluid
fluid between the cells
Intravascular fluid
fluid inside the blood vessels
Transcellular fluid
third space Ex: CSF and eye
Thirst mechanism
triggered by decreased blood volume and increased osmolarity
Antidiuretic hormone (ADH)
- Promotes reabsorption of water in the kidneys
- Produced by the hypothalamus
Aldosterone
Increases re-absorption of sodium and water in the kidneys
Atrial natriuretic peptide (ANP)
stimulates renal vasodilation and suppresses aldosterone, increasing urinary output
-comes from the atrium in response to too much fluid in the heart
Isotonic
equal solute concentrations; no fluid shifts
- normal saline
- lactated ringers
Hypotonic
lower solute concentrations; causes fluids to shift out of vasculature and into cell
-0.45% saline
Hypertonic
Higher solute concentrations; causes fluids to shift into ECF & vasculature and out of the cell
-5% dextrose in NS; 3% saline
Major illnesses caused by fluid imbalance
Heart Failure
Renal disease
Trauma (blood loss)
Therapeutic measures for illness caused by fluid imbalance
IV fluids
Medication (diuretics)
NPO status
NG suctioning
Causes of hypovolemia
Inadequate fluid intake excessive fluid losses/ dehydration Fluid shifts Fever Decreased blood volume and plasma
Manifestations of hypovolemia
- Tachy then brady
- increased cap refill
- outcome is shock
Causes of hypervolemia
- Edema
- Fluid volume excess
- Water intoxication
Sodium (Na)
- normal level 135-145 mEq/L
- regulates ECF volume and osmolarity
- water follows salt
Causes of hypernatremia
- dehydration
- overuse of IV solutions
- impaired renal function
- Na administration
Causes of hyponatremia
- excessive water
- loss of Na from vomiting, diarrhea, GI suctioning, sweating
- use of diuretics, renal disease
Manifestations of hypernatremia
- increased temperature
- increased thirst
- irritability, agitation
- decreased urine output
Manifestations of hyponatremia
- anorexia, GI upset
- poor skin turgor
- diminished deep tendon reflexes, muscle weakness
Chloride (Cl)
- normal levels 96-106 mEq/L
- most abundant extracellular anion
- works with Na to maintain osmotic pressure in serum
- Increase and decrease due to similar factors that affect Na
Potassium (K)
- normal level 3.5-5 mEq/L
- maintains intracellular osmolarity
- controls cell resting potential
- small changes = cardiac muscle effects
- works opposite of Na
Causes of hyperkalemia
- Deficient excretion
- Excessive K intake
- Increased K release from cells
Causes of hypokalemia
- Excessive K loss
- deficient K intake
- increased shift into the cell
Manifestations of hyperkalemia
- respiratory depression
- abdominal cramping
- nausea and diarrhea
Manifestations of hypokalemia
- leg cramps
- hypotension
- decreased bowel sounds
- abdominal distention
- constipation, ileus
What will happen to blood K+ levels when the client has hyperaldosteronism?
Hypokalemia
What will happen to blood K+ levels when the client has alkalosis?
Hyperkalemia
What will happen to blood K+ levels when the client has an injection of epi?
hypokalemia
What will happen to blood K+ levels when the client has convulsions?
Hypokalemia
What will happen to blood K+ levels when the client has loop diuretics?
Hypokalemia
Calcium (Ca)
- normal levels 8.5-10.8 mEq/L
- closely regulated by kidneys & parathyroid hormone
- inverse relationship with phosphorus
- synergistic relationship with magnesium
Calcium is regulated by..
- Vitamin K
- parathyroid hormone
- Calcitonin- comes form the thyroid; thyroid problems equal calcium problems
Causes of hypercalcemia
- increased intake or release
- deficit excretion
Causes of hypocalcemia
- excessive losses
- deficient intake
Manifestations of hypercalcemia
- decreased memory
- headache
- muscle weakness, decreased deep tendon reflexes
Manifestations of hypocalcemia
- increased bleeding tendencies
- increased deep tendon reflexes, muscle spams, tetany
- seizures
- laryngeal spasms*
- positive Trousseau’s sign
- positive Chvostek’s sign
Phosphorus
- normal levels 2.5-4.5 mg/dL
- bone and ATP formation
- glucose, fat, protein metabolism
- inverse relationship with calcium
- acid base buffer
Magnesium (Mg)
- normal levels 1.3-2.1 mg/dL
- cofactor in enzyme reactions
- ATP generation
- DNA replication
- Blocks K+ exit from cardiac cells
- Smooth muscle relaxant
Causes of hypermagnesemia
renal failure
excessive laxative and antacid use
Causes of hypomagnesemia
- inadequate intake
- chronic alcoholism
- malnutrition
- pregnancy
- diarrhea
- stress
Manifestations of hypermagnesemia
Similar to hypercalcemia; think RENAL: Reflexes decreased EKG changes N/V Appearance flushed Lethargy/drowsiness/coma
Manifestations of hypomagnesemia
Similar to hypocalcemia
Acid (H+)
controls respiratory rate
Volatile acid
H2CO3
Nonvolatile acid
- Lactic acid: energy metabolism
- Hydrochloric acid: digestion
- ketoacids: “food” for brain
pH
- normal value 7.35-7.45
- regulated by chemical buffer systems and lungs (eliminate CO2)
- kidneys eliminate H+, reabsorb/generate HCO3-
Metabolic acidosis
- increased H+ = low pH
- decreased bicarbonate
- heavier breathing causes decreased PCO2
Metabolic alkalosis
- decreased H+ = high pH
- increased bicarbonate
- lighter breathing causes increased PCO2
Respiratory acidosis
- increased PCO2
- increased carbonic acid
- increased H+ = low pH
- increased bicarbonate
Respiratory alkalosis
- decreased PCO2
- decreased carbonic acid
- decreased H+ = high pH
- decreased bicarbonate
