Fluid & Electrolytes Flashcards
Infusion therapy
fluid and electrolyte replacement
medication administration
blood product administration
and nutritional support
intracellular fluid
ICF 70%
is within cells and accounts for majority of the total body weight
Extracellular fluid
ECF 30%
Outside cells
interstitial fluid and plasma
Rapid changes of fluid compartments
risk highest for infants & elderly
Healthy person body water
total body water is 50% to 60% of body weight
infants compared to adults
More body fluid and extracellular fluid than an adult so they are more susceptible to fluid volume deficits
Things that affect body water
gender and amount of fat cells
women and obese people have less body water
Sodium (Na+)
Controls and regulates volume of body fluids
Potassium (K+)
chief regulator of cellular enzyme activity and water content
Calcium (Ca++)
b12 absorption, nerve impulse, blood clotting, and muscle contraction
Magnesium (Mg++)
Metabolism of carbohydrates and proteins, vital actions involving enzymes
Chloride (Cl-)
maintains osmotic pressure in blood, produces hydrochloric acid
Bicarbonate (HCO3-)
body’s primary buffer system
Phosphate (HPO4-)
involved in important chemical reactions in the body, cell division, and hereditary traits
Hyponatremia
a sodium deficit in ECF (<135mEq) caused by a loss of sodium or a gain of water
sodium may be lost through vomitting, diarrhea, fistulas, swearing, or as the results of the use of diuretics
the decrease in sodium causes fluid to move by osmosis from the less concentrated ECF compartment to the ICF space (swelling, confusion, hypotension, edema, muscle cramps and weakness and dry skin)
Severe hyponatremia
manifested by signs of increasing intracranial pressure (lethargy, muscle twitching, focal weakness, seizures and death may occur)
Hypernatremia
surplus of sodium in ECF (sodium >145) caused by excess water loss or an overall excess of sodium
fluid deprivation, lack of fluid consumption, diarrhea, and excess of insensible water loss (hyperventilation, burns) leads to excess sodium
fluids move from the cells because of the increased extracellular osmotic pressure, causing them to shrink and leaving them without sufficient fluid
results in neurologic impairment such as restlessness, weakness, disorientation, delusion, and hallucinations
permanent brain damage, especially in children can occur
Hypokalemia
refers to a potassium deficit in ECF (<3.5mEq) and is common electrolyte abnormality
potassium may be lost through vomiting, gastric suction, alkalosis, or diarrhea, or as the result of the use of diuretic
when the extracellular potassium level falls, potassium moves from the cell, creating an intracellular potassium deficiency and sodium and hydrogen ions are retained by the cells to maintain isotonic fluids.
Muscle weakness and leg cramps, fatigue, paresthesias, and dysrhythmias
Hyperkalemia
refers to an excess of potassium in ECF (serum potassium >5mEq/L)
excess potassium may result from renal failure, hypoaldosteronism, or the use of certain medications
less frequent than hypokalemia, but is more dangerous
nerve conduction as well as muscle contractility can be affected
skeletal muscle weakness and paralysis may occur and cardiac irregularities
Hypocalcemia
calcium deficit in ECF (serum calcium < 8.9mg/dl, ionized calcium <4.5mg/dL)
common causes involve inadequate calcium intake, impaired calcium absorption, and excessive calcium loss
numbness and tingling of fingers, mouth, or feet. Tetany, muscle cramps and seizures come about.
Hypercalcemia
refers to an excess of calcium in ECF
two major causes are cancer and hyperparathyroidism
nausea, vomitting, constiation, bone pain, excessive urination, thirst, confusion, lethargy, and slurred speech
severe hypercalcemia can lead to cardiac arrest
Hypomagnesemia
magnesium is the most abundant intracellular cation after potassium
magnesium loss may occur with nasogastric suction, diarrhea, withdrawal from alcohol, administration of tube feedings or parental nutrition, sepsis or burns
leads to muscle weakness, tremors, tetany, seizures, heart block, change in mental status, hyperactive DTRs, and respiratory paralysis
HYpermagnesemia
refers to magnesium excess in the ECF
usually occurs with renal failure when the kidneys fail to excrete magnesium or from excessive magnesium intake
includes nausea, vomitting, weakness, flushing, lethargy, loss of DTRs, respiratory depression, coma, and cardiac arrest
Hypophosphatemia
refers to a below normal concentration of phosphorus in the ECF
can result from administration of calories to malnourished patients, alcohol withdrawal, diabetic keto acidosis, hyperventilation, insulin release, absorption problems, and diuretic use
irritability, fatigue, weakness, paresthesias, confusion, seizures, and coma
Hyperphosphatemia
refers to above-normal concentrations of phosphorus in the ECF
common causes are impaired kidney exertion and hypoparathyroidism
can result in tetany, anorexia, nausea, muscle weakness, and tachycardia
Hypochloremia
refers to below normal level of chloride in the ECF
can result from severe vomitting and diarrhea, draining of gastric fluid, metabolic alkalosis, diuretic therapy, and burns
hyper excitability of muscles, tetany, hyperactive DTRs, weakness, and muscle cramps
Hyperchloremia
above normal level of chloride in the ECF
can result from metabolic acidosis, head trauma, increased perspiration, excess adrenocortical hormone production, and decreased glomerular filtration
signs and symptoms include tachypnea, weakness, lethargy, diminished cognitive ability, hypertension, decreased cardiac output, dysrhythmias, and coma
Osmosis
major method of transporting body fluids through cell membranes
water moves from an area of lesser solute concentration to greater solute concentration
Diffusion
is the tendency of solutes to move freely throughout a solvent
solute moves from high to low
oxygen and carbon dioxide also move by diffusion
Active transport
requires energy for movement for substances through the cell membrane from the less solute concentration to the higher solute concentration
filtration
passage of fluid through a permeable membrane from the area of higher to low pressure
Osmotic Movement of fluids
cells affected by osmolality of fluid surrounding it
Osmolality
concentration of particles is a solution –puling power
Osmolality of a solution
Isotonic hypertonic hypotonic
Isotonic
same concentration fo particles as plasma
hypertonic
greater concentration of particles than plasma
Hypotonic
lesser concentration of particles than plasma
Source of fluids for the body
ingested liquids, food, and metabolism
Fluid losses
Kidneys: urine
intestinal tract: feces
skin: perspiration
insensible water loss
Kidneys and homeostasis
Kidneys normally filter 170 L of plasma and excrete 1.5 L of urine
Cardiovascular system homeostasis
pumps and carries nutrients and water in the body
Lungs homeostasis
regulate oxygen and carbon dioxide levels of the blood
Adrenal glands homeostasis
helps the body conserve sodium, save chloride and water, and excrete potassium
Pituitary gland homeostasis
stores and releases ADH
Thyroid gland homeostasis
increases the blood flow in the body and increases renal circulation
Nervous system homeostasis
inhibits and stimulates mechanisms influencing fluid balance
Parathyroid homeostasis
regulate the level of calcium in ECF
GI tract homeostasis
absorbs water and nutrients that enter the body through this route
Hypovolemia
deficiency in amount of water and electrolytes in ECF with near-normal water/electrolyte proportions
Dehydration
decreased volume of water and electrolyte change
Third-space fluid shift
distributional shift of body fluids into potential body spaces
Fluid imbalances
hypovolemia, dehydration, and third-space fluid shift
Fluid Volume Excess
Hypervolemia, over hydration, edema, and interstitial to plasma shift
Hypervolemia
excess retention of water and sodium in ECF
Over hydration
above normal amounts of water in extracellular spaces
Edema
excessive ECF accumulates in tissue spaces
Interstitial to plasma shift
movement of fluid from space surrounding to blood
Isotonic IV solutions
ECF (circulating body volume) doesn’t enter cells
contain multiple electrolytes in roughly the same concentration as plasma
used as volume replacement in hypovolemic situations, such as dehydration, burns, severe vomitting or diarrhea, dKA
Hypotonic iv solutions
water moves into cells by osmosis and water goes from less to more
provide Na+, CL-, and free water
helps kidneys eliminate solutes and dilutes plasma
used to treat hypernatremia
Hypertonic
water goes from cells to ECF
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