aldosterone
acts on the distal convoluted tubule of the kidney to increase the amount of water and sodium reabsorbed back into the bloodstream, is released when the adrenal cortex is stimulated.
antidiuretic hormone (ADH)
A hormone secreted by the pituitary gland that maintains serum osmolality by controlling the amount of water excreted in the urine.
colloids
Substances such as proteins that do not dissolve easily.
crystalloids
substances that dissolve easily in water
dehydration
Hypertonic volume deficit occurs when water is lost in excess of sodium. As fluid loss continues, the circulating fluid volume decreases, and serum osmolarity increases. Even the small losses of fluids can lead to undesirable consequences. Severity of deh
diffusion
the movement of solutes across a selectively permeable membrane from areas of higher concentration to areas of lower concentration until equilibrium is reached. Diffusion is influenced by temperature, molecular weight, steepness of the concentration gradi
edema
the abnormal accumulation of fluid in the interstitial spaces, typically in the face, fingers, abdomen, ankles, and feet. Assessing fluid volume excess (FVE) is by looking at increased total body weight: a 2% gain is mild excess, 5% gain is moderate exces
electrolytes
Charged atoms or molecules(ions) that conduct electrical impulses across cells. They carry a positive charge(cations) or a negative charge(anion).
extracellular fluid
Fluid outside of the cell; interstitial, intravascular, or transcellular, this includes cerebrospinal, synovial, peritoneal, pleural, and pericardial fluids.
fluid volume deficit (FVD)
Occurs with excessive loss or inadequate intake of fluid. Two types of fluid deficits can occur: Isotonic and Hypertonic. Isotonic (Hypovolemia) occurs when water and sodium are lost at the same rate. Hypertonic occurs when water is lost in excess of sodi
fluid volume excess (FVE)
Fluid volume excess occurs when intake exceeds output. Fluid volume excess is isotonic or hypotonic, depending on corresponding changes in serum osmolarity.
Homeostasis
is the maintenance of fluid balance, is controlled by several physiological mechanisms, including the renin-angiotensin system, the secretion of the antidiuretic hormone, and the thirst mechanism. Homeostasis is monitored by the kidneys through changes in
hydrostatic pressure
Hydrostatic pressure is the force of the fluid pressing against the blood vessel; it is controlled by the force of myocardial contraction, rate of contraction and blood flow. The force, or pressure, is different on the arterial and venous sides of the cap
hyperkalemia
occurs when the serum potassium level is greater than 5.0 mEq/L. This imbalance results from excessive intake of potassium, transfusions and medications, impaired renal excretion, and cellular movement.
hypokalemia
occurs when the serum potassium level falls below 3.5 mEq/L. Inadequate intake occurs as a result of decreased oral intake or insufficient potassium in intravenous (IV) fluids.
Hypernatremia
occurs when the serum sodium level is greater than 145 mEq/L. This imbalance results from a greater loss of water compared with sodium or a greater intake of sodium.
hyponatremia
occurs when the sodium level is decreased in relation to body water. It is defined as a serum level less than 135 mEq/L.
hypertonic solution
pulls water from the cell to the extracellular fluid compartment, causing cellular shrinkage.
hypotonic solution
Excess water moves into the cells, producing cellular swelling.
hypovolemia
A decrease in fluid volume, specifically a condition marked by the loss of fluid and solutes from extracellular fluid that, if left untreated, can progress to hypovolemic shock.
isotonic solution
An administered solution that has the same osmolarity as blood plasma. the osmolality concentration is between 240 and 340 mOsm/kg (A milliosmole (mOsm) is 1/1,000 of an osmole)
milliequivalent
denotes the ability of cations to bond with anions to form molecules. Electrolytes are measured in milliequivalents per liter of water (mEq/L).
oncotic pressure
in the intravascular space is controlled by the concentration of plasma proteins, specifically albumin. This is known as colloid osmotic pressure, or oncotic pressure
orthostatic hypotension
When a patient moves from a lying or sitting position to a standing position, orthostatic hypotension can occur. There is a sudden drop in systolic pressure (20 mmHg drop) and a drop in diastolic pressure (10 mmHg drop). The low pressure occurs from perip
osmolality
refers to the number of osmoles (unit of pressure) per kilogram of solvent. This term is used interchangeably with osmolarity
osmolarity
the number of osmoles per liter of solvent. This term is used interchangeably with osmolality. For this chapter you will use osmolarity most often.
osmoreceptors
They monitor the osmolarity of the blood plasma and are located in the hypothalamus
osmosis
the movement of water across cell membranes; osmotic pressure
renin-angiotensin system
regulates blood pressure and fluid balance through vasoconstriction and excretion or reabsorption of sodium.
tonicity
the level of osmotic pressure of a solution; isotonic, hypertonic, hypotonic
three functions of water in the body
transports nutrients, regulates body temperature, lubricates joints
How does the body regulate fluid volume to maintain homestasis?
several body systems, and hormones help regulate. Water is brought into the body through intake of fluids or foods. Excreted as urine.
What is the average daily intake/output of fluids? (mL)
2500 mL
Why are infants TBW higher than older adults?
Infants have more extracellular fluid than intracellular fluid because they have a large body and lung surface area compared to their body mass, and they have immature kidneys that have little reserve capacity.
Why are older adults TBW lower than infants?
thirst sensation is blunted causing the osmolarity to rise before they realize they're thirsty, resulting in decreased fluid intake. Also, older adults have decreased lean body mass, which decreases their TBW percentage
What are risk factors for infants regarding fluid and electrolyte balance?
they are at risk because they have high levels of total body water
What are risk factors for elderly regarding fluid and electrolyte balance
They are more prone to hypokalemia because of diuretic use
What diagnostic tests should the RN monitor with alterations in fluid and electrolyte balance?
Levels of serum electrolytes, BUN, Serum osmolarity, RBCs, HGB, Hematocrit, Serum albumin, Urinalysis
What is fluid volume deficit (FVD)?
occurs with excess loss of inadequate intake of fluid.
isotonic FVD causes:
Hemorrhage, burns, vomiting, diarrhea, Addison disease, fever, excessive perspiration.
clinical manifestations of isotonic FVD are...
Confusion, thirst, dry mucous membranes, orthostatic hypotension, tachycardia, weak and thready pulse, decreased skin turgor, prolonged capillary refill, and decreased urinary output.
Lab findings of isotonic FVD...
Urine specific gravity >1.030, Increased hematocrit: Adult males >52; Adult females >48, BUN >20.
Nursing interventions for isotonic FVD
Administer fluids, monitor vital signs, monitor intake and output, monitor laboratory results, especially hematocrit, BUN, and urine specific gravity.
hypertonic FVD causes:
Diabetes insipidus, diabetic ketoacidosis,administration of osmotic diuretics, hypertonic enteral tube feedings, or hypertonic intravenous fluids; prolonged vomiting and diarrhea.
clinical manifestations of hypertonic FVD...
Similar to hypovolemia, dry sticky mucous membranes, flushed dry skin, increased body temperature, irritability, convulsions, and coma.
lab findings for hypertonic FVD
Urine specific gravity >1.030, Increased hematocrit: Adult males >52, Adult females >48, BUN >20, Serum sodium >145.
nursing interventions for hypertonic FVD
Administer fluids, monitor vital signs, monitor intake and output, assess for neurologic changes, monitor laboratory results, especially hematocrit, BUN, and urine specific gravity.
What is fluid volume excess (FVE)?
occurs when fluid intake exceeds output
isotonic FVE causes:
Congestive heart failure, renal failure, and cirrhosis.
clinical manifestations of isotonic FVE are
Weight gain, edema in dependent areas, bounding peripheral pulses, hypertension, JVD, dyspnea, cough, abnormal lung sounds.
lab findings for isotonic FVE
Urine specific gravity <1.005, decreased hematocrit: Adult males <42, Adult females <37, BUN <7.
Nursing interventions for isotonic FVE
Monitor vital signs, monitor intake and output, assess for edema and JVD, auscultate lung fields, monitor laboratory results, especially hematocrit, BUN, and urine specific gravity
hypotonic FVE causes
Excessive water intake, prolonged use of hypotonic IV solutions, SIADH (Syndrome of inappropriate antidiuretic hormone secretion)
clinical manifestations of hypotonic FVE
Symptoms similar to isotonic fluid volume excess plus neurologic changes that indicate cerebral edema, including decreased level of consciousness, coma, and convulsions
lab findings for hypotonic FVE
Urine specific gravity <1.005, decreased hematocrit: adult males <42, adult females <3, BUN <7, serum sodium <135
nursing interventions for hypotonic FVE
Monitor vital signs, monitor intake and output, assess for neurologic changes, monitor laboratory results, especially hematocrit, BUN, and urine specific gravity
What assessment changes would you expect with isotonic FVD?
Confusion, thirst, dry mucous membranes, orthostatic hypotension, tachycardia, weak and thready pulse, decreased skin turgor, prolonged capillary refill, and decreased urinary output
What assessment changes would you expect with hypertonic FVD?
Similar to hypovolemia, dry sticky mucous membranes, flushed dry skin, increased body temperature, irritability, convulsions, and coma
What assessment changes would you expect with isotonic FVE?
Weight gain, edema in dependent areas, bounding peripheral pulses, hypertension, JVD, dyspnea, cough, abnormal lung sounds
What assessment changes would you expect with hypotonic FVE?
Symptoms similar to isotonic fluid volume excess plus neurologic changes that indicate cerebral edema, including decreased level of consciousness, coma, and convulsions
normal range for sodium
135-145 mEq/L
What are food sources of sodium in the body?
Meats: especially red meats, fish, eggs and dairy: cheese and milk, yeast breads, soups, pastas and some fruits and veggies
What are four functions of sodium in the body?
is the principal ion responsible for resting membrane potential of cells, it is essential in depolarization and needed for nerve and muscle function, it's the principal cation of the extracellular fluid (it accounts for 90-95% of the osmolarity), and it p
What focused assessment should the nurse perform with an alteration in sodium?
neuromuscular, cognitive, and urinary intake/output assessements
normal range for potassium
3.5-5.3 mEq/L
What are food sources of potassium?
Milk, bananas, legumes, green leafy vegetables, orange juice, tomatoes, vegetable juice, avocados, and cantaloupe
What are three functions of potassium in the body?
Produces resting membrane potentials of nerve and muscle cells.
Principal cation of the intracellular fluid and responsible for intracellular osmolarity.
Essential component of the sodium-potassium pump and involved in protein synthesis.
What focused assessment should the nurse perform with an alteration in potassium?
cardiovascular, renal, and neuromuscular assessments
What are four nursing diagnosis for individuals with alterations in fluid and electrolytes?
Excess fluid volume, Decreased fluid volume, Impaired renal volume, and Decreased cardiac output.
What are some patient-centered interventions for individuals with alterations in Fluid & Electrolytes?
Some patient-centered interventions for individuals with alterations in fluid and electrolytes are restricting fluid intake, restricting electrolyte intake, fluid replacement, electrolyte replacement, and intravenous (IV) therapy.
What are outcomes/goals for individuals with alterations in Fluids & Electrolytes?
The patient will exhibit no edema within 48 hours, patient's intake and output will be balanced by the end of the next shift, urine specific gravity will be within the normal limits on the next urinalysis, patient's mucus membranes will be moist by the en
what are cyrstalloids
solutes that dissolve easily
what are colloids
solutes that do not dissolve easily
what fluid shift will occur in a isotonic solution
the solution has the same osmolarity as blood plasma. Isotonic solutions cause an equal amount of water to move into and out of the cell.
What fluid shift will occur in a hypotonic solution
the solution has a lower osmolarity than body fluids. Administering a hypotonic solution causes excess water to move into the cells, producing cellular swelling.
What fluid shift will occur in a hypertonic solution
the solution has a higher osmolarity than body fluids. Administering a hypertonic solution will cause water to move out of the cells causing cellular shrinkage