Fluids and Electrolytes Flashcards
define homeostasis
Body fluids are regulated by fluid intake, hormonal controls and fluid output, in order to maintain homeostasis (which is essential to for survival). It is the body’s ability to respond to changes.
Identify the fluid compartments and subcompartments of the body and the relative volumes in each.
Intracellular (ICF):
o All fluid within body cells, accounting for approx.
66% of total body water and 40% of body weight
Extracellular (ECF):
o All the fluid outside cells, is divided into 3 smaller
compartments:
- Interstitial fluid : including lymph, is the fluid
between the cells and outside the blood vessels
- Intravascular fluid: is blood plasma
- Transcellular fluid : separated from other fluid by
epithelium, includes cerebrospinal, pleural,
peritoneal, and synovial fluids and the fluids in
the gastrointestinal tract
Identify the routes of water intake and output to and from the body
Fluid Output: occurs through 4 organs of water loss: the kidneys, the skin, the lungs, and the gastrointestinal tract
Fluid Intake: is regulated primarily through the thirst mechanism. Thirst control centre is located within the brain’s hypothalamus.
Assessments to evaluate body fluid volume status?
· Daily weight
· Measuring intake and output
· Laboratory studies, review lab data, including serum and urinary electrolyte levels, hematocrit, blood creatinine level, blood urea nitrogen levels…
· Arterial blood, gases to determine ABG levels, a sample of the blood from and artery bust be taken
· Physical and behavioral nursing assessment
Define diffusion
is the movement of ions and molecules in a solution across a semipermeable membrane from an area of higher concentration to an area of lower concentration. The result is an even distribution of the solute in a solution. The rate of diffusion is affected by the molecule size, concentration and temperature of the solution
Define Facilitated diffusion and Active transport
Facilitated diffusion and Active transport are 2 examples of carrier-mediated transport where molecules are moved across the plasma membrane. One is carred across the membrane by a protein such as insulin that binds to glucose ( facilitated) and the other requires energy to move materials across cell membranes against a concentration gradient (active) ex: sodium-potassium pump
Define Osmosis
is the movement of water through a semipermeable membrane from an area of lesser solute concentration to an area of greater solute concentration in attempt to equalize concentrations on both sides of the membrane.
Define Osmolarity
reflecting the osmolar concentration in 1 L of solution most often used to describe fluids outside the body (mOsm/L)
Define Osmolality
the concentration of a solution expressed as the total number of solute particles per kilogram
What is the difference between crystalloids and colloids
· Crystalloids:
o used most commonly and include glucose, sodium
chloride and lactated Ringer’s solutions
o contain solutes that mix, dissolve, and cross
semipermeable membranes.
o They vary in their tonicity
· Colloids:
o Contain protein or starches which does not cross
semipermeable membranes and therefore remain
suspended and distributed in the extracellular space,
primary the intravascular space, for up to several
days
o Used to increase the osmotic pressure in the
intravascular space to increase vascular volume in
critical situations
o Either semi-synthetic (dextran, pentastarch,
hetastarch) or human plasma derivatives(albumin,
plasma proteins or blood)
What is a hypotonic solution?
osmotic pressure lower than plasma, moves fluid into the ceslls, causing them to enlarge
What is an isotonic solution?
solution with the same osmolarity as blood plasma
What is an hypertonic solution?
a higher osmotic pressure pulls fluid from cells, causing them to shrink
Explain he mechanism of thirst
· The thirst mechanism will also be stimulated when excess fluid is lost and hypovolemia occurs, as in excessive vomiting and hemorrhage
What is an average adult’s fluid intake?
An average adult’s fluid intake is about 2200 to 2700 mL per day.
- oral intake accounts for 1100 to 1400mL, solid foods
800-1000 and oxidative metabolism for 300 mL/day
What is hyponatremia and hypernatremia ?
Sodium imbalances
What is hypokalemia and hyperkalemia?
Potassium imbalances
What is hypocalcemia and hypercalcemia?
Calcium imbalances
What is hypomagnesimia and hypermagnesemia?
Magnesium imbalances
What is hypochloremia and hychloremia?
Chloride imbalances
What are the 2 basic types of fluid imbalances?
Isotonic deficit
exist when water and electrolytes are gained or lost in equal proportions
Osmolar imbalances
are losses or excesses of only water, so the concentration of the serum is affected.
What are some purposes of water?
Hydration, transport, regulate our temperature, acts as a cushion, a solvent
Why do babies dehydrate more quickly than adults?
• Because they have a larger surface of skin/water and they can lose it from the skin. Also, their kidneys are not well developed and they do not conserve liquid as well.
Name some signs of dehydration
decreased output, dark urin, poor skin turgor, fatigue, headache, dry mucosa, decrease in tears, heart rate increase, BP wills stay normal for a while, but then it will drop which means its more severe
What is the normal serum for potassium?
3.5 – 5.0 mmol/L
What is the normal serum for chloride?
98 – 106 mmol/L
What is the normal serum for sodium?
136 – 145 mmol/L
What is the normal serum for magnesium?
0.65 – 1.05 mmol/L
What are the blood gases in the body?
pCo2 35 – 45 Hg (partial pressure of carbon dioxide)
p02 80 – 100 mm Hg (partial pressure of oxygen)
Sa02 95 – 99 %
Base excess ± 2
Bicarbonate 22 – 26 mEq/L
What is the normal PH for humans?
pH 7.35 – 7.45
What is acidosis ?
More H+ (lower number) = acidosis
What is alkalosis?
Less h+ (higher number) = alkalosis
What is the body’s total water weight in L
42 L
Thirst is regulated by what part of the brain?
Hypothalamus
Name the common electrolytes found in the body
Calcium Chloride Magnesium Phosphorous Potassium Sodium
the movement of fluid from capillaries to the interstitial space is called:
a) osmosis
b) diffusion
c) filtration
d) graduation
c) filtration
