pathpharm-fluids and electrolytes Flashcards
Water makes up _________-__________% of an infant’s total body composition
70-80
Water makes up _________-__________% of an adult’s total body composition
50-60
Water makes up _________-__________% of anolder adult’s total body composition
45-55
Within bodily fluid __________% is extracellular and ____________% is intracellular
20, 40
Within extracellular bodily fluid ________% is plasma, and _________% is interstitial fluid
5,15
Infants and elderly are both at risk for_________________
dehydration
List the 6 important properties of water (fluid)
- Universal solvent 2. lubrication 3. Transports O2, nutrients, wastes 4. regulates body temp.(high heat capacity) 5. shock absorber (joints) 6. Gives the body form
Define intracellular fluid:
fluid within cells
Define extracellular (plasma/intravascular) water:
fluid inside vessels but outside cells
Define extracellular (interstitial/3rd spacing) water:
fluid outside vessels and cells
_____________ is responisble for causing edema.
interstitial/3rd spacing fluid
What are the 3 major ECF ions?
NA+(sodium), Cl-(chloride), HCO3-
What are the major ICF ions?
K+, Mg++, HPO4-
Define osmolarity:
The measure of solute concentration in a solution
T or F: ICF and ECF are in osmotic equilibrium.
TRUE
What are the limits for a normal serum osmolarity?
275-290 Osm/L
If you wanted to determine a patient’s serum Osm without running a separate Osm test, what could you use to estimate the value?
Take the pt’s Na+ level and multiply by two to get estimated Osm. Ex: Na+= 145. 145x2=290, 290 would be the estimated Osm/L.
Define electrolyte:
solutes that form ions
A cation will have a______ charge, while an anion has a ________ charge.
positive, negative
What are the body’s major electrolytes that are cations?
Na+, K+, Ca++, Mg++
What are the body’s major electrolytes that are anions?
Cl-, HCO3-, HPO4–, SO4-
What is the largest determinant of Osm?
sodium level
Sodium is necessary for regulation of: a. blood & body fluids b. transmission of nerve impulses c. heart activity d. metabolic functions e.all of the above
e
What is the normal values for Na+?
135-145 mEq/L
This electrolyte is important for controlling INTRACELLULAR Osm, esp. in heart cells.
potassium
Potassium is important because it:
- regulates heart and muscle contractions 2. plays a role in nerve impulse conduction
Potassium is eliminated by:
the kidneys
T or F: Potassium affects the excitability of muscles.
TRUE
What is the normal potassium value?
3.5-5.0 mEq/L
Renal problems can cause __________ in relation to K+
hyperkalemia
Insulin will cause K+ to move from ____________ to _____________
ECF to ICF
Acidosis, trauma, and exercise cause K+ to move from ______________ to______________
ICF to ECF
Sugar, lipids, amino acids, uric acid, urea, and creatinine are examples of:
non-electrolytes
The major functions of HCO3 and H are:
acid/base balance
The electrolyte in charge of skeletal integrity, coagulation, neurotransmitters, and cardiac conduction is:
Calcium
The electrolyte involved in skeletal, energy/ATP is:
PO4
The electrolyte whose main functions include GI, neuro, and cardiac is:
Mg
T or F: Fluid/electrolyte disorders are when fluids and electrolytes interact with eachother to cause a harmful response for the host.
FALSE. Fluid/electrolyte disorders occur when there is a problem with the balance between electrolytes and fluids.
When a person drinks too much water they are at risk of________________in terms of electrolytes.
dilution
When a person does not drink enough water they are at risk of ________________ in terms of electrolytes.
increased concentration
What are the two main pressure gradients in our bodies?
hydrostatic pressure, oncotic pressure
What are two examples of hydrostatic pressure?
blood pressure, blood volume
Oncotic pressure refers to:
plasma proteins
ADH, aldosterone, renin-angiotensin, PTH, and naturietic hormone all work to:
regulate the fluid and electrolyte balance in our bodies
What is the main function of the kidneys?
to maintain a normal ECF level/concentration
T or F: Osmosis is the movement of solutes from an area of high to low concentration across a semi-permeable membrane.
FALSE! OSMOSIS refers to the movement of water NOT solutes.
Define diffusion:
The movement of SOLUTES from an area of high concentration to low concentration across a semi-permeable membrane.
What is the purpose of osmosis and diffusion?
to reach equilibrium on both sides of the membrane
Cell membranes have ______________________, which means some solutes cross freely, some cross with assistance, and others do not cross at all.
selective permeability
_______________ refers to an IV solution that contains small particles that can eventually cross semi-permeable membranes while a __________ IV solution contains large protein or sugar molecules that cannot cross membranes.
crystalloid, colloid
Define isotonic solution as it relates to IV fluids:
a solution that has a concentration of solute equal to that of normal body fluids
What is an example of an isotonic IV fluid?
Normal saline
Infusing a patient with an IV of .9%NSS (normal saline solution) will create what change in regards to body fluids?
No change-.9% is the same concentration as our body’s fluids, so fluid will stay where it is.
Define hypotonic solution in terms of IV fluids:
A solution with a solute concentration less than normal body fluids
What is an example of a hypotonic IV solution?
D5.45%NS (5% dextrose in half normal saline)
When infusing a patient with D5.45%NS, what will happen internally in regards to body fluids?
The IV solution will move from the intravascular space(portal of entry) into the interstitial space and into body cells
What is the danger of a hypotonic IV solution?
can cause cells to rupture
Define hypertonic solution in terms of IV fluids:
The particle concentration of the solution is higher than that of normal body fluids
What is an example of a hypertonic IV solution?
3.0% NaCl
Infusing a patient with an IV of 3.0% NaCl will create what change in regards to body fluids?
Fluid will move out of cells into the intravascular space (poratl of entry for IV fluid)
What is the danger of using a 3.0% NaCl solution?
Can cause cells to shrivel up and die
Define hydrostatic pressure:
any pressure that is exerted by a liquid within a closed system, such as blood as it presses against vessel membranes in response to pumping of the heart
The overall osmotic effect of colloids, such as plasma proteins, is called the ________________ or _______________.
oncotic pressure, colloid osmotic pressure
Oncotic pressure tends to pull water__________________
into the circulatory system
Albumin cannot move through normal capillary pores, while water and smaller structures can move freely. Na+ is highly attracted to albumin, thus, together they maintain __________________ by attracting water into the intravascular space.
oncotic pressure (or colloid osmotic pressure)
This pituitary hormone controls water reabsorption-has direct control over how much fluid is excreted in urine
ADH
This adrenal hormone controls Na+ absorption and plays a major role in Na+ balance and volume
aldosterone
Aldosterone is stimulated by:
a decreased Na+ volume to the kidneys
This hormone is in charge of Na+ excretion
naturietic hormone
This hormone controls Ca++ levels
PTH
What is the function of erythropoietin?
triggered by decreased oxygen delivery in the kidneys, stimulates bone morrow to produce RBC’s in response to tissue hypoxia
List the steps that occur in the renin-angiotensin response
START: angiotensinogen circulates in blood stream ->Renin secreted by kidneys in response to low blood pressure -> renin converts angiotensinogen into Angiotensin I -> Enzyme in lungs -> Angiotensin II -> (2 effects) 1. aldosterone secretion stimulated =increased Na+ and water retention 2. vascular smooth muscle constricts
What is the goal of the renin-angiotensin response?
To increase blood volume, thus, increasing blood pressure
Kidney function is totally dependent on:
blood flow
What is the normal level for Cl?
95-104 mEq
What is the normal value for HCO3?
22-26
What is the normal serum Ca level?
8 to 10
What is the normal value of P?
2 to 4
What is the normal value of Mg?
1.5-2 mEq
What is a normal BUN?
10 to 20
What is a normal creatinine?
.5-1
What is a normal Osm?
280-300 mOsm/dl
What is a normal specific gravity?
1.0010-1.0020-the higher the #, the more diluted the urine
What is an absolute minimum urine output?
20-30 ml/hr
What are 2 examples of fluid status indicators one could sue during a physical exam?
mucous membranes, turgor
What is a fluid status indicator that could be used in a blood test?
hemotocrit
A BUN test measures:
plasma-a direct measure of kidney finction.
A high BUN indicates:
the kidneys are not concentrating urine
Fluid status indicators in urine include:
output (volume), specific gravity (concentration), electrolytes (Na+, K+)
Observable manifestations of fluid status may include:
Drop in urine output, dyspnea, hypertension, hypotension, shock, hemodilution, hemoconcentration
Excess fluid volume in intravascular compartment is known as:
hypervolemia
Excess interstitial fluid is called:
edema
Excess fluid inside cells is called:
Intracellular (IC) swelling
IC swelling can cause
hypoxia
Impeding movement between vascular & interstitial space, decrease in capillary flow d/t increase tissue pressure, and interference w/ organ function are all complications due to:
edema
Define interstitial edema(3rd spacing):
increase in filtration and/or decrease in reabsorption due to altered capillary forces
What are the 4 mechanisms of 3rd spacing(interstitial edema)?know for test
massive inflammation, venous obstruction, increased blood volume, low serum albumin
T or F: 3rd spacing is always due to a fluid excess in the body.
FALSE-a distribution problem, not necessarily related to amount of fluid in the body
3rd spacing can effect what regions inside the body?
interstitial spaces (edema) or potential spaces (effusion) ex: in heart, lungs, joint cavities, chest cavity
Dyspnea, crackles, decreased urine output, irregular RR, HR, BP, and peripheral edema are all signs of:
congestive heart failure
A decreased blood volume capable of causing hypotension, tachycardia, and decreased urine output is:
hypovolemia
