Fluid & Electrolytes Part 1 Flashcards
Total Body Fluid =
60 % of Adult’s Total Body Weight (TBW)
Intracellular Fluid (ICF) makes up how much of the body’s TBW?
40% of TBW
Extracellular Fluid (ECF) makes up how much of the body’s TBW?
20% of TBW
ICF is where in the body?
ECF is where in the body?
ICF = Inside the cells
ECF = Anywhere outside of the cells
Extracellular Fluid is divided into-
Interstitial Fluid
Plasma (Intravascular)
Transcellular
Interstitial fluid makes up what % of ECF?
15% of ECF
Fluid in the spaces between the cells =
Interstitial Fluid
Cushions the cells + Helps with cell transport =
Intracellular Fluid
Plasma is -
Intravascular
Plasma is fluid within-
The blood vessel
Plasma makes up what % of ECF?
4% of ECF
Transcellular fluid makes up what % of ECF?
1% of ECF
Plasma is what part of the blood?
The liquid part of the blood
Blood cells (Platelets, WBC’s, and RBC’s) are all suspended in-
Plasma
Transcellular is fluid found in-
Body Cavities
Places Transcellular Fluid can be found in body cavities like-
Cerebrospinal Fluid, GI Tract, Pleural Cavity (a cavity in the lungs), or the Pericardial Space
% of TBW that is water:
Preterm =
~80% of TBW is water
A Preterm is a-
Baby born before the 37 weeks of pregnancy are completed
A Neonate is a baby under-
4 weeks old
% of TBW that is water:
Neonate =
~74 %
The TBW that’s water or Total Body Water decreases as you-
Age
The % of Total Body Water for a child is-
~ 60%
The average Total Body Water for an adult is -
~60 %
The average Total Body Water for an older adult is -
~ 40% - 50%
The highest amounts of Total Body Water is found in-
Preterms + Neonates (~70% - 80%)
The lowest amounts of Total Body Water is found in-
Older Adults (~40% - 50%)
Why do neonates + preterms have so much body water?
It helps to cushion + protect.
Metabolism is increased with rapid growth.
There is an exchange of nutrients and wastes going on.
Kidneys are immature, so they excrete more water than an adult does.
There is an immature regulatory response that responds to illnesses with higher temps + longer durations.
Implications for children =
Their Daily Fluid Requirements are higher than an adults.
They have very little extra fluid to handle extra fluid loss. (Meaning that diarrhea, fever, and vomiting can all easily cause dehydration)
Why is there less Total Body Water in an older adult?
They have more cell death (apoptosis), they have less need for intracellular fluid, their metabolism is slowed, they have more body fat
Fat cells have less-
Water
Implications for adults:
Daily requirement of water is 40mL/kg per day. This makes people who are obese, women, or are an older adult at higher risk for fluid volume deficit / dehydration.
K+ =
Potassium
Na+ =
Sodium
Ca+ =
Calcium
Body water contains-
Electrolytes
Potassium, Sodium, Magnesium, and Calcium are all-
Electrolytes
Sodium helps to regulate the-
Body-Water Balance
Potassium Works with-
Muscle Function
Electrolytes maintain function of-
Body Systems
Electrolytes are what?
Molecules that disassociate (separate) in the fluid into electrically charged ions
Ions are-
Electrically charged particles
Cations have a -
Positive (+) Charge
Anions have a-
Negative (-) Charge
Is sodium positive or negative?
Positive
Cations have a current that-
Maintains cell function
Potassium is a major cation that maintains cell functioning in what way?
Effects your cardiac system.
If potassium gets out of whack, what occurs?
Dysrhythmias
mEq/L stands for=
Milliequivialent
mEq/L is a measurement for-
Electrolytes
Milliequivalence refers to-
the combining power of the ion
Sodium + Chloride are -
Equivalent
Why are Sodium + Chloride equivalent?
They combine equally
Primary intracellular cation =
Potassium (K+)
Primary Intracellular Anion =
Phosphate (PO^4-)
Primary Extracellular Cation =
Sodium (Na+)
Primary Extracellular Anion =
Chloride (Cl-)
You need an equal number of (+) and (-) for -
The Electrolyte Balance
Difference between the number of (+) and (-) =
Anion Gap
The Anion Gap is a kind of-
Lab Value
When viewing the Anion Gap, abnormal amounts of cations + anions means that there’s-
An Abnormal Electrical Charge
Hypokalemia or hyperkalemia, and other electrolyte imbalances are examples of-
An Abnormal Electrical Charge
Substance/ particle/ molecule that dissolves in liquid, such as water or IVF =
Solute
A type of solute that easily dissolves in solution =
Crystalloids
Sugar crystals dissolve easily in coffee, these are an example of-
Crystalloids
Electrolytes easily metabolize in -
Body Fluid
A type of solute that is a large particle and doesn’t dissolve easily =
Colloids
Electrolytes, Glucose, Protein (Albumin + Globulin) , Gases (Oxygen + Carbon Dioxide) , and Molecules are all-
Solutes
Solvent =
The thing doing the dissolving
Plasma Proteins (Albumin + Globulin) are what kind of solute?
Colloids
Colloids act as magnets that pull water towards themselves.
True or false?
True
Colloids are also called -
Blood Proteins or Serum Colloids
Act as a magnet that creates osmotic pressure =
Colloids
Osmotic Pressure is the-
Osmotic pull that “pulls” water to a colloid
In Diffusion, what’s moving?
Molecules
In diffusion, molecules are-
Solutes
In Diffusion, molecules move from an area of -
High concentration to an area of low concentration
Movement of solutes stop whenever the concentration of molecules is-
Equal on both sides (Equilibrium is reached between molecules)
In Osmosis, what’s moving?
The water
Water moves based on the-
Concentration of a solution
Water moves from an area of
Lower concentration to an area of high concentration of solutes across a semi-permeable membrane
What does osmosis cause?
Equal concentration of solution on both sides of a membrane
Power of solution to pull water across a semipermeable membrane =
Osmotic Pressure
A solution with more solutes has a greater -
Osmotic Pressure
Power of solution =
Osmotic Pressure
Strength of the “pull” or “draw” that depends on the number of solutes =
Osmotic Pressure
High Solute Concentration =
High Osmotic Pressure
High Osmotic Pressure =
Pulls water towards itself
The concentration of solutes is expressed as -
Osmolality
If something has a high Osmolality then it has-
A lot of solutes
If something has a low Osmolality then it has-
A low amount of solutes
Measures the number of milliosmoles per kg (mOsm/kg) of water or the concentration of molecules per weight of water =
Osmolality
Measures the total number of milliosmoles per liter (mOsm/L) of solution or the concentration of molecules per volume of solution =
Osmolarity
Measurement of solutes/kg in water =
Osmolality
mOsm/kg =
Osmolality
The normal serum osmolality is -
280-295 mOsm/kg
The solute that’s the biggest determinant of Serum Osmolality =
Sodium
Normal Serum Osmolarity is-
275-295 mOsm/kg
Measures the osmotic pressure of a solution =
Osmolarity
Serum Osmolarity is a lab measure that reflects-
Solute concentration in blood, urine, or other body fluids.
Total solute concentration in body fluids.
A serum osmolarity under 275 means that-
There’s too little solute for the amount of water OR there’s too much water for the amount of solute (water excess)
(To simplify, there’s not enough solute)
A serum osmolarity over 295 means that-
There’s too little water (a water deficit) OR the concentration of solute is too great
(To simplify, there’s not enough water)
Serum Osmolality is just a fancy word for-
Osmolarity
Serum Osmolality and Osmolality mean the same thing.
True or false?
False.
Serum Osmolality = Osmolarity
A Serum Osmolality of 288 mOsm/kg is what type of Osmolality?
Iso-Osmolality
A Serum Osmolality of 310 mOsm/kg is what type of Osmolality?
Hyper-Osmolality
A Serum Osmolality of 269 mOsm/kg is what type of Osmolality?
Hypo-Osmolarity
Water Deficit =
Hyper-Osmolality (Hypertonic)
Water Excess =
Hypo-Osmolality (Hypotonic)
Same Osmolality as inside cells (ICF) and outside the cells (ECF) =
Isotonic Solution
Equal concentration of solutes and water =
Isotonic Solution
Why is there no fluid shift in an isotonic solution?
Because everything is already equal, there’s nothing to correct.
Low solute concentration =
Hypotonic Solution
In a hypotonic solution, the cell is surrounded by hypotonic water and what does that water do?
It enters the cell until it bursts
In a hypertonic solution, the cell is surrounded by hypertonic water and what does that water do?
The cell’s water leaves the cell to dilute the Extracellular fluid. This causes it to shrink.
Isotonic IV Fluids (IVF) has the same concentration as-
Extracellular Fluid (ECF)
An isotonic IVF causes what change in cell size?
No change in cell size
0.9% NaCl is a-
Isotonic IVF
Normal Saline / NS / Sodium Chloride
All of these are just different names for-
0.9% NaCl
5% Dextrose Water (D5W) is -
Isotonic, then hypotonic as dextrose quickly metabolizes
5% Dextrose Water (D5W) is a good-
Hydrating Solution
Lactated Ringer’s =
Isotonic IVF
Balanced Electrolytes. Used a lot in surgery with fluid / blood loss =
Lactated Ringer’s (LR)
Hypertonic IVF is more concentrated than-
ECF
Hypertonic IVF causes fluid to shift from-
Inside the cells to outside the cells
Hypertonic IVF causes ICF to go to -
Interstitial fluid, then possibly into intravascular
OR
Directly into intravascular, if a blood cell
Used to decrease cell edema or replace electrolytes =
Hypertonic IVF
5% Dextrose in Normal Saline (D5NS) =
Hypertonic IVF
5% Dextrose in 0.45% Normal Saline (D5 1/2NS) =
Hypertonic IVF
5% Dextrose in Lactated Ringer’s (D5LR) =
Hypertonic IVF
Hypotonic ICF is less concentrated that-
ECF
Solution is pulled into cell + causes cells to swell =
Hypotonic IVF
Hypotonic IVF causes a fluid shift from ECF (Intravascular, Interstitial) into-
The cell (ICF)
Used to dilute ECF + treat cellular dehydration =
Hypotonic IVF
0.45% NaCl (1/2 Normal Saline) =
Hypotonic IVF
0.33% NaCl (1/3 Normal Saline) =
Hypotonic IVF
Movement of water AND solutes together across capillary bed =
Filtration
Filtration causes water and solutes to move from -
High pressure to low pressure
There is how many types of pressure?
2
What are the 2 types of pressure?
Oncotic + Hydrostatic
Oncotic Pressure =
Colloid Osmotic Pressure
Osmotic “Pull” =
Colloid Osmotic Pressure
Amount of pressure from plasma colloids in vascular system =
Oncotic Pressure
Colloids exert what?
“Pull” that attracts water
Oncotic pressure pulls fluid from -
Tissue space to vascular space
Does Oncotic pressure stay constant throughout the blood vessel?
Yes
Force of fluid that presses against a vessel wall =
Hydrostatic Pressure
The force of hydrostatic pressure is greater at-
The arterial end of a vessel than at the venous end
Hydrostatic pressure is greater at which end?
It’d greater at the arterial end of the vessel than the venous end
Oncotic Pressure (Colloid Osmotic Pressure) stays-
Constant in the vascular space
Hydrostatic pressure at which end overrides colloid osmotic pressure?
The Arterial End
At the venous end, -
Oncotic pressure is greater than the hydrostatic pressure
Colloid osmotic pressure is able to “pull” -
Fluid + electrolytes back into the vessel from tissue spaces
What’s the result of osmotic pressure at the venous end?
Waste products of cell metabolism “pulled” back into vessel.
Wastes can get excreted via circulatory system.
Maintains healthy cells; no destruction of tissue cells; no edema.
What’s the result of hydrostatic pressure at the arterial end overriding osmotic pressure?
Hydrostatic pressure “pushes” fluid out of the vessel (Intravascular space) to interstitial (tissue) spaces.
Tissue cells get nourished with nutrients + oxygen.
Average Daily Fluid Requirements:
Average Adult = How many ml/day?
~2,000 - 3,000 ml/day
Average Daily Fluid Requirements:
Average Adult = How many ml/kg/day?
~ 40 ml/kg/day
Average Daily Fluid Requirements:
Infant / Child = how many ml/day?
~1,150 ml/day
Average Daily Fluid Requirements:
Infant / Child = how many ml/kg/day?
~100 - 150 ml/kg/day
Sources per day:
Oral Liquids =
~ 1,200 ml
Sources per day:
Water in Foods =
~1,000 ml
Sources per day:
Metabolism =
~ 300 ml (H20 from oxidation)
Primary regulator for fluid intake =
Thirst
Osmoreceptors are stimulated by -
Volume Depletion
When Osmoreceptors are stimulated by volume depletion, what happens?
You feel thirsty
Who’s at risk for dehydration because of a decreased thirst sensation?
Older adults
Why are infants at risk for dehydration?
Because they can’t communicate that they are thirsty
When water is absorbed in the GI tract, name 2 things that happen:
Volume of Extracellular fluid increases.
Osmolality of Extracellular fluid decreases.
Average daily fluid output=
~2,500 ml/day
Fluid Output
Sources/day:
Kidneys (Urine) =
1,500 ml
Fluid Output
Sources/day:
Skin =
300 ml
Fluid Output
Sources/day:
GI (Fecal) =
100 ml
Insensible Fluid Losses =
Not Measurable
Skin via Diffusion =
Insensible Fluid Losses
Lungs via Exhalation =
Insensible Fluid Losses
Sensible Fluid Losses =
Measurable Fluid Losses
Name some examples of sensible fluid losses:
Urine; Feces; Vomiting; Excess Perspiration
What kind of patient’s would you not want to give LR to?
To PT’s with liver impairment (Cirrhosis or Hepatitis are examples)
Why can’t you give LR to PT’s with liver impairment (Cirrhosis or Hepatitis)?
Their body can’t process Lactate correctly
