Body Water, Osmolarity Physiology and Fluid Replacement Products Flashcards
Things to administer before administration?
6
- Things to consider before administration
- Body fluid compartments
- ECF, ICF - Fluid replacement products
- Crystalloids, colloids
- Isotonic, hypotonic, hypertonic - Volume
- Electrolytes
- Maintenance therapy
Fluid and electrolyte disorders in a surgical patient
- Disorders of volume? 2
- Disorders of the electrolyte concentrations? 6
- Disorders of volume
- Depletion
- Excess - Disorders of electrolyte concentrations
- Sodium
- Potassium
- Chloride
- Calcium
- Magnesium
- Phosphate
Sequelae of inappropriate fluid and electrolyte management
8
- Increased length of stay
- Increased cost
- Wound infection
- Delayed wound healing
- Anastomotic failure
- Tachyarrhythmias
- Cerebral edema, seizures, death
- Pulmonary edema, CHF, renal failure
What are you trying to accomplish with IV fluids?
- What is maintance therapy?
- Replacement therapy?
- Volume resuscitation?
- Maintenance therapy
- If the patient is not expected to eat or drink for a period of time - Replacement therapy
- Correct abnormalities in volume and/or electrolytes - Volume resuscitation
- Hypotension, hemorrhage
Total body water is directly related to what?
and Inversely proportional to what?
- Directly proportional to the muscle mass
- Muscle mass is about 70% water - Inversely proportional to fat
Fat is about 10% water
Total body water percentage:
- Neonates?
- Young healthy fit male?
- Young healthy fit female?
- Total body water as a % of weight decreases in who? 3
- Neonates
- 75-80% of body weight is water - Young healthy fit male
- On average 60% of his body weight is water - Young healthy fit female
- On average 55% of her body weight is water - Total body water as a % of weight decreases in:
- Morbidly obese,
- elderly, or
- low muscle mass due to disease or injury
May be as little as 35%
Total body water consists of two main compartments
- What are they?
- What part of TBW do they make up?
- How many liters each?
- Intracellular fluid
- 2/3 of TBW
- 28L (70kg man)
- Extracellular fluid
- 1/3 of TBW
- 14L (70kg man)
- What makes up the extracellular volume? 2
- Plasma and Interstitial space
- What is the main cation in plasma?
- Others that are there?
- Anions? 5
- What is different about interstitial space in the ECF than plasma?
Plasma
- Na+ is the main cation
- Other cations:
- K+,
- Ca++,
- Mg++ - Anions:
- Cl-,
- HCO3-,
- proteins,
- sulfates,
- organic acids - Interstitial space
- Same as plasma but lower concentration of protein
What are the main cations in the intracellular space? 2
Main anions are? 3
- K+ and
- Mg++ are the main cations
Main anions are
- phosphates,
- sulfates and
- proteins
Diffusion of proteins and ions is limited
- _____ diffusion is limited
- Sodium stays mainly on the ________ of the cell
- Potassium stays mainly on the _______ of the cell
- Water may diffuse how?
- Free
- outside
- inside
- freely among all compartments
- Movement of water is considered?
- Exchange of water between the intracellular and interstitial compartments is determined by what?
- ECF hypo-osmolar = water will go into cells where the osmolarity is ________ until equilibrium is reached
- Passive
- osmotic gradients
- higher
Osmolarity
1. Normal body fluid osmolarity about _____ osmol/L
- Hyperosmolarity will occur in both the ECF and ICF if what is increased?
- Fluid will move from the ICF to the ECF and leave the ICF more concentrated from loss of water therefore = what?
- 285
- extracellular osmolarity
- hyperosmolar
Summary of Body Fluid Compartments
1. What is ICF and what percentage does it make up total body fluid?
- What is ECF and what percentage does it make up total body fluid?
- What are the two componenets of the ECF and where are they?
- Intracellular fluid (ICF)
- Fluid within cells
- 2/3 of body fluid is ICF - Extracellular fluid (ECF)
- Fluid outside of cells
- 1/3 of body fluid - Two components
- Interstitial fluid – fluid surrounding cells (26% of ECF)
- Vascular space – fluid within blood vessels (7% plasma, blood)
Fluid Replacement Products
2
Then can further categorize into what? 3
- Crystalloids
- Colloids
Then can be further categorized as
- Isotonic
- Hypotonic
- Hypertonic
What are the categories of crystalloids? 4
- Dextrose in water
- Saline
- Combo
- Ringer’s lactate
What are the categories of Colloids?
5
- Albumin
- Dextran
- Hetastarch
- Blood
- Fresh frozen plasma
Name the following fluids in each crystalloid category:
- Dextrose in water? 3
- Saline? 3
- Combo? 3
- Ringer’s lactate (whats in it 4)?
- Dextrose in water
- D5W
- D10W
- D50W - Saline
- Isotonic (0.9% or “normal”)
- Hypotonic (0.45%, 0.225%)
- Hypertonic (3%, 5%) - Combo
- D5 1/2NS
- D5 NS
- D10 NS - Ringer’s lactate “physiologic”.
(K, HCO3, Mg, Ca)
What are the two albumin concentrations?
- 5% in NS
2. 25% (Salt Poor)
- What are crystalloids?
2. How does the solution transfer?
- Solutions that contain small molecules and are able to pass through semipermeable membranes
- Solution transfers easily across the cell membrane of the blood vessels (small particles)
- What are colloids?
2. Describe their permeability?
- Solutions that contain high molecular weight proteins (like albumin) or starch
- Do not cross the capillary semipermeable membrane
- Remain in the intravascular space (pulling fluid out of the intracellular and interstitial space) for several days
- When are crystalloids used most?
2. Colloids?
- Crystalloids are generally adequate for most situations needing fluid management
- Colloids may be indicated when more rapid hemodynamic equilibration is required
- Isotonic solutions are used for?
- Hypotonic solutions are used for?
- Hypertonic?
- Isotonic solutions
- given to expand the ECF volume - Hypotonic solutions
- given to reverse dehydration - Hypertonic solutions
- given to increase the ECF volume and decrease cellular swelling
- Isotonic fluids have the same osmolality as plasma, so the fluids remain primarily in the where?
- Isotonic IV fluids are used to do what? 2
- ECF
- replace ECF losses and
- to expand vascular volume quickly
What are the isotonic solutions?
3
- Normal saline (NS, 0.9% NaCl)
- Ringer’s solution
- Lactated Ringer’s (RS)
What do the following conatin?
- Normal saline (NS, 0.9% NaCl) 2
- Ringer’s solution 3
- Lactated Ringer’s (RS) 5
What do they not have?
- Normal saline (NS, 0.9% NaCl) 2
- Ringer’s solution 5
- Lactated Ringer’s (RS) 3
Normal Saline (NS, 0.9% NaCl) 1. provides
- sodium and
- chloride in water with same osmolality as serum;
2. Ringer’s solution – contains - sodium,
- potassium,
- calcium in similar concentrations to plasma
3. Lactated Ringer’s (LR) – contains - sodium,
- chloride,
- potassium,
- calcium, and
- lactate in concentrations similar to normal plasma
- Normal Saline (NS, 0.9% NaCl)
- no calories or
- free water (water without solute) - Ringer’s solution
- no dextrose,
- magnesium or
- bicarbonate;
- no calories or
- free water - Lactated Ringer’s (LR) –
- no dextrose,
- magnesium or
- free water
Hypotonic solutions
1. _______ osmolality than normal plasma
- MOA?
- What does this result in? 2
- Used for? How?
- Contraindicated in? Why?
- Lower
- Increases cell water by pulling water out of the vessels into the cells
- Results in
- decreased vascular volume and
- increased cell water - Used to prevent and treat cellular dehydration by providing free water to the cells
- CONTRAINDICATED in acute brain injuries because cerebral cells are very sensitive to free water, absorbing it rapidly and leading to cerebral cellular edema
What are our hypotonic solutions?
3
- 5% Dextrose in water (D5W)
- 0.45% normal saline (1/2 NS)
- 0.225% normal saline (1/4 NS)
5% dextrose in water (D5W) –
- Describe the difference between D5W in a bag and then when it gets into the body?
- What can it prevent?
- 45% saline (1/2 NS) and 0.225 saline (1/4 NS) –
- What do they provide the cells and what are they often used as?
5% dextrose in water (D5W) –
1. although isotonic in IV bag, it has a hypotonic effect in the body as the dextrose is quickly metabolized…leaving free water that shifts osmosis from vessels into cells;
- the dextrose content does not meet daily nutritional caloric requirements but it does prevent starvation
- 45% saline (1/2 NS) and 0.225 saline (1/4 NS) –
- these fluids provide free water to the cells as well as small amounts of sodium and chloride…
- often used as maintenance fluids
Hypertonic Fluids:
1. ________ osmolality than normal plasma
- Causes water to be pulled from the cells into the ________?
- resulting in what? 2
- Higher
- vessels
- increased vascular volume
- decreased cell water
Hypertonic Solutions
Used to treat very specific problems
-Administered in carefully controlled, limited doses to avoid what?
2
- vascular volume overload
2. and cell dehydration…pulls excess fluid from cells and to promote osmotic diuresis
Hypertonic Fluids
What is the one?
Saline solutions > 0.9%
Used infrequently
Describe movement in the following solutions:
- Isotonic?
- Hypotonic?
- Hypertonic?
- Stays inside the bloodstream or intravascular compartment
- Will shift and flow into a more concentrated solution
(draws fluid from vessels and moves fluid into cells) - Will pull a less concentrated solution into itself
(draws fluid out of the cells and into the blood) ex: tx severe low Na levels
- D5W is handled like free water since dextrose is what?
2. with high volumes infusion there is a risk for which electrolyte disturbance?
- metabolized
2. Hyponatremia
- 0.9% saline (isotonic) does not diffuse thru all compartments since what?
- ½ NS…1/2 behaves as what and ½ as what?
- the cell membrane is impermeable to sodium
2. free water, saline
1 Liter 0.9% saline (isotonic…distributed in _____ since cell membrane not permeable to sodium)
ECF
-does not go into ICF
1 liter 5% Albumin and PRBCs (remains in where?)
intravascular space
Adverse affects of the following are:
- Normal saline? 3
- Lactated ringers? 3
- D5W? 1
- Normal saline
- Fluid overload
- Metabolic acidosis (hyperchloremic)
- Hypernatremia - Lactated Ringers
- Fluid overload
- Hyponatremia
- Hyperkalemia - D5W
- Hyponatremia
