Body Water, Osmolarity Physiology and Fluid Replacement Products

Question 1

Things to administer before administration?

6

Answer 1

1. Things to consider before administration
2. Body fluid compartments
   - ECF, ICF
3. Fluid replacement products
   - Crystalloids, colloids
   - Isotonic, hypotonic, hypertonic
4. Volume
5. Electrolytes
6. Maintenance therapy

Question 2

Fluid and electrolyte disorders in a surgical patient

1. Disorders of volume? 2
2. Disorders of the electrolyte concentrations? 6

Answer 2

1. Disorders of volume
   - Depletion
   - Excess
2. Disorders of electrolyte concentrations
   - Sodium
   - Potassium
   - Chloride
   - Calcium
   - Magnesium
   - Phosphate

Question 3

Sequelae of inappropriate fluid and electrolyte management

8

Answer 3

1. Increased length of stay
2. Increased cost
3. Wound infection
4. Delayed wound healing
5. Anastomotic failure
6. Tachyarrhythmias
7. Cerebral edema, seizures, death
8. Pulmonary edema, CHF, renal failure

Question 4

What are you trying to accomplish with IV fluids?

1. What is maintance therapy?
2. Replacement therapy?
3. Volume resuscitation?

Answer 4

1. Maintenance therapy
   - If the patient is not expected to eat or drink for a period of time
2. Replacement therapy
   - Correct abnormalities in volume and/or electrolytes
3. Volume resuscitation
   - Hypotension, hemorrhage

Question 5

Total body water is directly related to what?

and Inversely proportional to what?

Answer 5

1. Directly proportional to the muscle mass
   - Muscle mass is about 70% water
2. Inversely proportional to fat
   Fat is about 10% water

Question 6

Total body water percentage:

1. Neonates?
2. Young healthy fit male?
3. Young healthy fit female?
4. Total body water as a % of weight decreases in who? 3

Answer 6

1. Neonates
   - 75-80% of body weight is water
2. Young healthy fit male
   - On average 60% of his body weight is water
3. Young healthy fit female
   - On average 55% of her body weight is water
4. Total body water as a % of weight decreases in:
5. Morbidly obese,
6. elderly, or
7. low muscle mass due to disease or injury

May be as little as 35%

Question 7

Total body water consists of two main compartments

1. What are they?
2. What part of TBW do they make up?
3. How many liters each?

Answer 7

1. Intracellular fluid
2. 2/3 of TBW
3. 28L (70kg man)
4. Extracellular fluid
5. 1/3 of TBW
6. 14L (70kg man)

Question 8

1. What makes up the extracellular volume? 2

Answer 8

1. Plasma and Interstitial space

Question 9

1. What is the main cation in plasma?
2. Others that are there?
3. Anions? 5
4. What is different about interstitial space in the ECF than plasma?

Answer 9

Plasma

1. Na+ is the main cation
2. Other cations:
   - K+,
   - Ca++,
   - Mg++
3. Anions:
   - Cl-,
   - HCO3-,
   - proteins,
   - sulfates,
   - organic acids
4. Interstitial space
   - Same as plasma but lower concentration of protein

Question 10

What are the main cations in the intracellular space? 2

Main anions are? 3

Answer 10

1. K+ and
2. Mg++ are the main cations

Main anions are

1. phosphates,
2. sulfates and
3. proteins

Question 11

Diffusion of proteins and ions is limited

1. _____ diffusion is limited
2. Sodium stays mainly on the ________ of the cell
3. Potassium stays mainly on the _______ of the cell
4. Water may diffuse how?

Answer 11

1. Free
2. outside
3. inside
4. freely among all compartments

Question 12

1. Movement of water is considered?
2. Exchange of water between the intracellular and interstitial compartments is determined by what?
3. ECF hypo-osmolar = water will go into cells where the osmolarity is ________ until equilibrium is reached

Answer 12

1. Passive
2. osmotic gradients
3. higher

Question 13

Osmolarity
1. Normal body fluid osmolarity about _____ osmol/L

2. Hyperosmolarity will occur in both the ECF and ICF if what is increased?
3. Fluid will move from the ICF to the ECF and leave the ICF more concentrated from loss of water therefore = what?

Answer 13

1. 285
2. extracellular osmolarity
3. hyperosmolar

Question 14

Summary of Body Fluid Compartments
1. What is ICF and what percentage does it make up total body fluid?

2. What is ECF and what percentage does it make up total body fluid?
3. What are the two componenets of the ECF and where are they?

Answer 14

1. Intracellular fluid (ICF)
   - Fluid within cells
   - 2/3 of body fluid is ICF
2. Extracellular fluid (ECF)
   - Fluid outside of cells
   - 1/3 of body fluid
3. Two components
   - Interstitial fluid – fluid surrounding cells (26% of ECF)
   - Vascular space – fluid within blood vessels (7% plasma, blood)

Question 15

Fluid Replacement Products
2

Then can further categorize into what? 3

Answer 15

1. Crystalloids
2. Colloids

Then can be further categorized as

1. Isotonic
2. Hypotonic
3. Hypertonic

Question 16

What are the categories of crystalloids? 4

Answer 16

1. Dextrose in water
2. Saline
3. Combo
4. Ringer’s lactate

Question 17

What are the categories of Colloids?

5

Answer 17

1. Albumin
2. Dextran
3. Hetastarch
4. Blood
5. Fresh frozen plasma

Question 18

Name the following fluids in each crystalloid category:

1. Dextrose in water? 3
2. Saline? 3
3. Combo? 3
4. Ringer’s lactate (whats in it 4)?

Answer 18

1. Dextrose in water
   - D5W
   - D10W
   - D50W
2. Saline
   - Isotonic (0.9% or “normal”)
   - Hypotonic (0.45%, 0.225%)
   - Hypertonic (3%, 5%)
3. Combo
   - D5 1/2NS
   - D5 NS
   - D10 NS
4. Ringer’s lactate “physiologic”.
   (K, HCO3, Mg, Ca)

Question 19

What are the two albumin concentrations?

Answer 19

1. 5% in NS

2. 25% (Salt Poor)

Question 20

1. What are crystalloids?

2. How does the solution transfer?

Answer 20

1. Solutions that contain small molecules and are able to pass through semipermeable membranes
2. Solution transfers easily across the cell membrane of the blood vessels (small particles)

Question 21

1. What are colloids?

2. Describe their permeability?

Answer 21

1. Solutions that contain high molecular weight proteins (like albumin) or starch
2. Do not cross the capillary semipermeable membrane
   - Remain in the intravascular space (pulling fluid out of the intracellular and interstitial space) for several days

Question 22

1. When are crystalloids used most?

2. Colloids?

Answer 22

1. Crystalloids are generally adequate for most situations needing fluid management
2. Colloids may be indicated when more rapid hemodynamic equilibration is required

Question 23

1. Isotonic solutions are used for?
2. Hypotonic solutions are used for?
3. Hypertonic?

Answer 23

1. Isotonic solutions
   - given to expand the ECF volume
2. Hypotonic solutions
   - given to reverse dehydration
3. Hypertonic solutions
   - given to increase the ECF volume and decrease cellular swelling

Question 24

1. Isotonic fluids have the same osmolality as plasma, so the fluids remain primarily in the where?
2. Isotonic IV fluids are used to do what? 2

Answer 24

1. ECF
2. • replace ECF losses and
   • to expand vascular volume quickly

Question 25

What are the isotonic solutions? | 3

Answer 25

1. Normal saline (NS, 0.9% NaCl) 2. Ringer's solution 3. Lactated Ringer's (RS)

Question 26

What do the following conatin? 1. Normal saline (NS, 0.9% NaCl) 2 2. Ringer's solution 3 3. Lactated Ringer's (RS) 5 What do they not have? 1. Normal saline (NS, 0.9% NaCl) 2 2. Ringer's solution 5 3. Lactated Ringer's (RS) 3

Answer 26

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 1. Normal Saline (NS, 0.9% NaCl) - no calories or - free water (water without solute) 2. Ringer’s solution - no dextrose, - magnesium or - bicarbonate; - no calories or - free water 3. Lactated Ringer’s (LR) – - no dextrose, - magnesium or - free water

Question 27

Hypotonic solutions 1. _______ osmolality than normal plasma 2. MOA? 3. What does this result in? 2 4. Used for? How? 5. Contraindicated in? Why?

Answer 27

1. Lower 2. Increases cell water by pulling water out of the vessels into the cells 3. Results in - decreased vascular volume and - increased cell water 4. Used to prevent and treat cellular dehydration by providing free water to the cells 5. CONTRAINDICATED in acute brain injuries because cerebral cells are very sensitive to free water, absorbing it rapidly and leading to cerebral cellular edema

Question 28

What are our hypotonic solutions? | 3

Answer 28

1. 5% Dextrose in water (D5W) 2. 0.45% normal saline (1/2 NS) 3. 0.225% normal saline (1/4 NS)

Question 29

5% dextrose in water (D5W) – 1. Describe the difference between D5W in a bag and then when it gets into the body? 2. What can it prevent? 0. 45% saline (1/2 NS) and 0.225 saline (1/4 NS) – 1. What do they provide the cells and what are they often used as?

Answer 29

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; 2. the dextrose content does not meet daily nutritional caloric requirements but it does prevent starvation 0. 45% saline (1/2 NS) and 0.225 saline (1/4 NS) – 1. these fluids provide free water to the cells as well as small amounts of sodium and chloride… 2. often used as maintenance fluids

Question 30

Hypertonic Fluids: 1. ________ osmolality than normal plasma 2. Causes water to be pulled from the cells into the ________? 3. resulting in what? 2

Answer 30

1. Higher 2. vessels 3. - increased vascular volume - decreased cell water

Question 31

Hypertonic Solutions Used to treat very specific problems -Administered in carefully controlled, limited doses to avoid what? 2

Answer 31

1. vascular volume overload | 2. and cell dehydration…pulls excess fluid from cells and to promote osmotic diuresis

Question 32

Hypertonic Fluids | What is the one?

Answer 32

Saline solutions > 0.9% | Used infrequently

Question 33

Describe movement in the following solutions: 1. Isotonic? 2. Hypotonic? 3. Hypertonic?

Answer 33

1. Stays inside the bloodstream or intravascular compartment 2. Will shift and flow into a more concentrated solution (draws fluid from vessels and moves fluid into cells) 3. Will pull a less concentrated solution into itself (draws fluid out of the cells and into the blood) ex: tx severe low Na levels

Question 34

1. D5W is handled like free water since dextrose is what? | 2. with high volumes infusion there is a risk for which electrolyte disturbance?

Answer 34

1. metabolized | 2. Hyponatremia

Question 35

1. 0.9% saline (isotonic) does not diffuse thru all compartments since what? 2. ½ NS…1/2 behaves as what and ½ as what?

Answer 35

1. the cell membrane is impermeable to sodium | 2. free water, saline

Question 36

1 Liter 0.9% saline (isotonic…distributed in _____ since cell membrane not permeable to sodium)

Answer 36

ECF | -does not go into ICF

Question 37

1 liter 5% Albumin and PRBCs (remains in where?)

Answer 37

intravascular space

Question 38

Adverse affects of the following are: 1. Normal saline? 3 2. Lactated ringers? 3 3. D5W? 1

Answer 38

1. Normal saline - Fluid overload - Metabolic acidosis (hyperchloremic) - Hypernatremia 2. Lactated Ringers - Fluid overload - Hyponatremia - Hyperkalemia 3. D5W - Hyponatremia