IV Fluids

Question 1

What is diffusion?

Answer 1

Movement of SOLUTE from high concentration to low concentration

Question 2

What feature must the membrane have for diffusion?

Answer 2

Must be solute permeable

Question 3

What is osmosis?

Answer 3

Movement of water from high concentration to low concentration

Question 4

What feature must the membrane have for osmosis?

Answer 4

Solute impermeable

Question 5

What is osmolarity?

Answer 5

The measure of the solute concentration per unit VOLUME of solute

Question 6

What does osmolarity take into account?

Answer 6

ALL of the solute concentrations, not just the ones that cant cross the semipermeable membrane

Question 7

What would be the concentrations of H20 and solute be in the hyperosmotic side?

Answer 7

Higher solute concentration

Lower free H20 concentration

Question 8

What concentrations of H20 and solute be in the hypoosmotic side?

Answer 8

Lower solute concentration

higher free H20 concentration

Question 9

What is osmolality?

Answer 9

Measure of solute concentration per unit MASS of solvent

Question 10

Osmolality in the ICF and ECF

Answer 10

It is the same in the ICF and ECF

Question 11

What is tonicity?

Answer 11

The measure of the osmotic pressure gradient between two solutions

Question 12

What is tonicity influenced by?

Answer 12

Only influenced by solutes that cannot cross the semipermeable membrane, because these are the solutes influencing the osmotic pressure gradient

Question 13

How much water is in the body of a average 70kg male?

Answer 13

42 litres

Question 14

Distribution of water in the body

Answer 14

42 L in total 
2/3 (28L) INTRACELLULAR
- 66%
1/3 (14L) EXTRACELLULAR 
- 20% plasma (3L)
- 80% interstitial

Question 15

How much water is needed per day?

Answer 15

25 - 30 ml / kg/ day

Question 16

How much sodium is needed per day?

Answer 16

1 mmol / kg / day

Question 17

How much potassium is needed per day?

Answer 17

1 mmol / kg / day

Question 18

How much glucose is needed per day?

Answer 18

50-100g / day

Question 19

How much of fat is water?

Answer 19

10%

Question 20

How much of muscle is water?

Answer 20

75%

Question 21

How much does our water content change with age?

Answer 21

Babies = 70%
Child = 60%
Old person = 50%

Question 22

Questions to ask about fluids

Answer 22

1. What is my patients volume status?
2. Does my patient need IV fluids?
3. How much fluid do they need?
4. What types of fluid do they need?

Question 23

What is euvolaemia?

Answer 23

The right amount of fluid in the body

Question 24

Presentation of euvolaemia

Answer 24

Feels well 
Not thirsty
Veins well filled
Warm extremities 
Mild sweat 
Normal BP and HR
Normal urine

Question 25

Needs of euvolaemia

Answer 25

No fluids (unless electrolyte deplete or low BP)

Question 26

Presentation of hypovolaemia

Answer 26

``` nausea thirsty flat veins cool peripheries no sweat low or postural BP and high HR Concentrate oliguria Responds to SLR ```

Question 27

Needs of hypovolaemia

Answer 27

Resuscitation fluids (if low BP) Rehydration fluids "plug the leak"

Question 28

Presentation of hypervolaemia

Answer 28

``` Feels breathless Not thirsty Veins distended Warm and oedematous extremities sweaty high BP and high HR Dilute urine (could be oliguric or polyruic) ```

Question 29

Needs of hypervolaemia

Answer 29

No more fluids Possibly diuretics (if resp compromise) Hemofiltration (if anuric)

Question 30

Low oncotic pressure (low protein/albumin) can present as what?

Answer 30

Oedema in dehydrated patients due to loss of intracapillary fluid Tends to be odematous, but behave hypovolaemic (low BP, high HR, thirsty)

Question 31

What can heart failure present as?

Answer 31

Oedema Low BP but still require diuresis due to high circulating volume causing increased RVP

Question 32

Things to look at to work out the water deficit

Answer 32

``` Catheters Drains Input charts Vomit bowels Sputum pots Stool charts and stoma losses ```

Question 33

What are the insensibles?

Answer 33

Transepidermal diffusion Open wounds Burns Bleeding

Question 34

What is Transepidermal diffusion?

Answer 34

Water that passes through the skin and is lost by evaporation AND water loss from the resp tract. Sepsis (sweat) ventilation

Question 35

How much loss of fluid occurs daily in adults by Transepidermal diffusion?

Answer 35

400-800mls

Question 36

The 5 Rs

Answer 36

``` Resuscitation Routine maintenance Replacement Redistribution Reassessment ```

Question 37

What are IV fluids used?

Answer 37

If cannot take orally Urgently to restore circulation with hypovolaemia Enterally to meet patient maintenance requirements

Question 38

If dont need IV fluids for resuscitation, when is another scenario you may need for IV fluids?

Answer 38

If need IV additional to maintenance to correct existing deficit OR ongoing abnormal external losses e.g. diarrhoea, fever

Question 39

Where can dextrose move in the body?

Answer 39

Through all compartments

Question 40

Dextrose is useful in …..

Answer 40

Chronic dehydration | Hypernatraemia

Question 41

When is dextrose not useful?

Answer 41

Resuscitation | Low albumin

Question 42

Where do crystalloids remain?

Answer 42

In ECF

Question 43

Crystalloids are useful in …..

Answer 43

Acute dehydration AKI resuscitation

Question 44

When are crystalloids not useful?

Answer 44

Long term maintenance | Hypernaetraemic patient

Question 45

Plasma expanders are useful in …..

Answer 45

liver patients | select intra-operative

Question 46

What are plasma expanders not useful in?

Answer 46

much else

Question 47

What are plasma expanders and where are they found in the body?

Answer 47

Colloids | Exclusively stay in IVS