Perioperative Fluid Mx

Question 1

What is total body water

Answer 1

TBW 60% of body weight 70kg man - 42L

Question 2

What does total body water separate into what compartments

Answer 2

Intracellular fluid - 40% of that 28L and

Extra cellular fluid - 20% of that 14 L

Question 3

What doesECF separate into

Answer 3

Interstitial fluid 10L

Intravascular fluid -4L 60-70ml per kg

Question 4

What happens to body water as we age

Answer 4

Decreases

Question 5

How does fluid shift

Answer 5

Between the body and the outside world
- intake and output
Between fluid compartment
- osmosis, diffusion and active transport

Question 6

What is osmosis

Answer 6

Movement of a solvent (water) across a membrane to a region of higher concentration of solute
The of movement is dependent on the number of particles in the solution

Question 7

What is osmotic pressure

Answer 7

The hydrostatic pressure that must be applied to the solution of greater concentration to prevent water movement across a semi-permeable membrane separating 2 aqueous solution os unequal concentrations

Question 8

What is osmolarity

Answer 8

Number of osmoles per L

Question 9

What is osmolality

Answer 9

Number of osmolality per kg

Question 10

What is plasma osmolality

Answer 10

Posm = 2[Na] + glucose + urea = 290mosmol/kg

Note the absence on plasma proteins (albumin) and colloid osmotic pressure

Question 11

Consideration is practical fluid balance

Answer 11

Composition of the IV fluid
Assessment of the hydration state
Rules for fluid therapy
Tackling electrolyte imbalance

Question 12

What are crystalloids

Answer 12

Small molecules/solutes
Water +salt +/- sugar
They are sterile, safe, cheap and have short intra-vascular half life

Question 13

Where does 0.9% NaCl remain

Answer 13

ECF
Good for resus
Interstitial:intravascular 2:1

Question 14

Where does 5 % dextrose distribute to

Answer 14

All compartments following metabolism of glucose

Question 15

What is Hartman’s

Answer 15

Compounds sodium lactate much similar in physiological composition to plasma

Question 16

What are colloid solution

Answer 16

Used for plasma expansion but are less used these days 
they are large MW compounds 
Non-synthetic such as albumin
Synthetic - gelatin, dextran or starch
Suspended in isotonic fluid (NaCl)
Longer intravascular half life
1:1 volume replacement

Question 17

What is the problem with synthetic colloids

Answer 17

Anaphylaxis
Affect coagulation - anti-thrombotic
Deposit in the reticule-endothelial system causing pruritis
Renal function can be affected (starch)

Question 18

How to asses fluid status

Answer 18

History - thirst 
Exam
Mucous men - dry 
Dec skin turgor
Dec cap refill
Dec JVP
Dec Blood pressure
Dec urine output

Question 19

Mild dehydration is what and causes what

Answer 19

4% of TBW
3L
Reduced skin turgor
Dry membranes

Question 20

Moderate dehydration is what and causes what

Answer 20

5-8% TBW
4-6L
Oliguria, tachycardia
Hypotension

Question 21

What is severe dehydration

Answer 21

8-10%
7 L
CVS compromise
Confusion/coma

Question 22

Investigations of dehydration

Answer 22

FBC 
Haemoconcentration 
Anaemia
Transfusion requirement blood loss +dehydration can make it difficult to work out how much to transfuse as if dehydrated Hb may be higher than it actually is 
Creatinine U&E
Dehydration inc Na inc urea 
Electrolyte imbalance 
Renal dysfunction inc creatinine and inc urea

Question 23

What happen to the sodium infused in

Answer 23

Remain in the ECF

Question 24

What does glucose and water do

Answer 24

Expands the entire TBW

Question 25

Indication for dextrose 5%

Answer 25

Dehydration | Going to be dehydrated

Question 26

What are the electrolyte requirements

Answer 26

Sodium requirement =2mmol/kg/day 150mmol in 1000mls 0.9% saline Potassium requirement = 1mmol/kg/day 60-70mmols in 24 hrs

Question 27

Potassium replacement

Answer 27

Hypokalaemia can be a highe loss if chronic is acute can be a small losss due to only the extracellualr being measurable cannot tell the actual deficit Correct slowly is asymptomatic 20-40mmol KCL/l 0.9% saline Reestimate by doing the U and Es frequently Aim for high normal levels in arrhythmias

Question 28

Forms you can get plasma in

Answer 28

``` FFP - contains plasma proteins, labileclotting factors, stored -30 for >1year ABO and Rh compatible HAS - 4.5%, 20% Controversy over sue pasteurised - glass bottle Recombinant Flexible packs ```

Question 29

Platelets how many donation needed per bag

Answer 29

4-6 donation= 1 adult pack

Question 30

Storage of platelet

Answer 30

22 degrees | 5 days