Perioperative Fluid Therapy (Exam IV) COPY

Question 1

What are the primary intracellular and extracellular cations?

Answer 1

Intra: K+
Extra: Na+

Question 2

Difference between Diffusion and Osmosis:

Answer 2

Diffusion: Moves from higher to lower concentration
Osmosis: Moves from a lower to higher concentration

Question 3

Osmotic pressure is affected by:

Answer 3

• Temperature
• Number of molecules
• Volume (inversely related)

Question 4

What is the formula for osmotic pressure?

Answer 4

P = (NRT) / V

P = pressure
N = # of molecules
R = constant
T= temp
V= volume

Question 5

What is osmolarity?

Answer 5

particles / Liter of solvent

Question 6

Higher osmolarity = _______ “pulling power”.

Answer 6

higher

Question 7

What is osmolality?

Answer 7

particles / kg of solvent

Question 8

What is normal serum osmolality?

Answer 8

280 - 290 mOsm

Question 9

What three components produce oncotic pressure?

Answer 9

1. Albumin (65-75%)
2. Globulins
3. Fibrinogen

Question 10

What is the normal daily fluid intake?

Answer 10

• 750 mL from solids
• 350 mL from metabolism
• 1400 mL liquid intake

Question 11

What is the normal daily fluid output?

Answer 11

• 1000 mL insensible loss
• 100 mL GI loss
• 0.5 - 1 mL/kg/hr UO

Question 12

Urine output makes up approximately ___% of daily water loss.

Answer 12

60%

Question 13

This urine output regulator alters renal water excretion in response to plasma tonicity:

Answer 13

ADH

Question 14

___ is activated with an increase in fluid volume.

Answer 14

ANP

Question 15

Aldosterone regulates ___ and ___ levels.

Answer 15

Na and K

Question 16

What sensors does the body have for fluid balance?

Answer 16

• Hypothalamic osmoreceptors
• Low pressure baroreceptors
• High pressure baroreceptors

Question 17

Where are high pressure baroreceptors located?
Low pressure baroreceptors?

Answer 17

• High pressure → carotid sinus & aorta
• Low pressure → large veins & RA

Question 18

Where is renin release from?
What does it do?

Answer 18

Renin (released from juxtaglomerular cells) cleaves angiotensinogen to make angiotensin I.

Question 19

How long does RBC replacement via erythpoiesis take?

Answer 19

4-8 weeks

Question 20

Where is aldosterone released from?
What does it do?

Answer 20

• Adrenal Cortex
• Na⁺ and H₂O retention

Question 21

Describe the distribution of crystalloids through the ECF in 20 mins. What about 30 mins?

Answer 21

20 mins: 70% intravascular
30 mins: 50% intravascular

Question 22

What issues are associated with normal saline use?

Answer 22

• Hemodilution
• ↑ Cl⁻ and K⁺
• Hyperchloremic metabolic acidosis
• ↑AKI & RRT in critical care patients

Question 23

How does lactated ringers osmolarity compare to that of NS?

Answer 23

LR osmolarity is lower than NS.

Question 24

Why is lactate added to LR?

Answer 24

Buffering capacity

Question 25

___ will excrete excess water faster than NS.

Answer 25

LR *Suppresses ADH secretion, allows for diuresis*.

Question 26

Lactate formation relies on what?

Answer 26

Hepatic metabolism

Question 27

Why do we not want to give D5W (Dextrose solutions) for volume expansion?

Answer 27

water moves freely between all compartments = turns into free water

Question 28

True or False: Dextrose 5% can be used for caloric intake in diabetics?

Answer 28

FALSE: Dextrose **10%** could be used for caloric intake in diabetics

Question 29

What are the hemodilutionary effects of colloid administration?

Answer 29

- ↓ plasma viscosity - ↓ RBC aggregation

Question 30

What fluid "class" can have adverse effects on the immune, coagulation, and renal systems?

Answer 30

Colloids

Question 31

What is Hetastarch? What is it derived from?

Answer 31

Modified natural polymers of amylopectin derived potato or corn/maize.

Question 32

How much of intravascular volume expansion from hetastarch is still present in the system 90 minutes later?

Answer 32

70-80%

Question 33

What are side effects of hetastarch?

Answer 33

- Coagulopathy - Renal dysfunction

Question 34

What is Dextran?

Answer 34

Highly branched polysaccharide

Question 35

What type of surgery is dextran useful for? Why?

Answer 35

Microvascular surgery due to inhibition of clotting cascade.

Question 36

What can dextran interfere with? (besides the clotting cascade)

Answer 36

Blood crossmatching due to coating of RBCs

Question 37

What are signs/symptoms of low intravascular volume?

Answer 37

* Tachycardia * Decreased Pulse Pressure (Narrow) * Hypotension * Decreased Cap refill

Question 38

What are signs/symptoms of high intravascular volume?

Answer 38

- ↑ capillary hydrostatic pressure - Edema - ↓ tissue O₂ - Poor wound healing - Dysfunctional coagulation

Question 39

What are standards for NPO status?

Answer 39

Question 40

What is the classic formula for NPO/maintenance fluid replacement? **4-2-1 Rule**

Answer 40

1st 10kg = 4 mL/kg/hr → 40mL/hr 2ⁿᵈ 10kg = 2 mL/kg/hr → 20mL/hr Each 1kg over 20kg = 1mL/kg/hr

Question 41

What would the maintenance fluid rate (4-2-1 rule) be for a 110kg patient?

Answer 41

40 mL + 20 mL + (90 x 1mL/kg/hr) → **150 mL/hr**

Question 42

What would the maintenance fluid rate be for a 18kg toddler?

Answer 42

1st 10kg → 40 mL 2ⁿᵈ 8kg → 16 mL = **56 mL/hr**

Question 43

How is fluid deficit replaced in a surgery?

Answer 43

½ calculated volume in 1st hour ¼ volume in 2ⁿᵈ hour ¼ volume in the 3rd hour

Question 44

How is fluid deficit calculated?

Answer 44

hours NPO x 4-2-1 maintenance rate

Question 45

How is hourly intraoperative volume replacement calculated?

Answer 45

Deficit + Maintenance + EBL

Question 46

How much blood do lap sponges hold? How much blood do Raytech's hold? How much blood does a 4x4 hold?

Answer 46

100 mL 20 mL 10 mL

Question 47

What would the replacement volume rate be for a surgical case that exhibits minimal (robotic, toe pin, cataract, etc.) evaporative/redistributive volume loss?

Answer 47

0-2 mL/kg/hr

Question 48

What would the replacement volume rate be for a surgical case that exhibits moderate evaporative/redistributive volume loss?

Answer 48

2-4 mL/kg/hr

Question 49

What would the replacement volume rate be for a surgical case that exhibits severe (open belly) evaporative/redistributive volume loss?

Answer 49

4-8 mL/kg/hr

Question 50

How is the Parkland burn resuscitation formula calculated? What % of TBSA from 2nd or 3rd degree burns are required for initiation of this resuscitative effort?

Answer 50

4 mL/kg/ %BSA burned 20% TBSA

Question 51

Why might the Parklands burn formula be altered for kids?

Answer 51

Proportions of their body are not equal. Heads are much larger, therefore the head may be a greater % of Total burn

Question 52

How is the volume calculated via the parkland formula given?

Answer 52

½ in the 1st 8 hours ½ in the next 16 hours

Question 53

Studies of Goal Directed Therapy have shown decreases in all of these adverse effects of fluid resuscitation:

Answer 53

* Less AKI * Less Resp. Failure * Less Wound infection * Less mortality

Question 54

What are the general characteristics of goal directed therapy?

Answer 54

- Volume administration based on hemodynamics - 1-3 mL/kg/hr crystalloid - 250cc fluid challenges for ↓SV - 1:1 colloids for blood loss

Question 55

What is normal SVV? (PPV, SPV as well)

Answer 55

10 - 15 % ## Footnote This is over 30 seconds

Question 56

What are the limits to assessment of volume via arterial waveform monitoring?

Answer 56

**L**ow HR and/or RR **I**rregular HR **M**echanical ventilation **I**ncreased abdominal pressure **T**horax open **S**pontaneous ventilation

Question 57

Colloid particles are separated via a centrifuge. T/F?

Answer 57

False. Colloid particles cannot be separated from crystalloid solution (via centrifuge or filtration).