Fluid things

Question 1

crystalloids are defined as solutions with solutes no larger than xxxxxx Da.

Answer 1

no larger than 500 dalton (500 g/mole)

Question 2

How much time does it take for electrolytes from IV fluids to distribute between IV and interstitial space?

Answer 2

20-30 min

Question 3

What is the osmolality of 0.45% saline?

Answer 3

154 mOsm/L

Question 4

What is the osmolality of 7.5% NaCl?

Answer 4

2566 mOsm/L

Question 5

by how much does a 4mL/kg 7.5% NaCl bolus expand intravascular volume?

Answer 5

12-16 mL/kg

Question 6

List cardiovascular benefits from HTS besides volume expansion

Answer 6

• decreased afterload - transient arteriolar vasodilation&raquo_space; increaed CO
• reduced endothelial swelling
• positive inotropic effect (weak)

Question 7

What is the mechanism of action for HTS-induced hypotension?

Answer 7

acute hyperosmolality
* central vasomotor center inhibition&raquo_space; bradycardia
* peripheral vasomotor effects&raquo_space; vasodilation

Question 8

What are the immunomodulatory effects of HTS?

Answer 8

anti-inflammatory - suppression of neutrophil respiratory burstactivity and cytotoxic effects

Question 9

What are HES synthesized from?

Answer 9

amylopectin - from starch of corn or potatoes

Question 10

What are the descriptive characteristics of HES?

Answer 10

• concentration
• weight-average molecular weight
• (number-average molecular weight, i.e., median)
• molar substitution
• C2:C6 hydroxyethyl substitution ratio

Question 11

What is the renal threshold?

Answer 11

45-60 kDa

Question 12

Describe molar substitution of HES

Answer 12

number of hydroxyethyl substitutions per glucose molecule –> e.g., tetrastarch is 0.4 –> means 4 substitutions

Question 13

What characteristics will give a HES product a longer half-life?

Answer 13

• higher molar substitution
• higher weight-average molecular weight
• higher C2:C6 ratio (C2 HE residues inhibit alpha-amylase activity compared to C6)

Question 14

Why is the half-life of HES longer in dogs compared to people?

Answer 14

higher serum alpha-amylase activity

Question 15

Where are HES excreted?

Answer 15

• 70% kidneys
• reticuloendothelial system - liver speen lnn - after HES distribute in tissues
• biliary excretion

Question 16

List 5 potential adverse effects of HES

Answer 16

• AKI
• coagulopathy
• proinflammatory effects
• anaphylaxis
• volume overlaod

Question 17

What are the 2 theories for how HES cause AKI?

Answer 17

Cellular uptake causing swelling - i.e., osmotic nephrosis
* proximal tubular cells take up HES via pinocytosis
* causes accumulation of IC water&raquo_space; cytoplasmic&raquo_space; cellular swelling&raquo_space; altered integrity and function&raquo_space; tubular injury - i.e., vacuolization

Hyperoncotic-induce renal dysfunction
* increased plasma oncotic pressure while there is a decreased renal hydrostatic pressure (from decreased perfusion)
* low GFR

Question 18

List the coagulopathic effects of HES

Answer 18

• decreased PLT function (impairs GPIIb/IIIa receptor; colloid osmotic shrinkage of platelets)
• decreased vWF and VIII
• decreased factor VIII-related antigen and factor VIII ristocetin factor
• impairs FXIII and fibrin interactions
• profibrinolytic when incoorporatd into a clot
• dilution of platelets and coag factors

Question 19

Which plasma product has the higher oncotic pressure and albumin concentration?

Answer 19

cryopoor plasma

Question 20

What were the findings of the SAFE study?

Answer 20

4% HSA versus 0.9% Saline did not improve 28-day mortality in human ICU patients

Question 20

How do you calculate the albumin deficit?

Answer 20

albumin deficit (g) = 10 x 0.3 x BW (kg) x (desired albumin - patient albumin)

Question 21

What hypersensitivity reactions have been observed in dogs receiving human serum albumin?

Answer 21

type I and III

Question 22

Where do immune-complexes from type III hypersensitivity reactions predominantly accumulate?

Answer 22

• glomeruli
• arteries (leukocytoclastic vasculitis)
• synovia

Question 23

At what osmolality or pH should fluids not be administered through a peripheral IV catheter?

Answer 23

Osmolarity > 700 mOsm/L
pH < 5 or > 9