Fluid things Flashcards
crystalloids are defined as solutions with solutes no larger than xxxxxx Da.
no larger than 500 dalton (500 g/mole)
How much time does it take for electrolytes from IV fluids to distribute between IV and interstitial space?
20-30 min
What is the osmolality of 0.45% saline?
154 mOsm/L
What is the osmolality of 7.5% NaCl?
2566 mOsm/L
by how much does a 4mL/kg 7.5% NaCl bolus expand intravascular volume?
12-16 mL/kg
List cardiovascular benefits from HTS besides volume expansion
- decreased afterload - transient arteriolar vasodilation»_space; increaed CO
- reduced endothelial swelling
- positive inotropic effect (weak)
What is the mechanism of action for HTS-induced hypotension?
acute hyperosmolality
* central vasomotor center inhibition»_space; bradycardia
* peripheral vasomotor effects»_space; vasodilation
What are the immunomodulatory effects of HTS?
anti-inflammatory - suppression of neutrophil respiratory burstactivity and cytotoxic effects
What are HES synthesized from?
amylopectin - from starch of corn or potatoes
What are the descriptive characteristics of HES?
- concentration
- weight-average molecular weight
- (number-average molecular weight, i.e., median)
- molar substitution
- C2:C6 hydroxyethyl substitution ratio
What is the renal threshold?
45-60 kDa
Describe molar substitution of HES
number of hydroxyethyl substitutions per glucose molecule –> e.g., tetrastarch is 0.4 –> means 4 substitutions
What characteristics will give a HES product a longer half-life?
- higher molar substitution
- higher weight-average molecular weight
- higher C2:C6 ratio (C2 HE residues inhibit alpha-amylase activity compared to C6)
Why is the half-life of HES longer in dogs compared to people?
higher serum alpha-amylase activity
Where are HES excreted?
- 70% kidneys
- reticuloendothelial system - liver speen lnn - after HES distribute in tissues
- biliary excretion
List 5 potential adverse effects of HES
- AKI
- coagulopathy
- proinflammatory effects
- anaphylaxis
- volume overlaod
What are the 2 theories for how HES cause AKI?
Cellular uptake causing swelling - i.e., osmotic nephrosis
* proximal tubular cells take up HES via pinocytosis
* causes accumulation of IC water»_space; cytoplasmic»_space; cellular swelling»_space; altered integrity and function»_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
List the coagulopathic effects of HES
- 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
Which plasma product has the higher oncotic pressure and albumin concentration?
cryopoor plasma
What were the findings of the SAFE study?
4% HSA versus 0.9% Saline did not improve 28-day mortality in human ICU patients
How do you calculate the albumin deficit?
albumin deficit (g) = 10 x 0.3 x BW (kg) x (desired albumin - patient albumin)
What hypersensitivity reactions have been observed in dogs receiving human serum albumin?
type I and III
Where do immune-complexes from type III hypersensitivity reactions predominantly accumulate?
- glomeruli
- arteries (leukocytoclastic vasculitis)
- synovia
At what osmolality or pH should fluids not be administered through a peripheral IV catheter?
Osmolarity > 700 mOsm/L
pH < 5 or > 9
