Chapter 168 Colloid Fluid Therapy Flashcards
Based on Starling’s equation, fluid movement across the vascular wall is affected by THESE
J =K[(Pc−Pi)−σ(πc −πi)]
- difference between hydrostatic (Pc – Pi) and oncotic (πc – πi) gradients,
Pc is the intravascular (capillary) hydrostatic pressure, Pi is the interstitial hydrostatic pressure, πc is the intravascular oncotic pressure, and πi is the interstitial oncotic pressure. K is that filtration coefficient that represents the ease with which fluids move across the membrane, whereas σ is the reflection coefficient that represents the pore size or permeability of the membrane.
What is added to a modified Starling equation?
the role of the endothelial glycocalyx, the small pore system responsible for maintenance of the semi-permeable vascular membrane.
Colloid osmotic pressure (COP)?
the oncotic pressure exerted by proteins or protein-like substances
liquid plasma?
never frozen plasma and refrigerated for up to 5 days
Plasma can be administered as a colloid in hypoproteinemic patients. How much of plasma would be needed to raise the albumin by 0.5g/dL?
Large volumes (20–25mL/kg) are required to raise the albumin by 0.5g/dL, assuming no major ongoing losses
Downside of Human Serum Albumin?
The possibility of severe and potentially fatal type III hypersensitivity reactions after initial or repeated exposure to HSA has been reported even though many hospitalized patients have been given HSA without significant adverse effects.
What do Hydroxyethyl starch solutions contain?
Hydroxyethyl starch solutions contain a polymer of glucose units derived from amylopectin and modified by substituting hydroxyethyl for hydroxyl groups at C2, C3, and C6 positions on the glucose units.
How are Hydroxyethyl starch solutions classified?
Hydroxyethyl starch solutions are also classified according to their molar substitution or the average number of hydroxyethyl residues per glucose unit, from which the terminology of hetastarch (0.7), hexastarch (0.6), pentastarch (0.5), and tetrastarch (0.4) is derived.
HES solutions exist in a variety of carrier solutions, including 0.9% NaCl and balanced/buffered crystalloids (e.g. lactated Ringer’s solution).
HOW ARE HES metabolized?
Most HES molecules are metabolized by alpha-amylase in the plasma and then cleared by renal excretion or tissue uptake. Small HES (<45–60 kDa) are not metabolized, but simply filtered by the glomerulus and excreted
If not metabolized or excreted, HES molecules are rec- ognized by the reticuloendothelial system as foreign and taken up by monocytes, macrophages, endothelial cells, proximal tubule (renal epithelial) cells, liver parenchymal cells, Schwann cells, and keratinocytes and incorporated into lysosomes where they are resistant to degradation
side effects of HES?
an increased risk of AKI requiring dialysis, coagulopathies, volume overload, and allergic reactions.
However, serious adverse effects are largely unreported in small animals.
Coagulopathies due to HES?
Coagulopathies are thought to occur secondary to a dilutional coagulopathy, platelet dysfunction, and increased fibrinolysis, as well as decreased concentrations of von Willebrand factor (vWF) and factor VIII
