Exam #2: Hemodynamics I Flashcards
What are hemodynamic disorders?
Generally, hemostasis maintains the fluid portion of the CV system in balance; failure of hemostasis mechanisms that can lead to:
- Excessive bleeding
- Vessel occlusion by excessive blood clot formation
Describe normal fluid hemostasis.
- Fluid flows out of the arterial end of microcirculation into the ISF
- Fluid returns at the venous end of microcirculation
Whatever is leftover goes into the lymphatic system & is drained into the thoracic duct–>subclavian vein
What is edema?
Increased ISF that cannot be completely dealt with by the lymphatics
What is the difference between transudate and exudate?
Transudate= edema caused by increased capillary hydrostatic pressure or reduced plasma protein, which results in protein-poor fluid with a low specific gravity ( <1.012)
What is a hydrothorax?
Fluid in the pleural space
What is hydropericardium?
Fluid is the space between the heart and pericardium
What is hydroperitoneum?
Ascites, fluid in the peritoneal space
What are the five potential etiologies of edema?
1) Increased hydrostatic pressure
2) Decreased plasma oncotic pressure (low protein)
3) Sodium & water retention
4) Lymphatic obstruction
5) Inflammation
Draw the algorithm that outlines the etiologies of edema.
N/A
What generally causes edema resulting from a generalized increase in hydrostatic pressure?
Congestive heart failure–>compromised right ventricular function causes backup in the venous circulation
What is pitting edema?
Finger-shaped depression remaining after pressing on skin with a finger
What protein is mostly responisble for maintaining colloid osmoitc pressure?
Albumin
What causes hypoalbuminemia?
1) Malnutrition
2) Decreased hepatic synthesis i.e. liver failure or cirrhosis
3) Nephrotic Syndrome
What is ascites commonly caused by?
Advanced liver cirrhosis
What is anasarca?
A term that describes severe general edema that is usually due to a lack of oncotic pressure
What is the earliest sign of anasarca?
Periorbital edema
How does Na+ retention lead to edema?
- Increased Na+ in the circulation causes an obligate associated shift of water intravascular space
- The effect is 2-fold: 1) increased in hydrostatic pressure due to volume expansion, & 2) dilution of intravascular fluid & deceased oncotic pressure
- Edema results
How does inflammation lead to edema?
Increased vascular permeability leads to a leaking of fluid into the extracellular space
*****Note that this fluid is PROTEIN-RICH & called “Exudate”
What does lymphatic obstruction lead to? What are two of the common causes of lymphedema?
Lymphedema i.e. edema resulting from any type of lymphatic obstruction
1) Inflammation w/ fibrosis–>filariasis
2) Neoplasia