Edema and congestion

Question 1

what happens when hydrostatic pressure > oncotic pressure?

Answer 1

fluids enter interstitial space

Question 2

what happens when oncotic pressure> hydrostatic pressure

Answer 2

net reabsorption of fluid

Question 3

causes of increased hydrostatic pressure

Answer 3

impaired venous return

arteriolar dilation

Question 4

causes of impaired venous return

Answer 4

CHF

constrictive pericarditis

Ascites

venous obstruction/ compression: thrombi, mass effect, lower extremity inactivity due to dependency

Question 5

causes of arteriolar dilation

Answer 5

heat

neurohumoral dysregulation

Question 6

how does L heart failure contribute to edema

Answer 6

increased hydrostatic pressure in pulmonary capillaries causes transudate to enter lung alveoli and interstitium and produce pulmonary edema

Question 7

how does R heart failure contribute to edema

Answer 7

increased hydrostatic pressure in the vena cava causes and increase in transudate in the BLE and interstitium, producing pitting edema

Question 8

causes of reduced plasma oncotic pressure

Answer 8

nephrotic syndrome

ascites

malnutrition

protein-losing gastropathy

Question 9

how does nephrotic syndrome contribute to decreased oncotic pressure

Answer 9

increased salt/ water cant correct plasma volume deficits and plasma proteins continue to persist

Question 10

consequences of decreased oncotic pressure

Answer 10

edema

reduced intravascular volume

renal hypoperfusion

secondary hyperaldosternism

Question 11

causes of lymphatic obstruction

Answer 11

inflammation

neoplasm

postsurgical

postirradiation

Question 12

how does lymph obstruction contribute to edema

Answer 12

normally, more fluid is filtered into the interstitial spaces than is reabsorbed into the vascular bed and is removed by the lymphatics.

when there is a lymph obstruction there is n reabsorption of fluid from the interstitial spaces and vascular beds

Question 13

how does sodium retention cause edema?

Answer 13

1. intravascular fluid expansion from water following sodium increases the hydrostatic pressure
2. dilution of fluids causes decreased oncotic pressure

Question 14

causes of sodium retention

Answer 14

excessive salt intake with renal insufficiency

increased tubular reabsorption of sodium

renal hypoperfusion

increased RAAS

Question 15

how does inflammation contribute to edema

Answer 15

increases permeability of venules

Question 16

what is myxedema

Answer 16

A collection of fluid caused by deposition of glycosaminoglycans (mucopolysaccharides) in various tissues.

Question 17

what causes myxedema

Answer 17

T cell cytokines stimulate fibroblasts to synthesize increased amounts of hyaluronic acid

Question 18

whats the difference between and edema and an effusion

Answer 18

Edema= fluid in interstitial spaces

Effusion: fluid in cavity

Question 19

how does edema present with renal impairment?

Answer 19

generalized edema

periorbital edema

Question 20

how does edema present in subQ tissues

Answer 20

influenced by gravity (dependent edema)

can impair wound healing

Question 21

how does edema present in the brain

Answer 21

narrowed sulci with distended gyri

grossly swollen with evidence of compression against the underlying skull

Question 22

how does edema present in the lungs

Answer 22

lungs 2-3x normal weight

frothy blood-tinged fluid made of extravasated cells, air and transudate

since it impedes oxygen diffusion, it makes a favorable environment for infection

Question 23

what do effusions typically look like

Answer 23

protein poor translucent straw-colored fluid

except peritoneal effusion caused y lymph obstruction, which appear milky due to the presence of lipids absorbed from the gut

Question 24

Differentiate between hyperemia and congestion

Answer 24

hyperemia is an active process that involves dilation leading to increased blood flow, turning tissues red

Congestion is a passive process caused by the decreased outflow of blood from a tissue

Question 25

What do congested tissues typically look like

Answer 25

dusky reddish-blue due to cyanosis and stasis f RBC;s

Question 26

differentiate the morphology of acute LVF and RVH

Answer 26

**Acute LVF causes pulmonary edema:** engorged alveolar capillaries, alveolar septal edema and focal intra alveolar hemorrhage **Acute RVF causes liver congestion:** distended central vein sinusoids with centrilobular hepatocyte ischemic necrosis and periportal hepatocytes with possible fatty change

Question 27

differentiate the morphology of chronic LVF and RVH

Answer 27

**chronic LVF:** alveolar septae and interstitium become thick and fibrotic microhemorrhages cause bleeding into the alveolar space, which is phagocytized and degraded by macrophages **chronic RVF:** hemosiderin-laden macrophages with variable degrees of hepatocyte necrosis centrilobular regions are grossly red-brown and slightly depressed due to cell death and are accentuated against the tan uncongested liver