Interstitial Edema

Question 1

What defines edema?

Answer 1

An excess of salt and water in the extracellular space.

Question 2

Diseases associated with which organ systems is edema correlated with?

Answer 2

Renal, cardiac, and hepatic systems

Question 3

What are the two types of edema in terms of location?

Answer 3

1. Generalized (everywhere, first indicated by facial puffiness)
2. Localized (specific parts of the body)

Question 4

What are 2 pressures that increase in the body from standing for some time?

Answer 4

1. Venous pressure

2. Capillary pressure (due to venous pressure)

Question 5

Normally, the lymphatic system can do what to maintain proper fluid balance?

Answer 5

Take up extra interstitial fluid and return it to the vascular space.

Question 6

What is a result of the pressures that accumulate from standing for long periods of time?

Answer 6

Increased flow to the interstitial fluid from the vascular space.

Question 7

How does fluid return from the interstitial space to the vascular system through the lymph system?

Answer 7

Skeletal muscles to contract and compress the veins and lymphatic system in order to propel the fluid upward through the valves so that they can dump back into the heart/vascular system.

Question 8

If a standing person does not contract their skeletal muscles for fluid flow, what will be the consequence?

Answer 8

Transduction of fluid will exceed the lymphatic return causing interstitial edema.

Question 9

What is one organ that is particularly sensitive to proper fluid balance?

Answer 9

Lungs

Question 10

How does pulmonary edema occur?

Answer 10

The slightest increases in hydrostatic pressure in the pulmonary system results in pulmonary edema.

Question 11

What does pulmonary hypertension result in?

Answer 11

Pulmonary edema

Question 12

How does pulmonary edema affect lung compliance?

Answer 12

It decreases lung compliance.

Question 13

What are 2 consequences of decreased lung compliance?

Answer 13

1. Lung inflation becomes much more difficult.

2. Gas exchange is severely impaired.

Question 14

What will left-sided heart failure do to the pulmonary system?

Answer 14

Cause pulmonary edema do to the buildup of fluid in the pulmonary circulation (pulmonary hypertension)

Question 15

What effect does right-sided heart failure have on the circulation and what is its relationship with edema? (2)

Answer 15

1. Increases venous pressure of lower extremities and abdominal viscera.
2. Fluid transduced from the hepatic and intestinal capillaries may leave the interstitial space and enter the peritoneal cavity (this condition is called ascites)

Question 16

What is ascites?

Answer 16

When fluid transduced from the hepatic capillaries leave the interstitial space and enter the peritoneal cavity.

Question 17

What is nephrotic syndrome?

Answer 17

Renal disease where protein is lost in the urine.

Question 18

What are the consequences of nephrotic syndrome? (3)

Answer 18

1. Decrease in plasma colloid osmotic pressure
2. Decrease in ability to retain capillary fluid
3. Generalized peripheral edema

Question 19

How are colloid osmotic forces related to pregnancy?

Answer 19

Maternal plasma protein levels fall when their synthesis does not keep pace with the expanding plasma volume and the nutritional demands of the fetus. This leads to edema in the extremities.

Question 20

What happens if you have protein malnutrition?

Answer 20

The lower capillary osmotic pressure leads to edema in the extremities.

Question 21

What is one scenario opposite of decreased colloid osmotic forces that result in peripheral edema?

Answer 21

Dehydration, which then pulls fluid from the interstitial space into the vascular system.

Question 22

When do you see reduced turgor of the interstitial space?

Answer 22

In dehydration. Easily noticed by pinching the skin and seeing slow elastic retraction.

Question 23

Inflammation causes the release of histamines and cytokines. What do these do?

Answer 23

These are vasodilators.

Question 24

What else are cytokines responsible for instead of vasodilation/

Answer 24

1. Widening of the interendothelial clefts

2. A fall in the reflection coefficient (sigma)

Question 25

What is the net effect of the release of histamines and cytokines in inflammation?

Answer 25

Enhanced filtration of fluid from the capillary lumen to the interstitial fluid (aka swelling).

Question 26

How does cerebral edema occur in severe head injuries?

Answer 26

Breakage of the blood brain barrier endothelial cells. Cerebral edema can be dangerous because the rigid skull prevents expansion.

Question 27

How does edema occur after ischemia (blood flow blockage)?

Answer 27

Blood vessels deteriorate causes 1. Increase in hydraulic movement/conductivity, 2. Decrease in reflection coefficient (sigma). Reperfusion then brings in fluid and these deteriorated vessels cannot control fluid flow.

Question 28

What is reperfusion?

Answer 28

When blood flow is re-established after an ischemic attack.

Question 29

What is a consequence from a surgery that removed the lymph nodes or if the flow through a lymph node is blocked?

Answer 29

Reduction in lymphatic drainage. Causes local edema upstream of the affected lymph node.