Edema and Shock

Question 1

what is edema?

Answer 1

the accumulation of abnormal quantities of water in interstitial tissues and/or body cavitities

Question 2

compare transudates versus exudates

Answer 2

transudates: fluid accumulates without increased vascular permeability; clear fluid, low protein concentration

exudates: occur when vessels are damaged and leaky and are characterized by turbid fluid, high protein concentrations, and high total nucleated cell counts

Question 3

what are the 4 causes of edema?

Answer 3

1. increased intravascular pressure: venous obstruction results in increased hydrostatic pressure as blood backs up in venous system, with leakage of fluid into interstitial tissues; capillary permeability is not altered so no significant protein leakage occurs unless hella pressure increase; can be right (body vasculature edema) or left sided (pulmonary edema) heart failure
2. decreased intravascular osmotic pressure (hypoproteinemia): reduction in serum albumin decreases intravascular oncotic pressure and causes edema; due to either decreased hepatic synthesis of proteins, or increased protein loss through kidney or GI tract
3. increased vascular permeability: injury to vascular walls allows leakage of fluid, protein, and cells, and causes edema; increase in colloids within interstitium reduces reabsorption of fluid at the venous end of the capillary; the colloids eventually drained away by lymphatics but vascular inflammation causes increased vessel permeability so proteins move into the body cavities and/or tissue interstitial space; trauma and anoxia can also cause
4. lymphatic obstruction: blockage of lymph vessels causes edema; tissues fluids don’t get drained and accumulate in interstitium as edema; lymphangiectasia (lymph vessel dilation), usually due to lymph obstruction by tumor cells or a really tight bandage

Question 4

what are the 4 types of shock?

Answer 4

1. cardiogenic shock: cardiac pump failure
2. hypovolemic shock: loss of blood volume
3. distributive/vasogenic shock: venous pooling of blood that causes functional hypovolemia, sepsis, or anaphylaxis
4. obstructive shock: something preventing the heart from working (ex is hemopericardium leading to cardiac tamponade or an post aortic stenotic valve)

Question 5

describe cardiogenic shock

Answer 5

caused by insults that negatively affect the cardiac output (heart ability to pump blood)

ex: myocarditis, myocardial degeneration, electrolyte imbalances, valvular insufficiency

Question 6

describe hypovolemic shock:

Answer 6

caused by a sudden severe loss of blood volume

ex: acute hemorrhage, loss of fluid (intravascular and extravascular; with water deprivation, vomiting, or diarrhea), increased vascular permeability

Question 7

describe distributive (vasogenic) shock

Answer 7

caused by a sudden severe decrease in peripheral vascular resistance that causes extensive pooling of blood within the venous system and subsequent decreased venous return to the heart

ex. septic shock: from a bacterial infection in which large quantities are released into circulation

ex. anaphylactic shock: systemic manifestation of an acute hypersensitivity (allergic) response; histamine release causes vasodilation and increased vascular permeability with loss of intravascular fluid

ex. neurogenic shock: can occur following severe emotional stress, severe pain, or electrical shock; the result of massive autonomic discharges that cause extensive peripheral vasodilation, venous pooling, and tissue hypoperfusion